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The Best Source of Resveratrol

Tue, 01/18/2022 - 07:00

Is there any benefit to resveratrol? If so, should we get it from wine, grapes, peanuts, or supplements?

“Alcohol is a neurotoxin which can cause brain damage…[and] can cause cancer,” so perhaps the “consumption of alcohol…cannot be considered a healthy lifestyle choice” since it’s an addictive carcinogen. Cancer is only killer number two, though. Killer number one is heart disease, so what about the “French paradox”? Doesn’t moderate drinking protect against cardiovascular disease? I discuss this in my video Flashback Friday: The Best Source of Resveratrol.

As I’ve explained before, apparently there is no French paradox. It seems to have all just been a scam. That’s what started the whole “resveratrol fiasco,” though. During an episode on “60 Minutes,” it was suggested the red wine component resveratrol may account for the French paradox, and research took off. Even after it turned out there was no French paradox, research continued unabated, culminating in more than 10,000 scientific publications to date.

What did researchers find? “After more than 20 years of well-funded research, resveratrol has no proven human activity.” “One salient theme that consistently arises throughout this voluminous body of work underscores the fact that data from human studies regarding any biological effects of resveratrol is sorely lacking, despite its popularity as an over-the-counter nutritional supplement.” In fact, “the hype in the popular media regarding resveratrol…may indeed turn out to be nothing more than a slight-of-hand marketing device using…non-human research as a cover.” 

As you can see at 1:36 in my video, some studies are based on laboratory animal studies at massive doses—tens of milligrams of resveratrol per pound. If you do the math, this is how “various ‘experts’ claim that a daily dosage of 1 g/d is effective for treatments of diverse disorders in humans.” So how much red wine do you have to drink to get a gram of resveratrol a day? Why, just 5,000 cups a day. Not a fan of red wine? Don’t worry. You can just have a couple thousand gallons of white wine a day, 5,000 pounds of apples or grapes, 50,000 pounds of peanuts, a couple thousand pounds of chocolate, or nearly a million bottles of beer.

A million bottles of beer on the wall. A million bottles of beer. Take one down and pass it around, nine hundred and ninety-nine thousand, nine hundred and ninety-nine bottles of beer on the wall…. 

It doesn’t help matters when a “leading researcher on the beneficial properties of resveratrol…has been found guilty of 145 counts of fabrication and falsification of data,” throwing the whole field into turmoil. “Wine is good for those…who sell it!”

The resveratrol fiasco is not the only time dietary supplements have failed to fulfill their promise. “Notable examples” include beta-carotene pills and fish oil capsules. Studies in the 1990s showed taking beta-carotene in pill form actually increased cancer risk, and, in 2013, the thinking shifted on fish oil supplements from “No Proof of Effectiveness” to “Proof of No Effectiveness.” “The main lesson we should learn is that what makes biological sense and works in test tubes and animals does not always operate in humans.” 

“Resveratrol is one of approximately 25,000 components identified from food to date,” after all. Thinking in terms of whole foods “may be a better approach for health and disease prevention.” Instead of consuming just one chemical in wine extracted from grapes, why not eat the whole grape? “[F]or the prevention of diseases, the [whole] dietary grape seems to be the best-case scenario.”

This is part of a four-part series, which includes my videos:

KEY TAKEAWAYS

  • Alcohol is a neurotoxin that can cause brain damage and our number-two killer, cancer, but what about the so-called French paradox of moderate drinking protecting against cardiovascular disease, our number one killer?
  • During an episode of the television show “60 Minutes,” it was suggested that resveratrol, a component in red wine, may account for the French paradox, but it has been dismissed as a hoax. Despite that, research has continued and more than 10,000 scientific papers have been published to date.
  • Resveratrol has been found to have “no proven human activity,” and “the hype in the popular media regarding resveratrol…may indeed turn out to be nothing more than a slight-of-hand marketing device using…non-human research as a cover.”
  • Indeed, some animal studies used massive doses of tens of milligrams of resveratrol per pound to claim that a daily dosage of 1 g/d is an effective treatment of diverse human disorders, but you would need to drink 5,000 cups of red wine to get a single gram of resveratrol.
  • Other dietary supplements have also been found unable to fulfill their promises, such as beta-carotene pills and fish oil capsules. Beta-carotene in pill form has been found to increase, not decrease, cancer risk, and there is no proof of effectiveness with fish oil supplements.
  • “The main lesson we should learn is that what makes biological sense and works in test tubes and animals does not always operate in humans.”
  • Rather than consuming just one chemical in wine extracted from grapes, why not eat the whole grape?

Surprised about the French paradox? Learn more in What Explains the French Paradox?.

Can resveratrol supplements do more harm than good? Check out Resveratrol Impairs Exercise Benefits.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

Can Alcohol Cause Cancer?

Thu, 01/13/2022 - 07:00

If even light drinking can cause cancer, why don’t doctors warn their patients about it?

As I discuss in my video Can Alcohol Cause Cancer?, we’ve known about “the possible association of the consumption of alcohol with excessive mortality from cancer” for more than a hundred years. Though there is “accumulating evidence that alcohol drinking is associated with…pancreas and prostate cancer and melanoma,” we’re pretty certain it “increases the risk of cancer of oral cavity [mouth] and pharynx [throat], oesophagus, colorectum, liver, larynx [voice box] and female breast.” Current estimates suggest alcohol causes about 5.8 percent of all cancer deaths in these organs worldwide. 

How does it break down for men and women? As you can see at 0:44 in my video, alcohol causes mostly head, neck, and gastrointestinal cancers in men, whereas it causes mostly breast cancer in women. In fact, alcohol appears to cause more than 100,000 cases of breast cancer every year. Is that just among heavy drinkers, though? No. “All levels of evidence showed a risk relationship between alcohol consumption and the risk of breast cancer, even at low levels of consumption.” 

Eating a healthy diet, however, may help modulate that risk. Though alcohol increases the risk of breast cancer, “a fiber-rich diet has the opposite effect,” so eating more whole plant foods may be able to “ease the adverse effects associated with alcohol consumption.” As well, “alcohol has been shown to increase sex hormone levels,” like estrogen, which may increase breast cancer risk, but the opposite effect is seen when eating fiber-rich foods. “Fiber may bind estrogen in the colon thus increasing the fecal excretion of estrogens”—that is, help flush them out of the body. Even so, there does not appear to be any level of alcohol consumption that is completely safe from a cancer standpoint.

This is why we see commentaries in the medical literature suggesting “consumption of alcohol, an addictive carcinogen, cannot be considered a healthy lifestyle choice!” “Thus, the final message on [alcohol] should be clear: It is toxic, carcinogenic, teratogenic [birth defect–causing], and potentially addictive. By arguing otherwise, scientists can give the alcohol lobby and advertisers the opportunity to manipulate scientific evidence to generate profits” over public health. 

They do this by denying and distorting the evidence, while trying to distract the public’s attention. The alcohol industry, Big Booze, “appears to be engaged in the extensive misrepresentation of evidence about the alcohol-related risk of cancer,” activities that “have parallels with those of the tobacco industry,” Big Tobacco. These industries are somehow able to maintain an illusion of righteousness. “Alcohol and tobacco companies (like their junk food counterparts) increasingly seek to present themselves…as objective providers of health information about their products, and appropriate sources of educational resources for both adults and children…Health information and messages should come from health authorities, not the 21st century’s most successful drug peddlers.”

“Alcohol industries profit hugely from this disconnect and sometimes even appropriate the respectable cause of cancer prevention in order to promote their carcinogenic product. Case in point: Mike’s Hard Pink Lemonade. “Join the Fight” and “Drink Pink” are emblazoned on the six-pack, along with the pink breast cancer ribbon icon. More like “drink pink carcinogens!” “Mike’s Hard Lemonade (Mark Anthony Group) associated the creation of its Limited Edition Hard Pink Lemonade with the death of one of its employees from breast cancer.” In doing so, “ironically, it contributes to risk in the name of prevention.” Reminds me of KFC’s “Buckets for the Cure” campaign. If you don’t remember it, see for yourself at 3:21 in my video.

Cancer risk is one of the “things the alcohol industry won’t tell you,” but why doesn’t your doctor tell you? There is relatively little public awareness of the link, and the medical community remains largely silent. The medical profession may be getting more hip to corporate conflicts of interest in general, but “why are we ignoring the alcohol industry?” 

“Why is alcohol cancer’s best-kept secret?” Maybe it’s because the doctors are drinkers themselves and want to remain in “denial…that alcohol causes cancer.” 

Not only do most doctors drink, but a significant proportion admits to drinking while on call and encountering fellow physicians “whom they suspected were impaired by alcohol while on call.” Even though most doctors felt they “have an obligation to tell their patients that they use alcohol while on call, only 12% reported that they do so when using alcohol on call.” 

The industry “has identified the alcohol-causes-cancer message as a considerable threat. These powerful entities have a vested interest in maintaining the status quo of relative ignorance, uncertainty and denial among the general population and their trusted health advisers. In the face of this, it is time that health professionals set aside any leanings that might stem from their own drinking—good or bad—and convey unreservedly to their patients and the communities they serve that alcohol-causes-cancer.”

Cancer is only our second highest killer. The top killer is heart disease, so what about the French paradox? Doesn’t moderate drinking protect against cardiovascular disease? In that case, isn’t some alcohol beneficial overall? These are exactly the kinds of questions I set out to address in this four-part video series, which also includes.

KEY TAKEAWAYS

  • Alcohol consumption has been associated with excessive mortality from cancer for more than a century and causes mostly head, neck, and gastrointestinal cancers in men and breast cancer in women, even at low levels of intake.
  • Breast cancer risk is increased by alcohol consumption, which also elevates levels of sex hormones, such as estrogen, but fiber-rich diets have the opposite effect, so greater intake of whole plant foods may “ease the adverse effects associated with alcohol consumption.”
  • Within the medical literature, commentaries condemn alcohol as “toxic, carcinogenic, teratogenic [birth defect–causing], and potentially addictive,” while the alcohol industry has been accused of engaging in “extensive misrepresentation of evidence about the alcohol-related risk of cancer” and participating in activities that “have parallels with those of the tobacco industry.”
  • Big Booze has even appropriated cancer prevention causes in its marketing—e.g., Mike’s Hard Pink Lemonade with “Join the Fight” and “Drink Pink” emblazoned on the six-pack, along with the pink breast cancer ribbon icon.
  • The medical community has remained relatively quiet on the link between alcohol consumption and increased cancer risk, perhaps in part because most doctors drink themselves and a significant proportion admits to imbibing while on call.

I previously explore breast cancer specifically in my videos Breast Cancer and Alcohol: How Much Is Safe? and Breast Cancer Risk: Red Wine vs. White Wine.

Additional videos that speak to the connections between alcohol and cancer include Preventing Skin Cancer from the Inside Out and The Best Advice on Diet and Cancer.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Apple Peels Put to the Test for Chronic Joint Pain

Tue, 01/11/2022 - 07:00

Are the health benefits associated with apple consumption simply due to other healthy behaviors among apple-eaters?

Regular apple intake is associated with all sorts of benefits, such as living longer and, more specifically, a lower risk of dying from cancer. At 0:17 in my video Apple Peels Put to the Test for Chronic Joint Pain, you can see the survival curve of elderly women. Of those who do not eat an apple a day, nearly a quarter had died after 10 years and nearly half were gone after 15 years. In comparison, those who eat on average about half an apple a day don’t die as young, and those eating one daily apple—more than three and a half daily ounces, which is around a cup of apple slices—lived even longer. Is it possible that people who eat apples every day just happen to practice other healthy behaviors, like exercising more or not smoking, and that’s why they’re living longer? The study controlled for obesity, smoking status, poverty, diseases, exercise, and more, so the researchers really could compare apples to apples (so to speak). 

What they didn’t control for, however, was an otherwise more healthful diet. As you can see at 1:04 in my video, studies show that those who regularly eat apples not only have higher intakes of nutrients like fiber that are found in the fruit, but they’re also eating less added sugar and less saturated fat. In other words, they’re eating overall more healthful diets, so it’s no wonder apple-eaters live longer. But, is apple-eating just a marker for healthful eating, or is there something about the apples themselves that’s beneficial? You don’t know, until you put it to the test. 

Given that “athletes use a variety of common strategies to stimulate arousal, cognition, and performance before morning training,” subjects were randomly assigned to a caffeinated energy drink, black coffee, an apple, or nothing at all in the morning. Did the apple hold its weight? Yes, it appeared to work just as well as the caffeinated beverages. The problem with these kinds of studies, though, is that they’re not blinded. Those in the apple group knew they were eating an apple, so there may have been an expectation bias—a placebo effect—that made them unconsciously give that extra bit of effort in the testing and skew the results. You can’t just stuff a whole apple into a pill. 

That’s why researchers instead test specific extracted apple components, which allows them to perform a double-blind, placebo-controlled study where half the subjects get the fruit elements and the other half get a sugar pill, and you don’t know until the end who got which. The problem there, however, is that you’re no longer dealing with a whole food, removing the symphony of interactions between the thousands of phytonutrients in the whole apple.

Most of those special nutrients are concentrated in the peel, though. Instead of just dumping millions of pounds of nutrition in the trash, why couldn’t researchers just dry and powder the peels into opaque capsules to disguise them and then run blinded studies with those? Even just a “small amount could greatly increase phytochemical content and antioxidant activity…”

The meat industry got the memo. A study found that “dried apple peel powder decreases microbial expansion” in meat and protects against carcinogen production when it’s cooked. One of the carcinogens formed during the grilling of meat is a beta-carboline alkaloid—a neurotoxin that may be “a potential contributor to the development of neurological diseases including Parkinson’s disease.” Uncooked meat doesn’t have any. The neurotoxin is formed when meat is cooked, but you can cut the levels in half by first marinating it with dried apple peel powder, as you can see at 3:27 in my video.

Apple peel also cuts down on the amount of fecal contamination bacteria in meat. At 3:36 in my video, you can see a graph showing fecal bacteria growth in pork, beef, and turkey. After the addition of dried apple peel powder, the amount of fecal bacteria decreased. Apple peels can also inhibit the formation of genotoxic, DNA-damaging, heterocyclic amines (HCAs). As I show at 3:55 in my video, apple peels reduced the levels of these cooked meat carcinogens by up to more than half. “In view of the risks associated with consuming HCAs,” these cancer-causing compounds in meat, “there is a need to reduce exposure by blocking HCA formation such as by adding an ingredient during the cooking of meats to prevent their production”—an ingredient like apple peel powder. (Of course not cooking the meat to begin with be another way to reduce exposure…).

What about consuming apple peels directly? It was found that dried apple peel powder “exhibits powerful antioxidant and anti-inflammatory action,” but that was in mice. Does it have anti-inflammatory properties in people? You don’t know, until you put it to the test. 

A dozen people with moderate loss of joint range of motion and associated chronic pain were given a spoonful of dried apple peels a day for 12 weeks. As you can see at 4:45 in my video, month after month, their pain scores dropped and the range of motion improved in their neck, shoulders, back, and hips. The study’s conclusion? “Consumption of DAPP [dried apple peel powder] was associated with improved joint function and…pain reduction…” Why just “associated”? There was no control group so the subjects might have simply been getting better on their own, or the placebo effect could have come into play. Regardless, why not give apple peels a try by eating more apples?

If you want to learn more about meat carcinogens, see my video Essential Tremor and Diet, and check out Reducing Cancer Risk in Meat-Eaters for more on HCAs.

KEY TAKEAWAYS

  • After controlling for such factors as obesity, smoking status, and exercise, researchers studying elderly women found that those who eat an apple a day (more than 3.5 daily ounces, about a cup of apple slices) live longer than those who only eat about half an apple on average, who themselves live longer than those who do not eat an apple a day.
  • Studies show that subjects who regularly eat apples have higher intakes of fiber, which is found in the fruit, while eating less added sugar and less saturated fat.
  • An apple in the morning was found to work as well as a caffeinated energy drink or black coffee, but the study wasn’t blinded so the possibility of expectation bias, a placebo effect, cannot be dismissed.
  • Many special nutrients are concentrated in the peels of apples, and dried apple peel powder has been found to decrease “microbial expansion” in meat and protect against production of carcinogens during the cooking process.
  • Beta-carboline alkaloid, a neurotoxin that may contribute to the development of Parkinson’s and other neurological diseases, is one of the carcinogens formed during the grilling of meat, and its levels can be halved by first marinating the meat with dried apple peel powder before cooking.
  • Apple peels also reduce the amount of fecal contamination bacteria in meat and can inhibit DNA-damaging heterocyclic amines (HCAs) from forming.
  • A daily spoonful of dried apple peels for 12 weeks resulted in subjects with moderate loss of range of motion in their joints and related chronic pain to experience improvements in their necks, shoulders, backs, and hips, as well as lower pain scores.

Take a bite out of these apple videos:

For more on natural joint remedies, see:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Is Aloe Effective for Blood Pressure, Inflammatory Bowel, Wound Healing, and Burns?

Thu, 01/06/2022 - 07:00

I discuss the risks and benefits of aloe vera.

“Aloe vera is one of the most popular home remedies in use today, yet most physicians know little about it. In fact, most dismiss it as useless while their patients firmly believe in its healing properties…The usual tendency of most physicians and nurses is to dismiss as useless any popular remedy that can be purchased without a prescription. However, the aloe plant deserves a closer look because, surprising as it may seem, there may be a scientific basis for some of its uses.” It has, after all, been used medicinally for thousands of years by a number of ancient civilizations, but only recently has it been put it to the test, as I discuss in my video Is Aloe Effective for Blood Pressure, Inflammatory Bowel, Wound Healing, and Burns?.

What type of tests, though? Ones that investigate whether aloe can ameliorate damage to albino rat testicles or affect the cholesterol and estrogen responses in juvenile goldfish?

Indeed, if you inject aloe into the bloodstream of rats, their blood pressure drops, but if you feed it to humans, it doesn’t appear to have any blood pressure–lowering effect. Drinking aloe causes colorectal tumors to form in rats, whereas it appears to have anti-inflammatory effects on human intestinal lining in a petri dish. But, when put to the test for irritable bowel syndrome (IBD), no benefit was found for improving symptoms or improving quality of life in IBS patients. And, no benefit was found for IBD either.

What about the beneficial effects of aloe in wound healing? Evidently, they are “so miraculous as to seem more like myth than fact.” It works when you slice open guinea pigs or try to frostbite-off the ears of bunny rabbits, as you can see at 1:49 in my video (though, be warned about graphic images), but in people, it may make things worse. Indeed, “aloe vera…is associated with a delay in wound healing.” Researchers studied 21 women who had wound complications after having a cesarean or other abdominal surgery. Healing on their own took an average of 53 days, whereas the wounds treated with aloe vera gel required 83 days, taking 50 percent longer. Researchers thought the aloe would help, based on the animal studies, but when it was put to the test with people, it failed.

At this point in my research, it was looking like the only benefit of aloe was to improve the quality of cheap beef burgers, as one study found. But what about burns? Aloe has been used to treat burns since antiquity, but, in their ageless wisdom, people were also applying feces to burns, so I wouldn’t put too much faith in ancient medical traditions. 

That’s why we have science. 

What is the effectiveness of aloe vera gel compared with silver sulphadiazine as burn wound dressing in second-degree burns? “The introduction of topical antimicrobial agents has resulted in a significant reduction in burn mortality to date.” Silver sulfadiazine is the most commonly used, but, unfortunately, it may delay wound healing and become toxic to the kidneys and bone marrow. So, researchers tried it head-to-head against topical aloe gel. The result? The burns treated with aloe healed 50 percent faster, and the pain went away about 30 percent faster. The researchers concluded that aloe has “remarkable efficacy” in the treatment of burn injuries. Anyone see the flaw in that logic? What was this study missing? A placebo control group. Why would that matter? Remember, one of the side effects of the silver sulphadiazine is delayed wound healing. So, maybe the aloe worked better just because it wasn’t delaying healing but it wouldn’t have worked better than nothing at all. 

When it was put to the test against nothing—aloe vera in Vaseline versus the Vaseline alone—the aloe really did seem to help, speeding up healing by about a third. And, indeed, if you put all the studies together, aloe vera does appear to significantly speed up the healing of second-degree burns. Blistering burns, however, are thankfully less common than burns like sunburns, where your skin just turns red. What is the efficacy of aloe vera in the prevention and treatment of sunburn? An aloe vera cream was applied to study subjects 30 minutes before, immediately after, or both before and after they were burned with a UV lamp. Surprisingly, the “results showed that the aloe vera cream has no sunburn or suntan protection and no efficacy in sunburn treatment when compared to placebo.” 

It at least works for blistering burns, though, so should we keep some aloe vera gel in the medicine cabinet? The problem is that aloe vera you buy at the store may not contain any aloe vera at all. The product labels may say aloe vera is the first or second ingredient, but manufacturers apparently can be lying. “There’s no watchdog assuring that aloe products are what they say they are,” which means suppliers are on an honor system—but when health and nutrition are mixed with profit, honor, too often, goes out the window.

KEY TAKEAWAYS

  • Aloe vera, a popular home remedy, has been used medicinally for thousands of years.
  • Findings from studies using aloe vera on animals were significantly different from studies on humans. Rats’ blood pressure drops when they are injected with aloe, but there’s no blood pressure–lowering effect in people, for example, and although drinking aloe causes colorectal tumors to form in rats, it seems to be an anti-inflammatory to human intestinal lining, though no benefit was found for irritable bowel syndrome.
  • Aloe has been found to be beneficial in wound healing in animals, but humans’ wounds took 50 percent longer to heal when treated with aloe vera gel.
  • Topical aloe vera gel appears to significantly speed up the healing of blistering, second-degree burns, compared to both a placebo control and silver sulphadiazine, the most commonly used topical antimicrobial agent.
  • For milder burns, like sunburns, researchers found that aloe vera cream was not effective for the protection or treatment of sunburn, compared to placebo.
  • Aloe vera gels and creams may not actually contain any aloe vera despite it being listed as an ingredient, and, as the industry is not monitored, the deception may continue.

For more on aloe, see: 

What about natural remedies for high blood pressure? Check out:

To learn more about preventing and treating inflammatory bowel disease, see:

And, if you’re interested in wound healing, check out Benefits of Nutritional Yeast for Cancer and Speeding Recovery from Surgery with Turmeric.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

Top 10 NutritionFacts.org Videos of 2021

Tue, 01/04/2022 - 07:00

NutritionFacts.org arises from my annual review of the medical literature. With the help of a team of hundreds of volunteers, we churned through tens of thousands of scientific papers published in the peer-reviewed nutrition literature and are ramping up to break new records in 2022. How do I choose which studies to highlight? In general, I strive to focus on the most groundbreaking, interesting, and useful findings, but which topics resonate the most? The practical ones, offering cooking or shopping tips, or those that dissect the studies behind the headlines? Maybe the geeky science ones that explore the wonderfully weird world of human biology are the most popular. As you can see from the below list, the answer is a bit of all of the above.

 

#10 Dr. Greger in the Kitchen: Cran-Chocolate Pomegranate BROL Bowl

I’m sorry this originally came out after pomegranate season ended, but you should be able to find them now! This is one of my favorite ways to eat BROL (barley, rye, oats, and lentils) for breakfast.

My Basic BROL—found in The How Not to Diet Cookbook—can be used in all kinds of savory or sweet ways, packing in a lot of prebiotic nutrition and helping to tick off those grain boxes on your Daily Dozen Checklist. For extra credit, sprinkle some matcha on top.

 

#9 Kombucha’s Side Effects: Is It Bad for You?

What are the risks versus benefits of drinking kombucha? I’m glad I was finally able to post an update. *Spoiler Alert* There are better options. Check out What Are the Best Beverages?

 

#8 Do Angioplasty Heart Stent Procedures Work?

This was the first in a controversial seven-part video series documenting how stents perform compared to placebo (fake) surgery. Here are the next six in the series:

 

#7 The Scientific Consensus on a Healthy Diet

Tragically, the leading risk factor for death in the United States is the American diet—but that means we have the power to change it! The media likes to inflate the controversies, but the science has been clear for decades about the core tenets of healthy eating and living.

 

#6 Are Beyond Meat and the Impossible Burger Healthy?

That was a common question during my monthly Q&As so I did a deep dive and created a nine-video series on the topic, including:

For a healthful, whole-food veggie burger, check out my recipe for Black Bean Burgers from my first cookbook.

 

#5 Are Doctors Misleading Patients About Statin Risks and Benefits?

What is the dirty little secret of drugs for lifestyle diseases? If patients knew the truth of how little these drugs actually worked, almost no one would agree to take them. This was part of a four-part series on statins, which includes:

Another popular video of 2021 was How Low Should You Go for Ideal Cholesterol Levels?. I explore how having a so-called normal cholesterol in a society where it’s normal to drop dead of a heart attack isn’t necessarily a good thing.

 

#4 The Best Diet for Hypothyroidism and Hyperthyroidism

Thyroid health is another topic I got asked about a lot. In this video, I explore whether the apparent protection of plant-based diets for thyroid health is due to the exclusion of animal foods, the benefits of plant foods, or both. The other three videos in this series are:

One common cause of an underactive thyroid is autoimmune thyroiditis. Another popular video from this past year explores one tool for dealing with this friendly fire: Fasting for Autoimmune Diseases. See our fasting topic page for even more.

 

#3 The Best Diet for Fatty Liver Disease Treatment

Nonalcoholic fatty liver is now a leading cause of liver failure. In this video, I address the three sources of liver fat and how you can get rid of it.

 

#2 200-Pound Weight Loss Without Hunger

I’m excited people found this video as fascinating as I did. If you aren’t blown away by the eye-opening revelations, you may want to watch it a second time to fully absorb it all.

For more on healthy weight loss, check out my Evidence-Based Weight Loss presentation and my book How Not to Diet. (All proceeds from my books are donated to charity.)

 

#1 What Causes Cancer to Metastasize?

One of the reasons I love my work so much is that I love learning. That’s the first thrill. The second is being able to share the knowledge. In this video, I discussed that palmitic acid, a saturated fat concentrated in meat and dairy, can boost the metastatic potential of cancer cells through the fat receptor CD36.

I had never even heard of CD36 until recently! I followed this video with How to Help Control Cancer Metastasis with Diet and The Food That Can Downregulate the Metastatic Cancer Gene. I can’t wait to find out what I’m going to learn next year!

Speaking of discoveries, check out another popular video from this year, Boosting Anticancer Immunity with Forest Bathing. Visiting a forest can induce a significant increase in both the number and activity of natural killer cells, one of the ways our body fights off cancer. But why? The big reveal is in the follow-up: Why Does Forest Bathing Boost Natural Killer Cell Function?.

 

Join the New Plant-Based Living Email Series

Our new ten-week email series is a free resource to bring you simple takeaways and actionable tips on healthy eating. Whether you’re new to a whole food, plant-based lifestyle or would benefit from reminders on some of the key aspects of healthy evidence-based nutrition, this series is for you. Based on our popular Evidence-Based Eating Guide, a weekly email with even more tips and information will be delivered straight to your inbox. Click here to see the full list of topics and to sign up.

 

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Is It the Sugar, the Milk, or the Cocoa in Chocolate Causing Acne?

Thu, 12/30/2021 - 07:00

Is the link between chocolate and acne due to the sugar, the milk, or the cocoa in chocolate? Researchers put white chocolate, dark chocolate, baking chocolate, and cocoa powder to the test to find out.

A century ago, “diet was commonly used as an adjunct treatment for acne. During the 1960s, however, the diet–acne connection fell out of favor.” Why? Because of a study that purportedly “‘proved’ that chocolate had no influence on acne by comparing a chocolate bar to a pseudo chocolate bar composed of 28% hydrogenated vegetable oil, a food known to increase inflammatory markers.” It’s no wonder real chocolate didn’t come out looking so bad when compared to that pure trans-fat-laden fake chocolate. 

As well, in another study, small groups of medical students ate a variety of purported acne-causing culprits, and only about a third broke out. However, there was no control group for comparison. Nevertheless, these two studies, despite their “major design flaws, were sufficient to dissociate diet from acne in the minds of most dermatologists. Textbooks were revised to reflect this new academic consensus, and dermatologists took the stance that any mumblings about the association between diet and acne were unscientific and one of the many myths surrounding this ubiquitous disease.”

“Comments such as ‘The association of diet with acne has traditionally been relegated to the category of myth’ are commonplace in both the past and current [medical] literature…[however] the major textbooks of dermatology promulgate the notion that diet and acne are unrelated, yet rely only on 2 primary references”—those two flawed studies. So, this “present consensus within the dermatology community that diet and acne are unrelated has little or no factual support.” 

But there is reason to suspect chocolate consumption may be an issue, as I discuss in my video Does Cocoa Powder Cause Acne?. Blood was taken from subjects before and after they ate a couple bars of milk chocolate. It appears the milk chocolate “primes” some of their pus cells to release extra inflammatory chemicals when you expose them to acne-causing bacteria in a petri dish. “This may indeed represent one of the mechanisms that could explain the effects of chocolate on acne,” but how do we know it’s the chocolate and not the added sugar or milk?

If you survey teens on their acne severity and eating habits, there does appear to be a link to chocolate consumption, as you can see at 2:18 in my video, but is this wxassociation from people sprinkling cocoa powder in their smoothie or eating dark chocolate, or is it because of the added sugar and milk?

As you can see at 2:32 in my video, simply cutting down on sugary foods and refined grains can halve pimple counts in a few months, which was significantly better than the control group. You can view compelling before-and-after pictures at 2:38.

To tease out whether or not it was the sugar, researchers gave subjects milk chocolate or jelly beans. If it was just the sugar, then, presumably, acne would get worse equally in both groups. Instead, the chocolate group got worse, experiencing a doubling of acne lesions, whereas there was no change in the jelly bean group, as you can see at 2:52 in my video. So, apparently, it’s not just the sugar. Maybe there is something in chocolate, or is it only in milk chocolate? 

“There have been no studies assessing the effects of pure chocolate (made of 100% cocoa) on acne”…until researchers randomized 57 volunteers with “mild-to-moderate acne” into three groups, receiving white chocolate bars, dark chocolate bars, or no chocolate bars every day for a month. The dark chocolate wasn’t just any dark chocolate; it was 100 percent chocolate, like Baker’s chocolate. Unlike pure dark chocolate, white chocolate is packed with sugar and milk. What happened? Indeed, acne lesions worsened in the white chocolate group, but not in the dark chocolate or control groups. “According to this study, white but not dark chocolate consumption is associated with exacerbation of acne lesions.” 

Other studies, however, did show acne worsening on dark chocolate. As you can see at 3:55 in my video, when research subjects were given a single, large quantity of Ghirardelli baking chocolate, they broke out within days. “Significant increases were found” in the total average number of acne lesions within only four days. The same was found with more chronic consumption of dark chocolate. Subjects ate half a small chocolate bar a day for a month, and increased acne severity was reported within two weeks, as you can see, along with before-and-after pictures, at 4:11 in my video.

Was anything lacking in these two studies? Subjects were either given chocolate every day or one big load of chocolate, and their acne got worse. What didn’t these studies include? Long-time NutritionFacts followers should know the answer by now. The studies were missing a control group.

If you look at surveys, you’ll find that most people believe chocolate can cause acne. So, if you give people a big load of chocolate, it’s possible the stress and expectation of breaking out contributes to actually breaking out. To really get to the bottom of this, you’d have to design a study where people were given disguised chocolate so you could expose them to chocolate without their knowledge and see if they still break out. For example, you could put cocoa powder into opaque capsules, so the participants don’t know if they were getting cocoa or placebo. This would have the additional benefit of eliminating the cocoa butter fat factor. No milk, no sugar, no fat—just pure cocoa powder in capsules versus a placebo. There had never been such a study…until now.

A double-blind, placebo-controlled study assessed the effect of chocolate consumption—actually, cocoa powder consumption—in subjects with a history of acne. Participants were assigned to swallow capsules filled either with unsweetened, 100-percent cocoa or a placebo of an unflavored, unsweetened gelatin powder. Interestingly, “240 capsules were required for 6 oz of [cocoa] powder.” So, what happened? As you can see at 5:50 in my video, researchers found the same significant increase, the same doubling of acne lesions within four days, just like in the Ghirardelli study. So, sadly, it really “appears that in acne-prone…individuals, the consumption of chocolate correlates to an increase in the exacerbation of acne.” 

Now, the study included only men, who don’t have to deal with cyclical hormonal changes like women do, and it’s hard to imagine that after swallowing hundreds of capsules, the real cocoa group didn’t burp up some cocoa taste and realize they were not in the placebo group. But, the best available balance of evidence does suggest that if you’re bothered by acne, you may want to try backing off on chocolate to see if your symptoms improve. 

What about the effects of chocolate, dairy products, and sugar on acne risk? See my video Does Chocolate Cause Acne?.

KEY TAKEAWAYS

  • Although diet was a common adjunct treatment for acne a century ago, studies have been published, purporting to prove that chocolate was not associated with acne. The first was designed misleadingly, pitting a chocolate bar against a fake one composed of 28 percent hydrogenated vegetable oil, a food known to increase inflammatory markers, and another had no control group for comparison. Nevertheless, these two studies, despite major design flaws, effectively dissociated diet from acne in the minds of most dermatologists.
  • Milk chocolate, however, appears to “prime” some pus cells to release extra inflammatory chemicals when exposed to acne-causing bacteria in a petri dish.
  • To investigate whether the chocolate itself is the culprit and not the added sugar or milk, researchers gave subjects milk chocolate or jelly beans. The chocolate group got worse, doubling their acne lesions, while the jelly bean group had no change. So, sugar doesn’t appear to be the culprit.
  • Researchers randomized acne patients to receive white chocolate bars (packed with sugar and milk), dark (100 percent) chocolate bars, or no chocolate bars, and found that acne lesions worsened in the white chocolate group, but not in the dark chocolate or control groups.
  • Other studies did show dark chocolate exacerbating acne, but they lacked a control group, so simply the expectation of experiencing a worsening of acne from consuming chocolate cannot be discounted.
  • In a double-blind, placebo-controlled study, subjects were given capsules filled either with unsweetened, 100-percent cocoa or a placebo of an unflavored, unsweetened gelatin powder. Researchers found the same significant increase in acne lesions, so it appears consumption of chocolate correlates to greater exacerbation of pimples and lesions in those prone to acne.

What effects do cocoa powder and/or chocolate have on other aspects of your health? Check out my other chocolate-covered videos:

You may also be interested in Do Sunflower Seeds Cause Acne?.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Thank You for Your Support

Tue, 12/28/2021 - 07:00

Thanks to your generosity, we have almost hit our goal! Without your support, I wouldn’t be able to spend my days digging into all of the best research and delivering it straight to you. Our number one funding stream is individual contributions from people like you. A huge thank you / gracias / cheers / xièxiè / dankie / merci from all of our staff scattered in seven countries around the globe.

Despite not being able to travel this year due to the challenges brought on by the pandemic, I was heartened to connect with thousands of you through my live webinars and Q&As. Your incredibly generous support of NutritionFacts.org has been a catalyst of inspiration for the enormous undertaking of writing my new book, How Not to Age—one of my largest research projects to date.

This is the 10th anniversary of NutritionFacts.org! My gratitude goes out to everyone who has made this public service possible through your donations, sharing of videos, following on social media, gifting of books, and more. 

Please consider investing in our work by making a tax-deductible donation to NutritionFacts.org, using a credit card or PayPal. You can also transfer stock or mail a check to NutritionFacts.org, PO Box 11400, Takoma Park MD 20913. Federal employees can even donate through the CFC workplace giving program with designation number 26461.

Volunteer Spotlight: Tatiana Fernandez

“I started volunteering at NutritionFacts about five years ago after following Dr. Greger for a while. I thought that the science and the information on NutritionFacts was crucial for helping others and for our own wellbeing. I believe it should be easily accessible globally in every language possible, so I decided to join the Spanish-English Translation Team. I really enjoy being part of the team and have learned so much. Currently, I’m the NutritionFacts YouTube Comments Moderator. I’m still learning a lot and I’m loving it!

Since I was a child, my favorite plant-based meal has been a big, fresh green salad. I literally used to fight with my sister over who got the biggest portion and my mom always got a kick out of the fact that we didn’t fight over candy, we fought over lettuce salad!”

Stay Tuned for the Plant-Based Living Series

Next week we will be launching our new free email series on plant-based living. This 10-week series will include topics like my traffic light system, disease prevention, healthy food swaps, menu planning tools, and more. Keep your eyes out for our Top Ten of 2021 email next week, which will include the series sign-up information. And if you know someone who has been curious about a plant-based diet, invite them to subscribe to the newsletter so they can get the details about this new free program and don’t miss its launch!

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Does Chocolate Cause Acne? 

Thu, 12/23/2021 - 07:00

What are the effects of dairy products, sugar, and chocolate on the formation of pimples?

Acne affects nearly one in ten people globally, “making it the eighth most prevalent disease worldwide.” What is nutrition’s role? If we go back a century, dermatology textbooks “recommended dietary restriction”—for example, advising those with acne to avoid foods like “pork, sausage, cheese, pickles, pastries, large amounts of sweets, cocoa, and chocolate”—but old-timey medicine was full of crackpot theories. Dr. Kellogg, for example, blamed acne on masturbation. (Nothing a few cornflakes couldn’t fix, though!)

Population studies have found associations between acne and the consumption of foods like dairy, sweets, and chocolate. You don’t know if it’s cause and effect, however, until you put it to the test—which they did, as I discuss in my video Does Chocolate Cause Acne?.

There have been high quality reports, like the Harvard Nurses’ Health Study, which looked at nearly 50,000 women, that found a link between acne and the intake of milk, particularly skim milk, during adolescence. This association has been found for teenage boys, as well. Researchers thought the hormones in milk might be responsible, but speculated it could also be the milk protein whey, which is added to skim milk to make it less watery and “might, therefore, play a role” in acne formation or as hormonal carriers. At 1:30 in my video, I discuss a case where whey protein powders were implicated in precipitating acne flares in teens who “had poor response to acne treatment regimens of oral antibiotics, topical retinoids, and benzoyl peroxide.” Their acne just didn’t seem to want to go away—until they stopped the whey supplementation. Could it just be a protein effect, though? It doesn’t seem so since soy protein supplements, for example, did not seem to cause the same problem.

For dairy, in terms of interventional studies, we only have case series, such as the one published in an article titled “Acne and Whey Protein Supplementation Among Bodybuilders.” What happens if you do a systematic review of acne and nutrition? As you can see at 2:02 in my video, out of the 20 or so papers out there on acne and dairy, about three-quarters suggest adverse effects, the remainder report no effect, and no studies suggest a beneficial effect of dairy on acne. You could look at this and conclude a dairy-free diet is worth a try, but this is based on low-grade evidence—that is, Level C and D evidence where Level C is like population studies and Level D is like those series of case reports. What we ideally want are randomized interventional studies, Level A and B evidence. We don’t have them for dairy, but we do have them for chocolate. 

When it comes to acne, no food “is more universally condemned than chocolate.” If you’re the Chocolate Manufacturers Association, which “made possible” the trial we’re discussing, how are you going to design a study to make your product not look so bad? Well, you can always use the drug companies’ old trick of pitting your product against something even worse, which is just what they did. As you can see at 3:01 in my video, researchers fed people chocolate bars versus fake chocolate bars made out of partially hydrogenated vegetable oil—that is, trans fats. The fake chocolate had more sugar and included milk protein, and was 28 percent trans-fat-laden, Crisco-like vegetable shortening. Not surprisingly, subjects got just as many pimples on the fake chocolate bars as the real ones, which allowed the researchers to conclude that eating high amounts of chocolate is a-okay when it comes to acne.

The medical community fell for it. “Have we been guilty of taking candy away from babies?” “Too many patients harbor the delusion that their health can somehow be mysteriously harmed by something in their diet.” The original study’s “finding that chocolate consumption does not exacerbate acne has continued to remain virtually unchallenged for decades and continues to be cited even in…recent review[s].” For example, an article in Pediatric Annals, a pediatrics journal, stated that “years ago [it was] demonstrated that chocolate consumption had no effect on acne…This serves as a cautionary example of how ‘research-based evidence’ should be vigorously scrutinized prior to being incorporated into clinical practice.” Just because something is published in the Journal of the American Medical Association doesn’t necessarily mean it’s a good study, especially when industry interests are involved. 

Maybe we should be telling acne patients to try cutting down not only on the sweets and the dairy, but also the trans fats found in partially hydrogenated vegetable oils. However, we “cannot be unequivocal in [our] advice to acne sufferers” on foods to include or exclude until they’re put to the test in “a well-designed randomized controlled clinical trial.” There simply weren’t any such trials on acne…until now. Stay tuned for my discussion of that in Does Cocoa Powder Cause Acne?.

KEY TAKEAWAYS

  • Acne, the eighth most prevalent disease globally, affects nearly one in ten people.
  • A century ago, acne patients were encouraged to avoid foods like pork, cheese, pastries, and chocolate, and more recent population studies have found acne to be associated with intake of dairy and sweets.
  • The Harvard Nurses’ Health Study found a link between acne and milk consumption, particularly skim milk, during adolescence, an association that has also been found for teen boys.
  • Whey protein powders have been implicated in precipitating acne flares in teens who didn’t respond well to various acne treatment protocols, including oral antibiotics and topical retinoids. However, their acne went away after they stopped whey supplementation, and it was not a protein effect since soy protein supplements didn’t seem to cause the same problem.
  • About three out of four case studies on acne and dairy suggest adverse effects, but the evidence isn’t as strong as it would be from randomized interventional studies.
  • Though there aren’t any randomized interventional studies on dairy and acne, there are for chocolate, thought to be the most universally condemned food when it comes to acne.
  • In a Chocolate Manufacturers Association’s study, researchers designed a misleading trial and gave subjects chocolate bars versus fake ones that were higher in sugar, contained milk protein, and was 28 percent trans-fat-laden with Crisco-like vegetable shortening. Since subjects got as many pimples on the fake chocolate bars as the real ones, researchers concluded that chocolate consumption does not exacerbate acne. Unfortunately, the medical community bought it.

For more on acne, check out:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Dining by Traffic Light: Green Is for Go, Red Is for Stop

Tue, 12/21/2021 - 07:00

In this article, I explain my traffic light system for ranking the relative healthfulness of Green Light vs. Yellow Light vs. Red Light foods.

Whenever I’m asked at a lecture whether a specific food is healthy or not, my reply is: “Compared to what?” For example, are eggs healthy? Compared to some breakfast sausage next to it? Yes. But compared to oatmeal? Not even close. Imagine having $2,000 in your daily calorie bank. How do you want to spend it? For the same number of calories, you can eat either one Big Mac, 50 strawberries, or half a wheelbarrow full of salad greens. Those don’t exactly fill the same culinary niche—if you want a burger, you want a burger—and I don’t expect quarts of strawberries to make it onto the Dollar Menu any time soon, but it’s an illustration of how mountainous a nutritional bang you can get for the same caloric buck.

Every time we put something in our mouth, it’s a lost opportunity to put something even healthier in our mouth. So, what are the best foods to eat and the best foods to avoid? 

I like to think of it in a traffic light system, which I describe in my video Dining by Traffic Light: Green Is for Go, Red Is for Stop, to help quickly identify some of the healthiest options. Green means go, yellow means caution, and red means stop…and think before you put it into your mouth. 

Ideally, on a day-to-day basis, green category foods (unprocessed plant foods) should be maximized, yellow foods (processed plant foods and unprocessed animal foods) minimized, and red category foods (ultra-processed plant foods and processed animal foods) avoided. As far as I can figure, the best available balance of evidence suggests the most healthful diet is one that maximizes the intake of fruits, vegetables, legumes (beans, split peas, chickpeas, and lentils), whole grains, nuts and seeds, mushrooms, and herbs and spices. Real food that grows out of the ground, from fields not factories. These are our most healthful choices. In general, the more whole plant foods and the fewer processed and animal foods, the better. So, I’m talking about more green-light foods and less yellow- and red-light foods. Similar to running red lights in the real world, you may be able to get away with it once and awhile, but I wouldn’t recommend making a habit out of it. 

My traffic light model stresses two important concepts: Plant foods tend to be more healthful than animal foods, in terms of being packed with protective nutrients (such as phytonutrients, antioxidants, potassium, and fiber) and fewer disease-promoting factors (including saturated fat, cholesterol, trans fat, and sodium), and unprocessed foods tend to be more healthful than processed foods. Is that always true? No. Am I saying that all plant foods are better than all animal foods? No. In fact, the worst thing on store shelves has been partially hydrogenated vegetable shortening like Crisco, and that even has “vegetable” right in its name! Even some unprocessed plants, such as blue-green algae, can be toxic, and anyone who has ever had a bad case of poison ivy knows plants don’t always like to be messed with. In general, though, choose plant foods over animal foods, and unprocessed foods over processed. 

What do I mean by processed? The classic example is the milling of grains from whole wheat to white flour. Isn’t it ironic that these grains are then called “refined,” a word that means improved or made more elegant? The elegance was not felt by the millions who died in the 19th century from beriberi, a vitamin B-deficiency disease that resulted from polishing rice from brown to white. White rice is now enriched with vitamins to compensate for the “refinement.” A Nobel Prize was awarded for the discovery of the cause of beriberi and its cure—rice bran, the brown part of rice. Beriberi can cause damage to the heart muscle, resulting in sudden death from heart failure. Surely, such a thing could never happen in modern times, right? An epidemic of heart disease that could be prevented and cured with a change in diet? For more on this, check out my videos on heart disease here.

Sometimes, processing can make foods more healthful. For example, tomato appears to be the one common juice that may actually be more healthful than the whole fruit. The processing of tomato products boosts the availability of its antioxidant red pigment by as much as five-fold. Similarly, the removal of fat from cacao beans to make cocoa powder improves the nutritional profile, since cocoa butter is one of the rare saturated plant fats, along with coconut and palm kernel oils, that may raise cholesterol.

So, for the purposes of the traffic light model, I like to think of “unprocessed” as nothing bad added and nothing good taken away. In the above example, tomato juice could be thought of as relatively unprocessed because even much of the fiber is retained. If salt is added, though, that would make it a processed food in my book and bump it out of the green-light zone. Similarly, I would consider chocolate as a processed food (since it has added sugar), but cocoa powder not. 

The limited role I see for yellow-light foods in a healthy diet is to promote the consumption of green-light foods. Yellow-light foods can be the spoonful of sugar that makes the medicine go down. If the only way I can get a patient to eat oatmeal in the morning is to make it creamy with almond milk, then I tell them to add almond milk. The same could be said for red-light foods. If the only way you’re going to eat a big salad is to sprinkle on something like Bac-Os, then sprinkle away. 

Bac-Os are an example of what I refer to as an ultra-processed food, one that bears no redeeming nutritional qualities or resemblance to anything that grew out of the ground, and often has added badness. Bac-Os has added trans fats, salt, sugar, and even Red 40, a food dye that may cause thousands of thyroid cancers every year. As a red-light food, it should ideally be avoided, but if the alternative to your big spinach salad with something like Bac-Os is KFC, then it’s better to sprinkle on some Bac-Os. The same even goes for real bacon bits. 

I realize some people have religious or ethical objections to even trivial amounts of animal products. Growing up Jewish next to the largest pig factory west of the Mississippi, I can relate to both sentiments. But, from a human health standpoint, when it comes to animal products and processed foods, it’s the overall diet that matters. For example, without hot sauce, my intake of dark green leafy vegetables would plummet. I could try making my own from scratch, of course, but for the time being, the “green” ends justify the “red” means.

On the same note, it’s really the day-to-day that matters most. It shouldn’t make a big difference what we eat on special occasions. Feel free to decorate your birthday cake with edible bacon-flavored candles (I’m not making those up!), though I guess from a food safety point of view, a raw cake batter Salmonella infection could leave you in dire straits. In general, though, it’s really your regular routine that determines your long-term health. Our body has a remarkable ability to recover from sporadic insults, as long as we’re not habitually poking it with a fork. 

That’s why, from a medical standpoint, I don’t like the terms vegetarian and vegan, because they are defined by what you don’t eat. When I taught at Cornell, I had vegan students who appeared to be living off of french fries and beer. Vegan, perhaps, but not terribly health-promoting. That’s why I prefer the term whole food plant-based nutrition. In general, the dividing line between health-promoting foods and disease-promoting foods may be less plant-sourced versus animal-sourced foods, and more whole plant foods versus most everything else.

KEY TAKEAWAYS

  • Every time we eat, we have an opportunity to enjoy something even healthier. I use a traffic light system when I look at food to quickly rank their relative healthfulness: green means go, yellow means caution, and red means stop and think before you put it into your mouth.
  • Green-light foods (unprocessed plant foods) should be maximized, yellow-light foods (processed plant foods and unprocessed animal foods) should be minimized, and we should avoid red-light foods (ultra-processed plant foods and processed animal foods).
  • The best available balance of evidence suggests the most healthful diet maximizes consumption of fruits, vegetables, legumes (beans, split peas, chickpeas, and lentils), whole grains, nuts and seeds, mushrooms, and herbs and spices.
  • Plant foods, which are typically more healthful than animal-based foods, are higher in protective nutrients, such as phytonutrients, antioxidants, potassium, and fiber, and lower in disease-promoting factors, including saturated fat, cholesterol, trans fat, and sodium. And, unprocessed foods tend to be more healthful than processed foods.
  • The classic example is a processed food is the milling of grains from whole wheat to white flour.
  • Processing doesn’t always lower the healthfulness of a food. For instance, tomato appears to be the one common juice that may be more healthful than the whole fruit because the processing of tomato products boosts the availability of its antioxidant red pigment by as much as five-fold.
  • In terms of my traffic light system, I think of “unprocessed” as nothing bad added and nothing good taken away.
  • There is a role for yellow-light foods, albeit a limited one—to promote the consumption of green-light foods. For example, if adding a yellow-light food to a green-light food is the only way you will eat it, then it’s worthwhile. Add almond milk to oatmeal, for example, if plain oatmeal isn’t creamy enough for you to eat it.
  • Ultra-processed foods have no redeeming nutritional qualities, don’t resemble anything that grew out of the ground, and often have added badness—e.g., Bac-Os, with their added trans fats, salt, sugar, and even Red 40, a food dye that may cause thousands of thyroid cancers every year. As a red-light food, it should ideally be avoided, but if the alternative to a spinach salad with Bac-Os is KFC, then sprinkle on some Bac-Os to avoid the even worse red-light meal.
  • Your regular routine determines your long-term health, so don’t place great significance on a special occasion meal here or there. Our body has a remarkable ability to recover from sporadic insults—just don’t constantly, habitually assault it with a fork.
  • I prefer the term “whole food, plant-based nutrition” to “vegetarian” or “vegan” because you can be veg*n without being health-promoting in your diet.
  • Generally speaking, the line in the same between health-promoting foods and disease-promoting foods may be less plant-sourced versus animal-sourced foods, and more whole plant foods versus most everything else.

This is one of those rare blogs I’ve done that’s not just straight peer-reviewed science. If you’re looking for more of this type of analysis, look no further than How Not to Die—more specifically, the whole second half of my book, which contains exactly that. Note that all of the recipes from its companion, The How Not to Die Cookbook, are comprised of 100 percent Green Light ingredients. How do you make something taste salty without salt? Sweet without sugar? Check out my cookbook and see—and then taste—for yourself! (All proceeds I receive from all my books are donated to charity.) 

I explore another one of the tools I introduced in the book in my video Dr. Greger’s Daily Dozen Checklist.

Let me know if you like these more practical tips-type blogs, or if you’d rather I just stick to the science.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Support NutritionFacts.org — Fill the Carrot

Thu, 12/16/2021 - 07:00

Today is the start of our annual end-of-year fundraising drive. More than half of our entire annual operating budget is raised around these final few weeks of the year, and our goal is to raise $350,000. We count on your giving-season generosity to make a tax-deductible donation to keep NutritionFacts.org going and growing.

This year is the tenth anniversary of NutritionFacts.org. Before the organization was founded, I traveled around the country giving hundreds of presentations about lifestyle medicine each year. Then, the Jesse & Julie Rasch Foundation generously provided the seed money to launch the organization and website in order to reach even more people with this life-changing, life-saving information. Now, we rely on the support of individual donors like you. 

A lot has changed in the last ten years. Today, more than a dozen staff members keep the engines running. Just this past year, we hired four new positions to help expand our outreach and web development programs. 

This is all thanks to the support of our donors. As you know, there are no ads or corporate sponsors on NutritionFacts.org. Our supporters are truly the lifeblood of this organization. You enable us to do this work. Every year, thousands of people step forward and make donations large and small to express appreciation for our work. Hundreds have even signed up to be monthly donors, which helps ensure a predictable and steady stream of support. 

Please “root” for the facts by helping us fill the carrot during our year-end funding drive! It’s a numbers game; even a single dollar can help.

For the second year in a row, a generous donor is providing a $100,000 match. Make your contributions early to have them doubled! 

On the Donate Page, you can make a tax-deductible donation using a credit card or PayPal. You can also transfer stock or mail a check to NutritionFacts.org, PO Box 11400, Takoma Park, MD 20913. Federal employees can even donate through the CFC workplace giving program with designation number 26461.

 

Your Donations Help Change Lives

“I was raised on the standard American diet, and by the time I was approaching 40, I hit my highest weight at 240. I can still remember that day. It’s when I’d had enough. I started to research nutrition, and your site was the first I came across. It changed my life. I have two young children, and I want to be around for them as long as I can without being a burden either. I lost my Mom at 43 and my Dad at 65, and I don’t want my kids to experience what I did. I also want to set a good example for them.

Now, at nearly 49 years old, I feel and look better than I have at any point in my life. People think I’m around 35. I can hike and bike for miles on end, run football routes with my 9-year-old son, and play basketball with him and his friends. When I was at my heaviest, my doctor wanted to put me on a statin; dietary changes were never mentioned. But, I wanted to fix it myself. My doctor now calls my lipid profile and blood work ‘remarkable.’ Learning about nutrition, calorie density, and plant-based diets is the single greatest self improvement I’ve ever done. And I thank you and all of your colleagues for the information to help me succeed. Hopefully I can influence the people around me, too!” –Jack

 

Key Takeaways: Cocoa

Although we should avoid processed chocolate due to the sugar content, cocoa has a number of health benefits. What are they? Find out on the topic page.

 

 

 

Recipe: Champurrado

Now that you know about the benefits of cocoa, try our recipe for this traditional Mexican drink. Get the free recipe here, and see how it’s made on our Instagram

 

 

 

Books Available Around the World

Still looking for holiday gifts? My books are available in several countries. In fact, the paperback version of The How Not to Diet Cookbook was just published in the United Kingdom! Check out our help center article to see where and how to purchase my books globally. And, as always, all proceeds from my books are donated to charity.

 

 

 

 

Extra Virgin Olive Oil for Arthritis – What happened when topical olive oil was pitted against an ibuprofen-type drug for osteoarthritis and rheumatoid arthritis?

 

 

Are Onions Beneficial for Testosterone, Osteoporosis, Allergies, and Cancer? – What did randomized controlled human trials find about the ways we may—or may not—benefit from eating onions?

 

 

Are Baruka Nuts the Healthiest Nut?  – How do barukas, also known as baru almonds, compare with other nuts?

 

 

 

Live Q&As 

Due to my writing schedule for my next book, How Not to Age, I will be taking a break from Q&As until summer 2022. In the meantime, you can find links to past live Q&As here on NutritionFacts.org. And, remember, I have an audio podcast to keep you company, too.

 

 

 

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How to Balance the Risks and Benefits of Mammograms

Tue, 12/14/2021 - 07:00

Fact boxes can quantify benefits and harms in a clear and accessible format. 

When it comes to cancer screening, doctors “have too often ignored” the fact that women may place different weights on various pros and cons, so they have just “focused on persuading rather than educating” and letting people make up their own mind. To do that though, “they need some quantification of its benefits and harms” in a clear and accessible format. Enter, “fact boxes.”

Let’s consider an example: In 2014, German physicians recommended transvaginal ultrasounds, in which a probe is inserted to look around, to millions of women to screen for ovarian cancer. Is that effective? What does the science say? Based on a study of hundreds of thousands of women, if you randomize a thousand women to get vaginal ultrasounds and a thousand women to skip the screening, and then follow them out for a decade or so, three of the women who did not get screened will die from ovarian cancer, as will the same number of women who did get screened. So, there was no benefit at all. Instead, 32 of the women who had gotten screened went into surgery, some to have their ovaries removed, because something looked suspicious on the ultrasound, but it turned out to be totally unnecessary. And, one of those women suffered surgical complications—all for naught. Just harms, no benefits, yet millions of women were subjected to the probing, “probably resulting in more than 10 000 women having healthy ovaries removed in just one year.” A boon for the hospitals and the surgeons (and their local BMW dealers), but just pain and suffering for the women.

What would a fact box for mammograms look like? I show one at 1:44 in my video The Pros and Cons of Mammograms. As you can see, each grey circle in the graphic represents one woman. A thousand women were either randomized to skip mammograms or randomized to get screened. After a decade, about five out of the thousand women in the no-screening group will die from breast cancer. So, even without mammography screening, the chances of dying from breast cancer in one’s fifties is less than 1 percent. But, by getting regular mammograms, instead of five out of a thousand women dying from breast cancer, only four in a thousand will die from breast cancer, though the number of women dying overall appears to be the same with or without screening. So, no lives are necessarily saved overall. But, maybe the studies just haven’t had the statistical power to pick up on an overall survival benefit. 

In terms of harms, however, a hundred of the women getting mammograms will be called back for false alarms and maybe even get biopsied, and five will have unnecessary lumpectomies or mastectomies. “A third potential harm, getting radiation-induced breast cancer from the mammography, is not included because only rough indirect estimates (1–5 in 10,000) exist.” 

I show a graphical representation of another study at 2:51 in my video. Researchers looked at 20 years of data from women following the current U.S. Preventive Services Task Force recommendations to get screened every other year starting at age 50. One would expect 200 false alarms over those two decades, but only about 30 would end up getting biopsied. A few cancers would be missed, but, in 15 cases, too many would be found, meaning women would be diagnosed with—and treated for—breast cancer unnecessarily. On the other hand, two breast cancer deaths would be averted, thanks to mammograms, though no overall lives would apparently be saved. 

Not everyone agrees with these numbers, though. At 3:28 in my video, I show the most optimistic numbers I could find per 1,000 women screened. As you can see, there may be up to ten times the benefit for a woman getting mammograms every year for 25 years starting at age 40. This is at the cost of an average of three false alarms for each woman, a one in three chance of getting a biopsy, and about a 1 percent chance of being diagnosed and treated for breast cancer unnecessarily. 

Now, this assumes we’re talking about asymptomatic women at average risk. Women at higher risk, such as those who have already had breast cancer or have BRCA gene mutations, would be expected to benefit much more. For the average woman, though, “there is simply no ‘right’ answer to whether a woman should undergo mammographic screening.” It should be left up to each woman to make up her own mind. 

“We hope that [presenting these] data are sufficient for some women to make the decision about whether or not to be screened. Some may choose to pursue screening, valuing any potential for benefit as warranting the accompanying harms. Others may choose not to,” feeling the potential “harms as being too great to justify pursuing the relatively small benefit.” 

Regardless, how about trying not to get breast cancer in the first place? “Individuals would rather be told to get a quick test every few years than be told to eat well and exercise to prevent cancer [before it starts]. ‘Screening has become an easy way for both doctor and patient to think they are doing something good for their health, but their risk of cancer hasn’t changed at all.’” Indeed, getting screened for cancer doesn’t change their risk of getting cancer in the first place—and this doesn’t apply only to cancer. The same diet and lifestyle that can protect against cancer can also protect against the leading killer of women. As you can see at 4:56 in my video, for example, the annual number of women who died from breast cancer from 2006 to 2010 was under 50,000, while the annual number of women who died from heart disease during that period was over 400,000. And while mammograms may not save lives, we know that lifestyle modifications to prevent heart disease can. So maybe some of those billions of dollars spent every year on mammogram programs could be better spent saving the lives of women.

KEY TAKEAWAYS

  • Without mammography screening, the chances of dying from breast cancer when in your fifties is less than 1 percent. With regular mammograms, instead of about five out of a thousand women dying from breast cancer, four women will.
  • There are myriad harms associated with mammograms, though, including false alarms and overdiagnosis, which can result in biopsies, unnecessary lumpectomies or mastectomies, radiation treatment, and chemotherapy, not to mention radiation-induced breast cancer from mammography and the stress and emotional toll of it all.
  • Even looking at the most optimistic numbers per thousand women screened, which shows there may be up to ten times the benefit for a woman getting annual mammograms for 25 years starting at age 40, that is at the cost of an average of three false alarms for each woman, a one in three chance of getting a biopsy, and about a 1 percent chance of being diagnosed and treated for breast cancer unnecessarily.
  • The hope is for women to be presented with all the data to be able to make informed decisions about whether or not to be screened.
  • Screening has become a replacement for trying to prevent cancer through lifestyle efforts, such as eating well and exercising, because it can be thought of as actively doing something positive for their health despite not changing risk of cancer at all.
  • The same diet and lifestyle—one based on whole plant foods—that can be protective against cancer may also protect against heart disease, the leading killer of women.

There is just so much confusion when it comes to mammography, combined with the corrupting commercial interests of a billion-dollar industry. As with any important health decision, everyone should be fully informed of the risks and benefits, and make up their own mind about their own bodies. This is the final installment in my 14-part series on mammograms, which includes: 

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I’ve produced so many videos on diet and lifestyle approaches to preventing and treating breast cancer. Just search for them on the site, and all will be revealed.

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Doctors Tested for Basic Understanding of Mammogram Math

Thu, 12/09/2021 - 07:00

If doctors don’t understand health statistics, how can they possibly properly counsel patients? 

“In these mammography wars, rational thinking can be easily lost.” Mammograms are big business, bringing in about seven billion dollars a year, but it would be a bit too “cynical to believe” that the pushback from mammogram critics “stems only from self-interest of radiologists, surgeons, managers, and so on, whose daily bread depends on the continuation of mammographic screening programmes.” It just makes intuitive sense that mammograms should work, but that’s why we have science—so we can put things to the test. “We owe it to [our patients] to be ‘evidence-based’ rather than ‘faith-based.’” They deserve an objective analysis of the data. 

“We have done a dismal job of accurately informing the public about screening.” Why? One reason is that the doctors themselves aren’t informed, as I discuss in my video Why Patients Aren’t Informed About Mammograms. A survey of radiologists found that 96 percent overestimated a middle-aged woman’s risk of breast cancer, for example. In one sneaky study, researchers “contacted gynecologists’ practices and made an appointment for telephone counseling.” During the actual phone consultation, they pretended to be a concerned family member, asking about the benefits and harms of mammograms. “Although all gynecologists appeared motivated and concerned with sufficiently answering our questions, they lacked information as well as knowledge of how to communicate information on medical risk.” 

In an article titled “When Doctors Meet Numbers,” the authors write that “we cannot take for granted the ability of physicians to understand and interpret quantitative information and to use it to the best advantage of the patient.” In fact, this is “an educational blind spot” for physicians that was identified more than 80 years ago. In one study, for example, 151 practicing physicians were asked a series of multiple choice and true-or-false questions to gauge their practical understanding of some key concepts. They failed miserably, getting just 55 percent correct, which is only about 20 percent more than they would have gotten right just by guessing randomly.

If doctors don’t understand health statistics, how can they possibly counsel patients properly? In a famous study, one hundred physicians were asked what the chances were of a woman actually having breast cancer if her mammogram came back positive. They were given all the numerical data so they could do the math, but 95 out of 100 not only answered incorrectly, but they were spectacularly wrong—as in off by 1000 percent.

Even doctors at Harvard had a problem. Faculty, staff, and students at Harvard Medical School were asked a simple question, and 82 percent got it wrong. That was a few decades ago, though. What happened in an updated survey in Boston? Only 77 percent got it wrong, but they were off by an average of about 3000 percent, demonstrating medicine’s continued “uncomfortable relationship with math.”

“Only 12% of the 4713 surveyed obstetrics-gynecology residents were able to correctly answer 2 simple questions on medical statistics…What will the uninformed 88% of these residents say when their first patient asks about her chance of truly having breast cancer given a positive mammogram?” What’s particularly frightening is that, in some studies, those doctors “most confident in their estimates were furthest away from the correct response.” They didn’t even know that they didn’t know. “All of these studies document the same phenomenon: A considerable number of physicians are statistically illiterate, that is, they do not understand the statistics of their own discipline.” 

So, when physicians say they don’t have time to fully inform patients about the benefits and harms of a test, maybe that’s a good thing if they don’t even know what they’re talking about. Instead, they may just talk about the benefits of breast cancer screening and skip “any discussion of adverse effects.” Given all of this, we shouldn’t be surprised when nine out of ten women “believed that this screening could not harm a woman without breast cancer,” while often greatly overestimating the benefits. “In fact, the benefits and harms are so evenly balanced” that perhaps we should just inform women and let them make up their own minds. That’s not what you hear from advertising campaigns, though. An ad “simply tells women to be screened, overstates the benefit of mammography, and ignores harms altogether.” Indeed, instead of education, an “obvious approach was to use powerful tools of persuasion—including fear, guilt, and a sense of personal responsibility—to convince people to get screened.” Whatever it takes. 

It’s “easy to ‘sell’ screening: just magnify the benefit, minimize the cost, and keep the numbers less than transparent.” To put routine screenings to the test, studies have randomized hundreds of thousands of women to get mammograms or not, but what’s the point if we’re not going to share the results? “We spend billions on clinical studies but fail to ensure that patients and physicians are communicated the results transparently.” Maybe women should “tear up the pink ribbons and campaign for honest information.” How else can women make informed decisions? Instead, hospitals throw “monthly ‘mingle and mammograms’ parties.” In addition to “appetizers, foot massages, and bags emblazoned with the logo ‘fight like a girl,’” maybe they should “serve[ ] women balanced information about the benefits and harms of screening to chew on.

Unfortunately, many doctors display a similar ignorance about nutrition. See, for example, Physicians May Be Missing Their Most Important Tool.

KEY TAKEAWAYS

  • Mammography screening brings in about seven billion dollars a year, and the industry suffers from conflicts of interest amongst radiologist, surgeons, and others who may profit off of the procedure.
  • One reason the medical community has failed to accurately inform the public about screening is that physicians themselves aren’t informed. A survey of radiologists found that 96 percent overestimated a middle-aged woman’s break cancer risk, for example.
  • An “educational blind spot” for doctors was identified more than eight decades ago—namely, physicians may not understand and interpret quantitative data, nor be able to use the information to the patient’s advantage.
  • In a famous study, a hundred physicians were asked what a woman’s chance of having breast cancer would be with a positive mammogram result, and 95 out of the 100 doctors not only answered incorrectly, but were off by 1,000 percent.
  • Study after study, including those with physicians at the esteemed Harvard University, show a significant number of doctors are “statistically illiterate, that is, they do not understand the statistics of their own discipline.”
  • It follows that, instead of fully informing patients about the benefits and harms of a screening test, physicians may omit discussion of risks and only present the benefits. As such, it is understandable that nine out of ten women believe mammograms could not be harmful to a woman without breast cancer.
  • The benefits and harms of mammograms, however, are evenly balanced.
  • Women deserve to know the benefits and harms of screening to make informed decisions about whether the risk is worth it.

There is so much confusion when it comes to mammography, combined with the corrupting commercial interests of a billion-dollar industry. As with any important health decision, everyone should be fully informed of the risks and benefits, and make up their own mind about their own bodies. This is one installment in my 14-part series on mammograms, which includes: 

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Breast Cancer Can Grow and Spread for Decades Before “Early” Detection

Tue, 12/07/2021 - 07:00

“Early” detection is actually really late. Without mammograms, breast cancer may not be caught for an average of 22.8 years. With mammograms, though, breast cancer may only grow and spread for…21.4 years.

Critics of breast cancer screening claim that, on a population scale, mammograms have never been shown to actually prolong women’s lives on average. But, as you can see at 0:16 in my video Why Mammograms Don’t Appear to Save Lives, there was a clear drop in breast cancer mortality in both the UK and Denmark right when routine mammograms were introduced.

That didn’t appear to be the case in Switzerland, though, where breast cancer mortality had been declining for years before routine mammograms were introduced, so let’s go back and explore what happened in the UK. “It is tempting to conclude that breast screening was causal”—that is, caused the drop in mortality—but it’s a little suspicious that the drop happened immediately. You’d expect it to take a few years to manifest.

What’s more, if you split up the UK data by age group, the whole thing falls apart. At 0:54 in my video, I show a graph that illustrates how the numbers play out—rates of breast cancer mortality by age group over the years. Women in the 50 to 64 age group were the only ones who started screening around the same time, but there were mortality drops in other age groups of women who were not getting mammograms. This was true for the Denmark data as well. They had the same drop in breast cancer mortality with or without screening. What’s going on? 

As you can see at 1:22 in my video, the US data are similar to the UK’s. The United States experienced a beautiful drop in breast cancer mortality right when mass mammograms were introduced around 1990. We saw an even more dramatic drop, however, among women getting less screening, and an even greater drop in breast cancer mortality among women not getting mammograms at all. “In other words, there was a larger relative reduction in mortality among women who were not exposed to screening mammography than among those who were exposed.” What happened? The decrease in mortality “must largely be the result of improved treatment, not screening.” 

Breast cancer mortality started dropping all around the world at the same time, regardless of when mammogram screening started, as you can see at 1:59 in my video. There was “no relation at all between start of screening and the reduction in breast cancer mortality.” “The declines…are more likely explained by the introduction of tamoxifen,” an estrogen-blocking drug. As you can see at 2:15 in my video, breast cancer death rates clearly plummeted in the United States after the Food and Drug Administration approved tamoxifen in 1990.

This doesn’t mean breast cancer screening isn’t playing a role, though. In fact, randomized controlled trials have shown that routine mammograms may reduce breast cancer mortality by 20 percent. Now, that 20 percent drop represents the change from about five in a thousand women dying from breast cancer without screening during that time down to four in a thousand women dying with screening. So, the risk of dying for women who are invited for routine screening is practically the same as the risk of dying for women who are not getting mammograms. What’s more, this is assuming mammograms don’t increase deaths from other causes. In fact, “[i]f we take into account the cardiac and lung cancer deaths caused by radiotherapy,” the radiation treatments given to women who are overdiagnosed with pseudo disease and unnecessarily treated for cancer, thanks to mammography, “there appears to be no mortality benefit.”

Why aren’t mammograms more effective? It seems so simple. Just catch the disease early, right? It turns out that by the time breast cancer is caught by mammograms, it may have already been growing for decades. “It is therefore misleading to say that cancers are caught ‘early’ with screening. They are caught very late…” Without mammograms, breast cancer may not be caught for 22.8 years. With mammograms, however, breast cancer may grow and spread for 21.4 years. It’s not surprising that mammograms don’t do a better job at preventing breast cancer deaths since the cancer can spread before you can even cut it out. Concerns have even been raised that the trauma from surgery may accelerate the growth of any cancer left behind, which may would help explain why there isn’t more benefit to screening. 

Regardless, nine out of ten women may still be in the dark, “overestimating the mortality reduction from mammography screening by at least one order of magnitude,” by ten-fold or more. About the same percentage of men thought similarly about prostate cancer screening, vastly overestimating the benefits or simply not knowing. Only 1.5 percent of women surveyed were in the ballpark, choosing “the best estimate for reduction in mortality due to breast cancer screening.” Ironically, those who reported “frequent consulting of physicians” and reading health pamphlets did even worse, overestimating the benefits of screening programs even more. 

Decades ago, a director of a mammogram project, realizing even back then that routine mammograms may not actually be saving women’s lives, asked as she lay on her death bed before succumbing to breast cancer herself, “Are we brainwashing ourselves into thinking that we are making a dramatic impact on a serious disease before we brainwash the public?”

KEY TAKEAWAYS

  • There appeared to be a drop in breast cancer mortality in the UK and Denmark when routine mammograms were introduced, but not in Switzerland. A closer look at the UK and Denmark data shows that there were mortality drops in age groups of women not getting mammograms, as only those in the 50 to 64 age group began getting screened.
  • Similarly, the United States experienced a drop in breast cancer mortality right when widespread mammograms were introduced, but a more dramatic drop was found in women getting less screening and an even larger drop was seen in breast cancer mortality among those not getting mammograms at all.
  • Breast cancer mortality began dropping around the world at the same time, regardless of when mammography screening began, thought likely due to the introduction of tamoxifen, an estrogen-blocking drug.
  • Randomized controlled trials have found that routine mammograms may reduce mortality from about five in a thousand dying from breast cancer without screening down to four in a thousand, so risk of death for women invited for routine screening is almost the same as for those not getting mammograms.
  • When cardiac and lung cancer deaths caused by radiation treatments given to women who had been overdiagnosed with pseudo-disease and unnecessarily treated for cancer, as a result of mammography, there appears to be no mortality benefit at all.
  • By the time breast cancer is caught by mammograms, they may have been growing for decades. Without mammograms, breast cancer may not be caught for 22.8 years. With mammograms, however, breast cancer may grow and spread for 21.4 years, nearly the same amount of time.
  • Nine out of ten women may still be unaware, overestimating the mortality reduction from mammograms by ten-fold or more, a percentage also seen in men who think similarly about prostate cancer screening.

Because “early” detection is actually really late, we can’t wait for a diagnosis to start eating more healthfully. Get going with these videos and tips: 

There is so much confusion when it comes to mammography, combined with the corrupting commercial interests of a billion-dollar industry. As with any important health decision, everyone should be fully informed of the risks and benefits, and make up their own mind about their own bodies. This is one installment in my 14-part series on mammograms, which includes: 

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Learn More Than 97% of Doctors About Lead-Time Bias

Thu, 12/02/2021 - 07:00

After reading this, you’ll know more than an estimated 97 percent of doctors about a critical concept called lead-time bias. 

While running for president of the United States, former New York mayor Rudy Giuliani ran a campaign ad contrasting his 82 percent chance of surviving prostate cancer in the United States with the 44 percent chance of surviving it in England “under socialized medicine” where routine PSA testing for prostate cancer is not done. “To Giuliani this meant that he was lucky to be living in New York and not in York, because his chances of surviving prostate cancer seemed to be twice as high in New York. Yet despite this impressive difference in the five year survival rate, the mortality rate”—the rate at which men were dying of prostate cancer—“was about the same in the US and the UK.” How could that be? PSA testing increased survival from 44 to 82 percent, so how is that “not evidence that screening saves lives? For two reasons: The first is lead time bias…The second is overdiagnosis.” 

As I illustrate at 1:05 in my video Breast Cancer and the Five Year Survival Rate Myth, overdiagnosis is when a cancer that otherwise would have never caused a problem is detected. Consider this: Let’s say that, without screening, only 400 people out of a thousand with progressive cancer are alive five years later. That means that without screening, the five-year survival rate is only 40 percent. But, let’s say that with screening, an additional two thousand cancers are overdiagnosed, meaning cancers that would have never caused a problem or may have disappeared on their own are picked up. So, because those cancers are harmless, those overdiagnosed patients all still alive five years later, assuming their unnecessary cancer treatment didn’t kill them. In this way, the five-year survival rate has just doubled, even though in either case, the same number of people died from cancer. If that’s confusing, watch the video. That’s one way the changes in survival rates with screening may not correlate with changes in actual cancer death rates. 

The other way is lead time bias. Imagine a group of patients who were diagnosed with cancer because of symptoms at age 67 and all died at age 70. Each patient survived only three years. So, the five-year survival rate for the group is 0 percent. Now, imagine that the same group underwent screening. By definition, screening tests lead to earlier diagnosis. Suppose that with screening, the cancers were diagnosed in all patients at age 60 instead of 67, but, nevertheless, they all still died at age 70. In this screening scenario, each patient survived ten years, which makes the five-year survival rate for this group 100 percent. Survival just went from 0 to 100 percent! You can imagine the headlines: “ Cancer patients live three times longer with new screening test, ten years instead of three.” All that really happened in this screening scenario, though, is that the people were treated as cancer patients for an additional seven years. If anything, that would likely just diminish their quality of life. 

So, that’s the second way that changes in survival rates with screening may not correlate with changes in actual cancer death rates. In fact, the correlation is zero, as you can see at 3:14 in my video. There is no correlation at all between increases in survival rates and decreases in mortality rates. That’s why “[i]f there were an Oscar for misleading statistics, using survival statistics to judge the benefit of screening would win a lifetime achievement award hands down. There is no way to disentangle lead time and overdiagnosis biases from screening survival data.” That’s why, “in the context of screening, these statistics are meaningless: there is no correlation between changes in survival and what really matters, changes in how many people die.” Yet, that’s what you see in the ads and leaflets from most of the cancer charities and what you hear from the government. Even prestigious cancer centers, like M.D. Anderson, have tried to hoodwink the public this way, as you can see at 3:57 in my video.

If you’ve never heard of lead time bias, don’t worry, you’re not alone. Your doctor may not have heard of it either. “Fifty-four of the 65 physicians [surveyed] did not know what the lead-time bias was. Of the remaining 11 physicians who indicated they did know, only 2 explained the bias correctly.” So, just by having read to this point in this blog post, you may already know more about this than 97 percent of doctors. 

To be fair, though, is it possible the doctors don’t recognize the term but understand the concept? No. “The majority of primary care physicians did not know which screening statistics provide reliable evidence on whether screening works.” In fact, they “were also 3 times more likely to say they would ‘definitely recommend’ a [cancer screening] test” based on “irrelevant evidence,” compared to a test that actually decreased cancer mortality by 20 percent. 

If physicians don’t even understand key cancer statistics, how are they going to effectively counsel their patients? “Statistically illiterate physicians are doomed to rely on their statistically illiterate conclusions, on local custom, and on the (mostly) inaccurate promises of pharmaceutical sales representatives and their leaflets.” 

KEY TAKEAWAYS

  • Overdiagnosis, the detection of cancer that otherwise would never have caused a problem, can result in unnecessary cancer treatments and affect survival rates of breast cancer patients.
  • For example, without screening, the five-year survival rate is 40 percent. With screening, however, overdiagnosis results in more cancer patients, despite the likelihood that their cancers are harmless or may disappear on their own. And, those overdiagnosed patients should be alive after five years, which doubles the five-year survival rate, even though the same number of patients died from cancer.
  • Lead time bias is also an issue. Symptomatic patients may be diagnosed at a later age than had they been with screening, which, by definition, leads to earlier diagnosis. In this case, imagine patients were diagnosed without screening at age 67 and died three years later, so the five-year survival rate is 0 percent. Now imagine the group underwent screening and the cancers were diagnosed at age 60, so they were alive for ten years before dying at 70. In the screening scenario, the five-year survival rate for the group is 100 percent.
  • In fact, there is no correlation between increases in survival rates and decreases in mortality rates.
  • It is not possible to disentangle the biases of lead time and overdiagnosis from screening survival data.
  • The overwhelming majority of doctors—54 out of 65 physicians surveyed—are unfamiliar with lead time bias, and of the 11 who indicated they did know, only 2 explained the bias accurately.
  • How can doctors who don’t even understand key cancer statistics effectively counsel their patients?

There is just so much confusion when it comes to mammography, combined with the corrupting commercial interests of a billion-dollar industry. As with any important health decision, everyone should be fully informed of the risks and benefits, and make up their own mind about their own bodies. This is one installment in my 14-part series on mammograms, which includes:

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Does Laptop Wi-Fi Affect Fertility?

Tue, 11/30/2021 - 07:00

Should laptops not be on laps? What is the effect of WiFi exposure on sperm motility and DNA damage?

“It is impossible to imagine a modern socially-active man who does not use mobile devices and/or computers with Wi-Fi function.” Might cell phones or wireless internet be harmful for male fertility? You may recall that I’ve previously discussed how the sperm of men who use Wi-Fi tend not to get along as swimmingly, but that was an observational study. You don’t really know if Wi-Fi actually damages sperm until you put it to the test, the topic of my video Does Laptop Wi-Fi Lower Sperm Counts?.

The title “Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation” kind of gives it all away. That was “the first study to evaluate the direct impact of laptop use on human spermatozoa.” As you can see at 0:43 in my video, the data from human sperm DNA fragmentation levels in samples placed near and far away from a laptop with an active Wi-Fi connection suggest that one might not want to position a Wi-Fi device near the male reproductive organs as that “may decrease human sperm quality.”

Indeed, Wi-Fi exposure may decrease human sperm motility and increase sperm DNA fragmentation, but the effect is minor. Is a 10 percent decrease in “progressive motile” sperm really going to make a difference? Fertile men release hundreds of millions. What has yet to be done is a study looking at bouncing baby endpoints. Do men randomized to a certain WiFi exposure have a tougher time having children? It’s actually a harder study to perform than one might think. You can’t just have men avoid cell phones and laptops for a day. Yes, we make millions of new sperm a day, but they take months to mature. The sperm with which you conceive today started as a preconceived notion months before. So, you can imagine why such a study has yet to be done. You’d have to randomize men to essentially avoid wireless communications completely, or maybe come up with some kind of Faraday cage underwear.

Another reason one may not want to use a laptop computer on their lap is that the heat generated by the laptop, with Wi-Fi or not, “can warm men’s scrotums,” undermining the whole point of scrotum possession in the first place—namely, to contain the male gonads in such a way as “to allow the testes and epididymis to be exposed to a temperature a few degrees below that of core body temperature.” This all dates back to a famous series of experiments conducted in 1968. 

It was an illuminating study, one might say, as the subjects’ “scrota were heated with a 150-watt electric light bulb…In some of the trials, the heat from the 150-watt bulb was increased by the use of an ordinary reflector, although the bulb alone was just as effective if placed somewhat nearer the skin. This was simpler, but was more likely to cause accidental burning by contact.” (Why can’t I seem to get Jerry Lee Lewis’ “Great Balls of Fire” out of my head?)

Now, we have nice, cool fluorescents instead of 150-watt bulbs, but heated car seats remain a “testicular heat stress factor.” Saunas aren’t a good idea for men trying to conceive. At 2:52 in my video, I show a chart of sperm counts before and after sauna exposure. Sauna exposure apparently cuts sperm production in half, and the sperm count was still down three months later. There was an apparent full recovery by six months, though. This is why you may want to go with boxers, not briefs, or even go commando. Who makes money on going au naturel, though? Enter the “scrotal cooling” industry, though a review noted that “more acceptable scrotal cooling technique” really needs to be developed. Why? Whatever are the researchers referring to?

It seems the “devices used to achieve testicular cooling” currently on the market are “not practical for day-to-day use. One device was a curved ice rubber collar filled with ice cubes,” and another was similar to a freezer gel pack “inserted in the participants’ underwear every night,” but don’t worry because it thaws in three to four hours, “resulting in a cooling effect.” Holy snowballs, Batman!

Do not, I repeat, do not put an ice pack on your scrotum. A few frozen peas and carrots in a strategically placed surgical glove can give you frostbite. (Maybe the one time vegetables can be bad for you!) Then, there’s the schvitzer, “a cotton suspensory bandage that releases fluid (water or alcohol) to keep the scrotum damp,” and, finally, a device attached with a belt that “achieve[s] scrotal cooling” with a continuous air stream. 

With so many options to choose from, do laptop users really need protection from scrotal hyperthermia? You don’t know…until you put it to the test. Indeed, an increase in scrotal temperature was found in laptop computer users, scrotal temperatures up a feverish 5∞ Fahrenheit. 

A little scrotal warmth didn’t sound that bad until I read this case report: A previously healthy 50-year-old scientist typed out a report one evening, sitting comfortably in his favorite chair with laptop on lap, but awoke the next day with “penile and scrotal blisters” that then “broke and developed into infected wounds that caused extensive suppuration,” that is, oozing pus. 

Even third-degree burns have been reported, requiring surgical intervention with skin grafts. In one report, a man drank 12 units of vodka and passed out while watching a film on his laptop, which was resting on his bare thighs. The laptop burned his leg. The surgeons called for a “public education campaign” to “educate the public against the risks of using a laptop in its most literal sense.” That’s one approach, but why not educate the public instead against drinking 12 units of vodka?

KEY TAKEAWAYS

  • Researchers suggest positioning Wi-Fi devices away from male reproductive organizes as Wi-Fi exposure may decrease the quality of the sperm—decreasing its motility and increasing its DNA fragmentation.
  • Heat generated by a laptop, with or without Wi-Fi capability, is another reason not to place the device on the lap, as it can warm men’s scrotums. This undermines its functional purpose—that is, to contain the male gonads such that the testes and epididymis can be exposed to a temperature a few degrees lower than core body temperature.
  • Similarly, heated car seats can warm testes and sauna exposure has been found to cut sperm production in half, though there was full recovery by six months.
  • The “scrotal cooling” industry has emerged with devices intended to “achieve testicular cooling,” such as a rubber collars to be filled with ice cubes and freezer gel packs.
  • Among laptop computer users, scrotal temperatures were found to be elevated by 5°F, which seems insignificant. However, in one case report, a previously healthy middle-aged man typed out a report with his laptop on his lap and awake the next day with blisters on his penis and scrotum that broke and oozed pus.
  • In fact, even third-degree burns have been reported with laptop-on-the-lap use, requiring surgeries with skin grafts.

This may not just be an issue for men, as I described in my video Do Cell Phones Lower Sperm Counts? and Flashback Friday: Do Cell Phones Lower Sperm Counts? & Does Laptop WiFi Lower Sperm Counts?

For more on brain issues, check out:

I cover male fertility in videos such as:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

 

Free Recipe for a Great Fall Meal and New Volume of Videos

Thu, 11/25/2021 - 07:00

My new volume of videos—the 56th, if you can believe it!—is out now. In it, I discuss leaky gut, inflammation, the potato series I presented in a webinar a few months ago, and more. It is available as a streaming video so you can start watching it immediately. Each video in this new collection will be released online over the next few months, available for free, of course, but if you don’t want to wait, you can watch all of them by streaming right now

And, remember, if you watch the videos on NutritionFacts.org or YouTube, you can access captions in several different languages. To find yours, click on the settings wheel in the lower-right of the video and then “Subtitles/CC.” Happy viewing!

If you are a $25+ monthly supporter and opted in to our donor rewards, you’re likely already an expert on these new topics by now, since you already received a complimentary link to the new download. If you’d like early access to new videos before they’re available to the public, please consider becoming a monthly supporter. Without your generosity, we wouldn’t be able to continue our work. Thank you!

 

Recipe: Roasted Kabocha with Kale-Cranberry Stuffing

Kabocha is a Japanese pumpkin, and this recipe makes a perfect, hearty meal. Rather than bread cubes, the stuffing for this dish is made with my Basic BROL, combined with onion, celery, kale, and cranberries. The recipe, originally published in The How Not to Diet Cookbook, can be found here. And see our Instagram for a video on how it’s made.

 

 

Key Takeaways: Sweet Potatoes

During the harsh Boston winters while I was in medical school, I would take two freshly microwaved sweet potatoes and pop them into my coat pockets to keep my hands warm. After they cooled down, I had healthy snacks on the go! They are one of my favorite vegetables, and I regularly eat them to check off the “other vegetables” boxes on my Daily Dozen checklist. For more information and my videos on this subject, visit the topic page.

 

New Plant-Based Nutrition Degree

I’m frequently asked, “How can I promote evidence-based nutrition professionally?” There’s a new way to get involved in our field! Loma Linda University has just launched a new Master of Science in Plant-Based Nutrition program. Check out the details here.

 

Volunteer Spotlight: Joan Davis

“During the last five years, I have moderated questions and responses from commenters on the videos and blogs Dr. Greger so brilliantly creates. As a nurse and former teacher, I appreciate the opportunity to provide responses that often involve some clarification, detective work, and sometimes even new discoveries. The chance to do this every week makes it especially rewarding to contribute to NF’s important, life-saving goals!

My favorite whole food, plant-based meal is a green salad loaded with beans and healthy carbs, and topped with seeds, nuts, and sprouts!”

 

 

Flash Sale Going on Now

Our extended Black Friday sale is live and will run through November 29! All merch on DrGreger.org is 20% off, including a couple of brand-new, limited-time items. Check it out.

 

 

 

 

Top Three Videos

The Dangerous Effects of Heavy Metal Music: How might we moderate the rare but very real risk of headbanging?

 

 

 

Medicinal Mushrooms for Cancer Survival: Did the five randomized controlled trials of reishi mushrooms in cancer patients show benefits in terms of tumor response rate, survival time, or quality of life?

 

 

Ochratoxin in Breakfast Cereals: One of the few food contaminants found at higher levels in those eating plant-based diets are mycotoxins, fungal toxins in moldy food ingredients, such as oats.

 

 

Live Q&As

Due to my writing schedule for my next book, How Not to Age, I will be taking a break from Q&As until April 2022. In the meantime, you can find links to past live Q&As here on NutritionFacts.org. And, remember, I have an audio podcast to keep you company, too. 

 

 

 

 

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

Does Cell Phone Radiation Affect Fertility?

Tue, 11/23/2021 - 07:00

What is the effect of cell phone radiation on sperm motility and DNA damage?

“Are men talking their reproductive health away?” There have been “unexplained declines in semen quality reported in several countries.” Might cell phones be playing a role? “Radio-frequency electromagnetic radiation (RF-EMR) from these devices could potentially affect sperm development and function.” The cell phone industry bristles at the “R word,” preferring the more innocuous-sounding “RF-EMFs” to radiation. It does have a point, though, about “radiation” being used by snake-oil hucksters of “radiation protection” gadgets. Radiation need not be atomic-bomb gamma rays. It can just be the warm glow of sunshine on your face, which is radiation, too. The question is: Does the specific type of radiation emitted by cell phones affect male fertility? I discuss this in my video Do Cell Phones Lower Sperm Counts?.

After the “World Health Organization (WHO) officially declared that cell phones…[could possibly] cause brain cancer,” many switched to hands-free devices, keeping their phones in their pants and using Bluetooth or other technology—away from the brain, but “close to the gonads.” Researchers put all the studies together, including nearly 1,500 semen samples, and found that “exposure to mobile phones was associated with reduced sperm motility…and viability,” though not necessarily sperm concentration.

How much was their swimming ability affected? Sperm motility appeared to be about 8 percent lower, but that alone may not actually translate into reduced fertility unless you’re starting out with a marginal sperm count. It might be better to avoid keeping an active cell phone near your crotch “in a trouser pocket for long periods of time,” especially if you’re a man who already has fertility problems. Cell phone exposure may just be one of a number of “modern day environmental exposures” that could add up. For example, Wi-Fi may be an issue. Researchers got semen samples from more than a thousand men, and “the total number of motile sperm…were decreased in a group who used a wireless internet compared with ones who used the wired internet.” 

These were all observational studies, though. Maybe men who use Wi-Fi just tend to smoke more, or maybe they ride more horses, and that’s the reason for the apparent link. You don’t know…until you put it to the test. Unfortunately, many of the studies were conducted on rats. While the microwaves emitted from a cell phone do not appear to affect rat testicles, it can be argued that you can’t necessarily extrapolate from these animal models, since, for example, their scrotums are “non pendulous,” meaning their testicles are more inside rather than swinging around outside their bodies. 

“Until proven otherwise, it is recommended that those with subfertility issues” may not want to keep their cell phones in their front pants pocket “in close proximity to the testicles. Even when not in use, mobile phones emit radiation periodically,” to keep pinging their location. Main exposure is during talk mode, however, when the device may still remain in the pocket, thanks to headsets or Bluetooth. What happens when you then have it in proximity to other common metal objects? I show a cross-section at crotch level at 3:02 in my video. You may have a metal zipper on your trousers and a key ring, along with your phone, in your pocket. “When all three objects were added, the SAR [the amount of radiation absorbed] in both the leg and in the testicles was generally increased and approximately doubled…” 

That’s only a problem if the radiation actually damages sperm, though. Can’t someone design a study where you simply wave a cell phone over some human sperm in a Petri dish to see if there’s an issue? Researchers did just that and, as you can see at 3:35 in my video, found significantly more DNA fragmentation in sperm exposed to cell phone radiation, starting within an hour of exposure. This is such a dramatic effect that they suggest women might not want to pocket their phones for a few days after trying to get pregnant, so as not to put the sperm at further risk. 

KEY TAKEAWAYS

  • Unexplained declines in semen quality have been reported in several countries, and radio-frequency electromagnetic radiation (RF-EMR) from cell phones may play a role.
  • After the World Health Organization (WHO) declared that cell phones may cause brain cancer, many switched to hands-free devices and began using Bluetooth or other technology while keeping their phones in their pants, away from the brain. Researchers found exposure to mobile phones to be associated with reduced sperm motility and viability, but not necessarily sperm concentration.
  • Wi-Fi use may also reduce the total number of motile sperm.
  • Research is on-going but, until proven otherwise, it has been recommended that men with subfertility issues may not want to keep their mobile phone in their front pants pocket near the testicles.
  • Main radiation exposure is during talk mode, but mobile phones still periodically emit radiation when not in use.
  • When a mobile phone and a common metal object, such as keys or a metal pants zipper, are in close proximity, the amount of radiation absorbed in the leg and in the testicles approximately doubled.
  • Researchers found significantly more DNA fragmentation in sperm exposed to cell phone radiation, starting within one hour of exposure. The effect is so dramatic that they suggest women might not want to put their mobile phones in their own pockets for a few days after trying to get pregnant, so as not to put the sperm at further risk.

What about laptops and WiFi? Should laptops not be in our laps after all? See Does Laptop Wi-Fi Lower Sperm Counts? and Flashback Friday: Do Cell Phones Lower Sperm Counts? & Does Laptop WiFi Lower Sperm Counts?

For more on brain issues, check out:

I cover male fertility in videos such as:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Fewer Than One in Ten Informed About Most Serious Downside of Mammograms

Thu, 11/18/2021 - 07:00

What do nine in ten women say they were never told about mammograms, even though they thought they had the right to know?

“Fueled by economic conflicts of interest”—with the multibillion-dollar mammogram industry—“and good intentions…many women [are] being given diagnoses of breast cancer that they did not need, producing unwarranted fear and psychological stress and exposing them to treatment that can only harm them.” Treatment they don’t need. As I discuss in my video Women Deserve to Know the Truth About Mammograms, this is the problem of overdiagnosis, “the detection of pseudo disease” or abnormalities picked up at mammogram screening that look like cancer under the microscope. So, you’re diagnosed with cancer and undergo treatment, but, all along, it was just pseudo disease that never would have actually progressed to cause symptoms. The “human costs” include mastectomies and even deaths. In fact, the chance of a woman benefiting from mammograms may be “ten times smaller than the risk that she may experience serious harm in terms of overdiagnosis.” 

“How many would elect to be screened [by mammogram] if they knew that for every one woman who is notionally saved by early detection, anywhere from 2 to 10 otherwise healthy women are being turned into breast cancer patients?” Well, first, are physicians even telling patients about the possibility of overdiagnosis? After all, “it is now recognized as the most serious downside” of mammogram screening. When hundreds of women were asked, fewer than one out of ten said they had been informed about it. And when they were told about the possibility of overdiagnosis, a little more than half said they wouldn’t agree to screening if it resulted in “more than 1 overtreated person per 1 life saved from death due to cancer.” “Wow. That implies that millions of Americans might not choose to be screened if they knew the whole story; however, most”—90 percent, in fact—“do not.” 

Most “women are aware about false-positives results and seem to view them as an acceptable consequence of screening mammography. In contrast, most women were unaware that screening can detect cancers that may never progress” and that what they don’t know could potentially even kill them. So, when considering the pros and cons of mammograms, it would be good to consider total mortality. Can the screening help you live longer on average? In fact, mammography “has not reduced total mortality, and it is therefore misleading to claim that ‘screening saves lives.’” 

Theoretically, routine mammograms should increase a nonsmoking 50-year-old woman’s “overall survival chance from 96.3% to 97.1% over 10 years.” However, “[t]hese statistics disregard deaths from overdiagnosis.” This includes deaths from the unnecessary “radiotherapy [radiation] and chemotherapy and thus increased mortality from heart disease and other malignancies [cancers] that may entirely outweigh the benefit in terms of reduced breast cancer mortality.” 

You can’t irradiate the breast without exposing the rest of your chest, including your heart and lungs, to radiation. This explains why breast cancer survivors can end up with “significant and marked impairment in cardiopulmonary [heart-lung] function over the entire continuum of disease.” “Radiation therapy as a treatment for breast cancer actually increases deaths from heart disease by more than 25% and from lung cancer by nearly 80%—a big risk for a woman who may not need to take it.” We might accept that risk if we were beating back a deadly cancer, but the “main effect of screening is to produce patients with breast cancer from among healthy women who would have remained free of breast disease for the rest of their lives had they not undergone screening.” That is, some women are being turned into cancer patients for whom treatment offers zero benefit. “Compelling data” suggest that “most overdiagnosed tumours would have regressed spontaneously without treatment.” 

“Still, individuals who have had a cancer detected and then removed are likely to feel that their life was saved,” but it’s perhaps ten times likelier that their lives were seriously harmed, not saved, and ten times likelier they were told they had a cancer that could kill them, but they really didn’t. Imagine being corralled into the operating room for surgery you didn’t need. Think about every doctor’s appointment and every sleepless night—all completely unnecessary—and yet you become mammograms’ greatest advocate, thinking screenings saved your life. That’s the crazy thing about mammograms and about PSA testing for prostate cancer, too. The people who are the most harmed are the ones who claim the greatest benefit.

“Overdiagnosis creates a powerful cycle…for more overdiagnosis because an ever increasing proportion of the population knows someone—a friend, a family member, an acquaintance, or a celebrity—who ‘owes their life’ to early cancer detection.” So, the worse the test is and the more overdiagnosis it causes, the more popular it becomes. Indeed, the “popularity paradox of screening” is that the more mammograms harm women, the better women seem to think they work, and the more breasts that are surgically removed completely unnecessarily, the more women swear by it.

Billions of dollars may be being wasted “for false-positive mammograms and breast cancer overdiagnosis” that could be spent on doing more for women’s health, but it’s the human costs that concern me, considering that the harms from breast cancer screening may outweigh the benefits when you include deaths caused by treatment. Based on some best- and worst-case scenario estimates, for every ten thousand women invited for ten years of mammogram screening, three to four breast cancer deaths may be avoided at the cost of around two to nine deaths from the long-term toxicity of unnecessary radiation treatments. Yet, only one in ten women undergoing mammography said they were ever told about overdiagnosis, even though nine out of ten thought they had the right to know.

Overdiagnosis is not easy to discuss. It’s a sensitive issue, but “just because communicating with patients will be difficult does not mean that we should not tackle this problem. Informed women deserve no less when deciding about breast cancer screening.” We have an ethical responsibility to let them know.

Women deserve to know the whole truth about mammograms so they can make up their own minds. I am not opposed to mammograms. I am opposed to the patronizing attitude that women should be pressured into getting them without being fully informed about the benefits and risks. Some women will still choose to get them, but others will not. It’s up to them to decide. 

KEY TAKEAWAYS

  • Overdiagnosis—the diagnosis and treatment of breast cancer that never would have even threatened the woman’s health—has resulted in many unnecessary surgeries, radiation regimens, and chemotherapy treatments, along with unwarranted fear and psychological stress.
  • The chance of a woman benefiting from mammograms may be “ten times smaller than the risk that she may experience serious harm in terms of overdiagnosis.”
  • How much do women know about the possibility of overdiagnosis? Fewer than one in ten said they had been informed about it, and more than half said that, had they known about the possibility of overdiagnosis, they wouldn’t agree to screening if it resulted in “more than 1 overtreated person per 1 life saved from death due to cancer.”
  • Although most are aware of false-positive results and accept them as a consequence of mammograms, most did not know that screening can detect cancers that may never progress at all.
  • Unnecessary radiation resulting from overdiagnosis exposes more than just the breast. The chest, including heart and lungs, are exposed, which is why breast cancer survivors may have significantly impaired cardiopulmonary function. Indeed, radiation therapy for breast cancer treatment increases deaths from heart disease by more than 25 percent and from lung cancer by nearly 80 percent.
  • With overdiagnosis, it is increasingly common to know someone who “owes their life” to early detection, so screening becomes even more popular.
  • The harms from breast cancer screening may outweigh any benefits. For every ten thousand women invited for ten years of mammogram screening, three to four breast cancer deaths may be avoided at the cost of around two to nine deaths from the long-term toxicity of unnecessary radiation treatments.
  • Only one in ten women undergoing mammography said they were ever informed about overdiagnosis, even though nine out of ten thought they had the right to know.

Check out the other videos in my 14-part series on mammograms:

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer and Flashback Friday: Can Flax Seeds Help Prevent Breast Cancer?

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?Is It Worth Getting Annual Health Check-Ups? and Is It Worth Getting an Annual Physical Exam?.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Overtreatment of Ductal Carcinoma In Situ

Tue, 11/16/2021 - 07:00

Nine out of ten women don’t realize that some breast cancers would never have caused any problems or even become known in one’s lifetime. This is an issue ductal carcinoma in situ has brought to the forefront.

The whole point of cancer screening is to “detect life-threatening disease at an earlier, more curable stage. Effective cancer-screening programs therefore both increase the incidence of cancer detected at an early stage and decrease the incidence of cancer presenting at a late stage.” Sounds reasonable because you’d find all those tiny cancers during screening that you would have missed before and be able to cut them out and pull them out of circulation. That’s not what appeared to happen with mammograms, though, as you can see at 0:30 in my video Overtreatment of Stage Zero Breast Cancer DCIS. As mammography ramped up in the 1980s, the diagnosis of early cancers did indeed shoot up. What we’d then like to see is a mirror image of this increase, with incidence of late-stage cancers dropping. If you caught the cancer early, it wouldn’t be around for late-stage cancer, right? Wrong. Late-stage cancer incidence didn’t seem to drop much at all.

Another way to look at this is by comparing mammogram rates around the country. The more mammograms you do, the more heavily screened the population is and the more early cancers you pick up. Great! And late, advanced disease should go down, too, right? Right, but it doesn’t. As you can see at 0:59 in my video, so many early cancers are being taken out of circulation with surgery, radiation, or other treatment, which should mean about the same number of late-stage cancers shouldn’t be found—that is, there should be an approximately equivalent drop in the number of late-stage cancers detected, but that didn’t happen. Mammograms catch a lot of small cancers, but with “no concomitant decline in the detection of larger cancers,” that would explain why the more mammograms you do, the more cancer you find, but death from breast cancer doesn’t seem to change much. Hold on. Tens of thousands of cancers are being cut out after screening. Why aren’t that many fewer women dying? “Together, these findings suggest widespread overdiagnosis,” meaning cancer picked up on mammograms that never would have progressed to the point of presenting during the woman’s lifetime and, so, wouldn’t have been noticed or caused any harm had it never been picked up at all.

So, going back to the graph I showed earlier, which you can see again at 2:00 in my video, if removing all those early-stage cancers didn’t lead to that many fewer late-stage cancers, that suggests that most would never have progressed during that time or may have even gone away on their own. That “could explain almost all the increase in incidence noted when mammography screening is done.” Indeed, “many invasive breast cancers detected by repeated mammography screening do not persist to be detected by screening at the end of 6 years, suggesting that the natural course of many of the screen-detected invasive breast cancers is to spontaneously regress,” that is, to spontaneously disappear.

We’ve known for more than a century that sometimes even serious metastatic breast cancer can just spontaneously go away. The problem is you can’t tell which is which, so if you find cancer, the natural inclination is to treat it. This can be especially tricky for ductal carcinoma in situ (DCIS), so-called stage zero breast cancer. Ductal means “in the breast ducts,” carcinoma means “cancer,” and in situ means “in place” or “in position,” not spreading outside of the duct. And, DCIS can create tiny calcifications that can be picked up on mammogram, as you can see at 3:07 in my video.

The whole point of mammograms was “to identify early invasive disease, so the large numbers of…DCIS diagnosed were unexpected and unwelcome.” “Prior to the advent of screening, ductal carcinoma in situ (DCIS) made up approximately 3% of breast cancers detected.” Now, DCIS accounts for a significant chunk. “The cells that make up DCIS look like invasive cancer…and therefore the presumption was made that these lesions were the precursors of cancer”—stage zero cancer—“and that early removal and treatment would reduce cancer incidence and mortality. However, long-term epidemiology [population] studies have demonstrated that the [surgical] removal of 50 000 to 60 000 DCIS lesions annually has not been accompanied by a reduction in the incidence of invasive breast cancers. This is in contrast to the experience with removal of colon polyps [with colonoscopy] and intraepithelial neoplasia lesions of the cervix [precancerous cervical lesions, thanks to pap smears], in which the removal of precursor lesions has led to a decrease in the incidence of colon and cervical cancer, respectively.” Those are cancer screening programs that work.

Radiologists argue that overdiagnosis isn’t so much the problem as is overtreatment. Certainly, it’s terrible to get a breast cancer diagnosis even though the cancer never would have hurt you, but you can’t know that at the time, so most women undergo aggressive surgical and radiation treatment. What happens when you compare the ten-year breast cancer survival rate for women with low-grade DCIS? Among those women who chose not to have surgery at all, 1.2 percent of them died of breast cancer within a decade. But, during that same ten years, of those women who did undergo surgery, having a lumpectomy or a full mastectomy, to cut out the cancer, 1.4 percent died from breast cancer. So, surgery appeared to make no difference.

Currently, randomized controlled trials are being conducted to put it to the test, but it is “incredibly difficult to convince a patient with a proven diagnosis of DCIS not to undergo the standard surgical therapy”—many just want to get it cut out. “The fear of cancer paralyzes patients…[who may] resort to drastic therapeutic measures that may not be necessary,” excessive measures like getting a double mastectomy. How can we prevent this? How about we change its name? “A U.S. National Cancer Institute working group has recommended dropping the term “carcinoma,” so maybe we should just call it an “indolent lesion of epithelial origin.” Let’s “use language that engenders less fear,” shall we? How bad can an “IDLE” tumor be?

Another option to avoid this dilemma? Just don’t get screened in the first place. Women aren’t typically told about any of this, though. Fewer than one in ten women were aware that mammograms carried any potential harms at all, and more than nine out of ten were unaware that some breast cancers never cause problems. Few had heard of DCIS, but when informed about it, most wished they had been told before they signed up for screening.

“Once a cancer is detected, it is currently not possible to distinguish life-threatening from indolent [potentially harmless] cases. Therefore, overdiagnosis can only be avoided by abstaining from breast screening” and skipping mammograms altogether.

That’s how researcher Alexandra Barratt explained her own decision to avoid screening: “I’m…worried by the possibility that I could be seriously harmed by the treatment of a cancer that would never have affected my health.” Given that the only way to avoid opening that “Pandora’s box” was by not getting mammograms, she decided to try to improve her diet and lifestyle to prevent getting breast cancer in the first place.

KEY TAKEAWAYS

  • The purpose of cancer screening is the early detection of life-threatening disease when it is at a more easily curable stage. As mammography screening ramped up in the 1980s, however, the diagnosis of early cancers increased while late-stage cancer incidence did not experience much of a decline.
  • Mammograms pick up many early cancers, which may then be eliminated by surgery, radiation, or chemotherapy, the reason there isn’t a decline in about the same number of late-stage cancers being found may be widespread overdiagnosis—the diagnosis and treatment of breast cancer that never would have even threatened the woman’s health.
  • Many invasive breast cancers identified during mammography screening may spontaneously disappear. Even serious metastatic breast cancer may spontaneously regress, something we’ve known for more than a century.
  • The natural inclination to finding cancer is to treat it, which is particularly challenging for ductal carcinoma in situ (DCIS), so-called stage zero breast cancer. DCIS can create tiny calcifications that can be picked up on mammogram, and its cells look like invasive cancer. However, surgical removal of DCIS lesions hasn’t been accompanied by a reduction in the incidence of invasive breast cancers.
  • In comparing the ten-year breast cancer survival rate for women with low-grade DCIS, among those who chose not to have surgery, 1.2 percent died of breast cancer within a decade. During that same period, 1.4 percent of those who had a lumpectomy or full mastectomy died from breast cancer. So, surgery didn’t seem to make any difference.
  • To help reduce the fear of cancer that can paralyze patients, a U.S. National Cancer Institute working group has recommending dropping the word “carcinoma” in DCIS and changing it to “indolent lesion of epithelial origin,” IDLE.
  • Avoiding screening is another option to avoiding overdiagnosis, but fewer than one in ten women are aware that mammograms carry any potential harms at all and more than nine in ten are unaware that some breast cancers never cause problems.

How might someone improve their diet and lifestyle to lower breast cancer risk? See, for example:

This is the ninth in a 14-part series on mammograms, which includes: 

For more on breast cancer, see my videos Oxidized Cholesterol 27HC May Explain Three Breast Cancer MysteriesEggs and Breast Cancer, and Flashback Friday: Can Flaxseeds Help Prevent Breast Cancer?.

I was able to cover colon cancer screening in just one video. If you missed it, see Should We All Get Colonoscopies Starting at Age 50?.

Also on the topic of medical screenings, check out Flashback Friday: Worth Getting an Annual Health Check-Up and Physical Exam?, Is It Worth Getting Annual Health Check-Ups?, and Is It Worth Getting an Annual Physical Exam?.

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Millions of Years of Healthy Life Lost Due to Cannabis

Thu, 11/11/2021 - 07:00

Every year, cannabis is estimated to result in two million years of healthy life lost due to disability. How much is that compared with alcohol and tobacco?

“The popular notion seems to be that marijuana is a harmless pleasure,” but what are the potential adverse effects of marijuana use? That’s not an easy question to answer, as I discuss in my video Does Marijuana Cause Health Problems?.

Most studies to date have been “cross-sectional or rely on self-reported health.” Cross-sectional studies are snapshots in time, so you don’t know which came first: Are people sick because they’re smoking marijuana, or are they smoking marijuana because they’re sick? If you ask people how they are feeling, pot smokers may say, “I feel great!” even if they are actually suffering from a health problem. There have been few longitudinal studies—those conducted over a period of time—using objective measures of health…until now.

More than a thousand individuals were followed from birth to age 38. Researchers tested associations between cannabis use over decades and “multiple domains of physical health,” and looked at 12 health outcomes. Tobacco use was associated with worse health for 8 of the 12 health outcomes, from impaired lung function to systemic inflammation and metabolic derangements. Cannabis use, on the other hand, was associated with…gum disease. That’s it? Indeed, “cannabis use was unrelated to other physical health problems.” 

Periodontal disease can lead to tooth loss and there may be other dental health problems associated with smoking marijuana, but when cannabis is described as “nefarious,” the first thing to come to mind is probably not gingivitis.

Is it possible that cannabis users are living healthier-than-average lifestyles to counteract the effects of the drug? Are they eating more fruits and vegetables, for example, or maybe drinking less alcohol? No, and neither are pot smokers exercising more. So, the “absence of associations between cannabis use and poor physical midlife health could not be attributed to better initial health, more physical activity, better diet, or less alcohol abuse.” Maybe marijuana just isn’t that bad. 

Heroin use and cocaine use may increase your risk of dying, but no association was found between mortality and marijuana. However, the researchers only followed the subjects until age 38. To find out what happens after that, we have to turn to Sweden, where they recently published the longest study ever on cannabis and mortality. Fifty thousand men were followed “up to around age 60.” About 30 years ago, when they first reported on this cohort, no significant excess mortality was found among cannabis users, or “abusers,” as they called them. But, back then, the men were in their thirties, as in the other study. What happens when you follow them past middle age, “when the health-related detrimental effects” might begin to emerge? Those with a history of heavy cannabis use did end up having “a significantly higher risk of death,” a 40 percent higher risk of dying prematurely. 

But, I thought cannabis didn’t kill. As you can see at 3:20 in my video, cocaine kills thousands of Americans every year, alcohol kills tens of thousands, and tobacco breaks the graph, killing hundreds of thousands of people in the United States every year—but marijuana doesn’t even make it onto the graph.

What they were referring to, though, is that “no deaths have been directly attributed to the acute physical toxicity of cannabis.” When a 19 year old eats a cannabis cookie and then jumps off a fourth-floor balcony, the direct cause of death—trauma—is attributed to the fall, but that doesn’t mean cannabis didn’t contribute.

It’s true that people don’t directly overdose on cannabis as you can with opiates, which can shut down your breathing. Unlike many pharmaceuticals, for which a harmful dose may be just a few times larger than a prescribed dose, the therapeutic index for cannabis is 40,000 to 1. Does that mean you could smoke 40,000 joints without overdosing? No. In fact, you may be able to smoke two million joints before a lethal overdose. Cannabis use contributes more to disease than death, in part because people aren’t injecting it, but the health-related harms of cannabis weren’t quantified on a global scale until 2013.

As you can see at 4:47 in my video, cannabis is estimated to result in two million years of healthy life lost due to disability every year. Now, that is tiny compared with the hundred million years or so attributed to alcohol or tobacco use, but it still results in a lot of pain and suffering. But what about the gum disease study I discussed earlier? I thought the only physical health problems associated with cannabis use were dental in nature. In that study, the researchers were looking at a specific set of health concerns and emphasized that the periodontal problems were in addition to all the other potential issues, such as increased risk of accidents and injuries, bronchitis, heart attacks and strokes, possible infectious diseases, and cancer, as well as mental health concerns. As a more direct cause of death, though, marijuana may be suspected in only hundreds of deaths over an eight-year period, whereas a single pharmaceutical drug—Viagra—was involved in thousands.

KEY TAKEAWAYS

  • A longitudinal study conducted over a period of time and using objective health measures followed more than a thousand individuals from birth to age 38. Researchers found that tobacco use was linked with worse health for 8 of the 12 health outcomes assessed, such as impaired lung function and systemic inflammation, whereas cannabis use was associated only with gum disease and was determined to be unrelated to other physical health problems.
  • Cannabis users were not found to be living healthier-than-average lifestyles, so this absence of a link between marijuana use and poor physical midlife health couldn’t be attributed to better initial health, more exercise, a healthier diet, or less alcohol consumption.
  • The longest study ever on cannabis and mortality came out of Sweden, where researchers followed 50,000 men up to around age 60. They first reported on the subjects when they were around 30 years old and found no significant excess mortality among cannabis users. Around age 60, however, those with a history of heavy marijuana use had a 40 percent higher risk of dying prematurely.
  • Why, then, does marijuana have the reputation of not being a killer? Cocaine, alcohol, and tobacco have all been directly linked to deaths, but not marijuana. That is because deaths have not been directly attributed to “the acute physical toxicity of cannabis”—but that doesn’t mean marijuana didn’t contribute to an accident occurring after cannabis use, for example.
  • Users don’t overdose on cannabis as they can with opiates, for instance, but marijuana use does contribute to disease. It’s been estimated that cannabis use results in two million years of healthy life lost due to disability every year.

If you want to take a deep dive into the cannabis research, I made a whole DVD you may be interested in. See Cannabis: What Does the Science Say.

My other videos on cannabis include:

The cannabis issue reminds me of a similar clash of politics and commercial interests in the cell phone debate. If you’re interested, check out my videos Does Cell Phone Radiation Cause Cancer? and Cell Phone Brain Tumor Risk?.

You might also want to check out some of my videos on smoking:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

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