The Natural Human Diet

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Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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:

Image Credit: Nathan Rupert / Flickr

Original Link

The Natural Human Diet

NF-Nov15 The Problem with the Paleo Diet Argument copy.jpg

Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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:

Image Credit: Nathan Rupert / Flickr

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Paleo Diet May Undermine Benefit of CrossFit Exercise

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Much of the low-carb and paleo reasoning revolves around insulin. To quote a paleo blogger, "carbohydrates increase insulin, the root of all evil when it comes to dieting and health." So the logic follows that because carbs increase insulin, we should stick mostly to meat, which is fat and protein with no carbs, so no increase in insulin, right?

Wrong.

We've known for half a century that if you give someone just a steak: no carbs, no sugar, no starch; their insulin goes up. Carbs make our insulin go up, but so does protein.

In 1997 an insulin index of foods was published, ranking 38 foods to determine which stimulates higher insulin levels. Researchers compared a large apple and all its sugar, a cup of oatmeal packed with carbs, a cup and a half of white flour pasta, a big bun-less burger with no carbs at all, to half of a salmon fillet. As you can see in the graph in my video Paleo Diets May Negate Benefits of Exercise, the meat produced the highest insulin levels.

Researchers only looked at beef and fish, but subsequent data showed that that there's no significant difference between the insulin spike from beef, chicken, or pork--they're all just as high. Thus, protein and fat rich foods may induce substantial insulin secretion. In fact, meat protein causes as much insulin release as pure sugar.

So, based on the insulin logic, if low-carbers and paleo folks really believed insulin to be the root of all evil, then they would be eating big bowls of spaghetti day in and day out before they would ever consume meat.

They are correct in believing that having hyperinsulinemia, high levels of insulin in the blood like type 2 diabetics have, is not a good thing, and may increase cancer risk. But if low-carb and paleo dieters stuck to their own insulin theory, then they would be out telling everyone to start eating plant-based. Vegetarians have significantly lower insulin levels even at the same weight as omnivores. This is true for ovo-lacto-vegetarians, lacto-vegetarians, and vegans. Meat-eaters have up to 50% higher insulin levels.

Researchers from the University of Memphis put a variety of people on a vegan diet (men, women, younger folks, older folks, skinny and fat) and their insulin levels dropped significantly within just three weeks. And then, just by adding egg whites back to their diet, their insulin production rose 60% within four days.

In a study out of MIT, researchers doubled participants' carbohydrate intake, and their insulin levels went down. Why? Because the researchers weren't feeding people jellybeans and sugar cookies, they were feeding people whole, plant foods, lots of whole grains, beans, fruits, and vegetables.

What if we put someone on a very-low carb diet, like an Atkins diet? Low carb advocates such as Dr. Westman assumed that it would lower insulin levels. Dr. Westman is the author of the new Atkins books, after Dr. Atkins died obese with, according to the medical examiner, a history of heart attack, congestive heart failure, and hypertension. But, Dr. Westman was wrong in his assumption. There are no significant drop in insulin levels on very low-carb diets. Instead, there is a significant rise in LDL cholesterol levels, the number one risk factor for our number one killer, heart disease.

Atkins is an easy target though. No matter how many "new" Atkins diets that come out, it's still old news. What about the paleo diet? The paleo movement gets a lot of things right. They tell people to ditch dairy and doughnuts, eat lots of fruits, nuts, and vegetables, and cut out a lot of processed junk food. But a new study published in the International Journal of Exercise Science is pretty concerning. Researchers took young healthy people, put them on a Paleolithic diet along with a CrossFit-based, high-intensity circuit training exercise program.

If you lose enough weight exercising, you can temporarily drop our cholesterol levels no matter what you eat. You can see that with stomach stapling surgery, tuberculosis, chemotherapy, a cocaine habit, etc. Just losing weight by any means can lower cholesterol, which makes the results of the Paleo/Crossfit study all the more troubling. After ten weeks of hardcore workouts and weight loss, the participants' LDL cholesterol still went up. And it was even worse for those who started out the healthiest. Those starting out with excellent LDL's (under 70), had a 20% elevation in LDL cholesterol, and their HDL dropped. Exercise is supposed to boost our good cholesterol, not lower it.

The paleo diet's deleterious impact on blood fats was not only significant, but substantial enough to counteract the improvements commonly seen with improved fitness and body composition. Exercise is supposed to make things better.

On the other hand, if we put people instead on a plant-based diet and a modest exercise program, mostly just walking-based; within three weeks their bad cholesterol can drop 20% and their insulin levels 30%, despite a 75-80% carbohydrate diet, whereas the paleo diets appeared to "negate the positive effects of exercise."

I touched on paleo diets before in Paleolithic Lessons, and I featured a guest blog on the subject: Will The Real Paleo Diet Please Stand Up?

but my favorite paleo videos are probably The Problem With the Paleo Diet Argument and Lose Two Pounds in One Sitting: Taking the Mioscenic Route.

I wrote a book on low carb diets in general (now available free full-text online) and touched on it in Atkins Diet: Trouble Keeping It Up and Low Carb Diets and Coronary Blood Flow.

And if you're thinking, but what about the size of the cholesterol, small and dense versus large and fluffy? Please see my video Does Cholesterol Size Matter?

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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Vincent Lit / Flickr

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How to Eliminate 90 Percent of Heart Disease Risk

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Medical myths and dogmas die hard. Researchers creating a new body of knowledge for prevention and control of heart disease had to disprove a bunch of doozies. For example, we used to think that heart disease, high cholesterol and high blood pressure were just inevitable consequences of aging. All these are now bygone notions, refuted by massive data. Other long-standing myths and dogmas about our number one killer epidemic persist, however. For example, many still think that major risk factors like cholesterol account for a minority of risk, and that many people have heart attacks with no risk factors at all.

There are rare genetic conditions that give people high cholesterol no matter what they eat, but such genetic defects occur in no more than 1 in 200 people. As you can see in my video, Eliminating 90% of Heart Disease Risk, this means that most people with atherosclerosis acquire it by what they put in their mouth.

One study showed that for men and women, old and young, and in all areas of the world, nine potentially modifiable factors like diet, exercise, and smoking, accounted for over 90 percent of the proportion of the risk of having a heart attack. This has also been confirmed in prospective studies such as the Harvard Health Professional's Follow-up, which showed that making healthy lifestyle choices are associated with a 90 percent drop in risk in men followed over time. This is true for women as well, who had a 92 percent drop in risk.

The same goes for diabetes--91 percent of cases could be attributed to bad habits and behaviors. And the same healthy lifestyle, which includes not smoking, eating a healthy diet, exercising and maintaining an optimal body weight, may reduce the risk of multiple chronic diseases such as stroke. Up to 80 percent of strokes are avoidable with simple lifestyle changes.

How does this all compare to drugs? Why change our diet, lose weight and start exercising if we can just pop some pills? Pharmacological therapies, including cholesterol lowering statin drugs and blood pressure pills, typically only reduce cardiovascular disease risk by 20 percent to 30 percent, not 90 percent like lifestyle changes. So even on drugs, 70 to 80 percent of heart attacks still occur.

One of the great things about the Harvard Health Professional's Follow-up is that they also looked at the effect of lifestyle changes on people already on medications. Even those on cholesterol and blood pressure lowering drugs may be able to get a further 78 percent drop in risk by eating and living healthfully. So the choice isn't diet or drugs. Cardiovascular medications "should be used as an adjunct to, not just a replacement for, healthy lifestyle practices."

It takes time for new science to trickle down into mainstream medical practice. The practice of cardiology and medicine in general may correspond, on average, to what was being published 10 or 20 years before. So it's important to know if your doctor is still stuck practicing 20th century medicine.

Chronic disease, then--the leading cause of death and disability--may be a choice. See for example, Cavities and Coronaries: Our Choice. What do you choose?

Why reduce a preventable disease just 90%? How about 99.9%? See One in a Thousand: Ending the Heart Disease Epidemic

More from the field of lifestyle medicine:

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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

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Dietary Cholesterol Affects Blood Cholesterol Levels

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In my video, Eggs vs. Cigarettes in Atherosclerosis, I profiled a study showing that both smoking and eating eggs can harm our arteries. But even egg yolks alone were associated with artery-clogging plaque buildup nearly two thirds as bad as smoking.

This certainly ruffled some feathers.

Yes, eggs are by far the number one source of cholesterol in the American diet, but some letters to the editor protested that dietary cholesterol may have very little impact on blood cholesterol levels, citing a study published in 1971 performed on eight people. But if one looks at dozens of studies together, covering hundreds of study subjects, we find that blood cholesterol concentration is "clearly increased by added dietary cholesterol." In my video, Debunking Egg Industry Myths, there is an extreme example just to illustrate: a year in the life of a study subject taken on and off eggs. First, the researchers take him off eggs, putting him on a cholesterol-free diet, and his blood cholesterol plummets within just three weeks. Then they give him lots of eggs, and his cholesterol shoots back up, stays high until they take the eggs away and put him back on the cholesterol free diet, and so on and so forth. The researchers were essentially turning his high blood cholesterol on and off like a light switch (made out of eggs).

Of course the only reason we care our about our cholesterol levels or how much plaque is building up inside our arteries is because we want to avoid the consequences, like a heart attack. So do eggs increase our risk of cardiovascular disease? The latest meta-analysis, the latest compilation of all the best studies on egg consumption and risk of heart disease going back to 1930, found that, overall, those who ate the most eggs had a 19% increased risk of cardiovascular disease, a 68% increased risk of diabetes, and, once you have diabetes, an even greater 85% increased risk of heart disease. It didn't take much; less than a single egg a day was associated with a significantly increased risk of heart disease. Just over half an egg a day may increase heart disease risk 6% (40% in separated diabetes patients), and the risk of diabetes by 29%. The researchers conclude that their findings support the American Heart Association dietary guidelines, which advise restricted egg consumption in adults for preventing cardiometabolic disease, like diabetes, our seventh leading cause of death, and heart disease, our number one killer.

More on the diabetes connection in Eggs and Diabetes and Bacon, Eggs, and Gestational Diabetes During Pregnancy.

More on eggs and the egg industry in general:

There's more to heart disease than just cholesterol buildup. In my video, Eggs and Arterial Function, I explore what effect egg consumption has on endothelial function, the ability of our arteries to relax normally.

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my videos for free by clicking here and watch my full 2012 - 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Rebecca Siegel / Flickr

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Blood Type Diet Perceived as "Crass Fraud"

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It was Adolf Hitler who coined a propaganda technique he called, "The Big Lie," arguing that people may be more likely to believe colossal untruths, because they would not believe that others could have the impudence to distort the truth so infamously, so in the big lie there is always a certain force of credibility.

Dr. Peter D'Adamo's book Eat Right for Your Type makes the astounding claim that people with different blood types should eat different foods. Type O's, for example, are supposed to be like the hunter and eat a lot of meat, whereas type A's are supposed to eat less. A 2013 systematic review of the evidence supporting blood type diets was published in one of the world's most prestigious nutrition journals. The researchers didn't find any.

The researchers sifted through over a thousand papers that might shed some light on the issue, and none of the studies showed an association between blood type diets and health-related outcomes. They conclude that "there is currently no evidence that an adherence to blood type diets will provide health benefits, despite the substantial presence and perseverance of blood type diets within the health industry."

Ten years earlier, the Journal of the Norwegian Medical Association released a number of papers that came out of a day-long scientific seminar held by the Norwegian Society for Nutrition. 40,000 copies of the Eat Right for Your Type had been sold in Norway, and so the researchers sought to determine whether blood type diets were visionary science or nonsense. They also concluded that they are nonsense.

The author of the blood type diet book responded to the review on his website, saying that "there is good science behind the blood type diet, just like there was good science behind Einstein's mathematical calculations." He says that if blood type diets were just tested in the right way, like Einstein's E=MC2, he would be vindicated. The reason we don't see any studies on blood types and nutrition, he complains, is "because of little interest and available money." But he's sold more than seven million books. Why doesn't he fund his own studies? That's what the Atkins Corporation did.

In fact, he has! In 1996, he wrote, "I am beginning the eighth year of a ten year trial on reproductive cancers, using the Blood Type Diets ... By the time I release the results in another 2 years, I expect to make it scientifically demonstrable that the Blood Type Diet plays a role in cancer remission." OK, so that would be 1998. The results? Still not released, sixteen years later.

Good tactic, though, saying you're just about to publish a study and banking that nobody would actually follow up. So in his sequel, he said he was currently conducting a "twelve-week randomized, double-blind, controlled trial implementing the Blood Type Diet, to determine its effects on the outcomes of patients with rheumatoid arthritis." (See my video Blood Type Diet Debunked). That was ten years ago.

As my Norwegian colleague bemoaned, "it is difficult not to perceive the whole thing as a crass fraud."

So rarely are popular press diet books afforded such fact-checking. Kudos to these researchers. If only we had this 13 years ago when the book was on the bestseller list!

I have a few videos on popular diets, such as:

I also wrote a book about low-carb diets, which is now available free online full-text at AtkinsFacts.org.

Unfortunately, nutrition illiteracy is not just a problem among the public, but among the medical profession:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Zappy's Technology Solution / Flickr

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Peeks Behind the Egg Industry Curtain

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The American Egg Board is a promotional marketing board appointed by the U.S. government whose mission is to "increase demand for egg and egg products on behalf of U.S. egg producers." If an individual egg company wants to run an ad campaign, they can say pretty much whatever they want. But if an egg corporation wants to dip into the 10 million dollars the American Egg Board sets aside for advertising every year, because the board is overseen by the federal government, corporations are not allowed to lie with those funds. This leads to quite revealing exchanges between egg corporations that want to use that money and the USDA on what egg companies can and cannot say about eggs.

Thanks to the Freedom of Information Act I was able to get my hands on some of those emails. Of course a lot of what I got were pages with nearly all of the text blacked out (you can see these in my video, Who Says Eggs Aren't Healthy or Safe?). But I did find some illuminating correspondence. For example, one email shows an egg company trying to put out a brochure on healthy snacking for kids. But because of existing laws against false and misleading advertising, the head of the USDA's poultry research and promotion programs reminds the company that eggs or egg products cannot be couched as being healthy or nutritious. "The words nutritious and healthy carry certain connotations, and because eggs have the amount of cholesterol they do, plus the fact that they're not low in fat, [the words healthy and nutritious] are problematic." This is the United States Department of Agriculture saying this!

However, the USDA official helpfully suggests, "I believe you can say something that's just as strong if not stronger, that is 'naturally nutrient-dense.'" Why can we say eggs are nutrient-dense but not nutritious? Because there's no legal definition of nutrient-dense. We can say Twinkies and Coca Cola are nutrient dense, but legally, we can't say something is nutritious unless it's actually... nutritious.

For example, the egg industry wanted to run an ad calling eggs a nutritional powerhouse that aids in weight loss. The USDA had to remind the industry that they can't portray eggs as a diet food because of the fat and cholesterol content. In fact, eggs have nearly twice the calories of anything that can be called "low-calorie."

"Nutritional powerhouse" can't be used either. Fine, the industry said, they'll move to plan B, and headline the ad "Egg-ceptional Nutrition." They couldn't say that either because, again, given the saturated fat and cholesterol you can't legally call eggs nutritious. So the headline ended up as, "Find true satisfaction," and instead of weight loss they had to go with "can reduce hunger." The USDA congratulated them on their cleverness. Yes, a food that when eaten can reduce hunger--what a concept!

They can't even say eggs are "relatively" low in calories. Can't say eggs are low in saturated fat--they're not. Can't say they're relatively low in fat, they're not. Can't even call them a rich source of protein, because, according to the USDA, they're not.

It's illegal to advertise that eggs pack a nutritional wallop, or that they have a high nutritional content. Eggs have so much cholesterol, we can't even say they "contribute nutritionally." Can't say eggs are "healthful," certainly can't say they're "healthy." Can't even say eggs contribute "healthful components."

Since we can't say eggs are a healthy start to the day, the USDA suggests a "satisfying start." Egg corporations can't call eggs a healthy ingredient, but they can call eggs a "recognizable" ingredient. Can't truthfully say eggs are good for us, either. By law, according to the USDA, the egg industry "needs to steer clear of words like 'healthy' or 'nutritious.'"

For a food to be labeled "healthy" under FDA rules, it has to be low in saturated fat (eggs fail that criteria) and have less than 90mg of cholesterol per serving (even half an egg fails that test). For the same reason we can't tout ice cream for strong bones, we can't say eggs are healthy because they exceed the threshold for cholesterol.

Egg corporations aren't even allowed to say things like "Eggs are an important part of a well balanced, healthy diet" on an egg carton because it would be considered misleading according to the USDA's National Egg Supervisor, since eggs contain significant amounts of fat and cholesterol and therefore can contribute to the leading killer in the United States, heart disease.

The industry can't afford to tell the truth about the eggs, or even the hens that lay them. The industry crams five to ten birds in cages the size of a file cabinet their whole lives, but when providing footage to the media, the American Egg Board instructs, "do not show multiple birds in cages--they look too crowded and open us up to activist criticism."

Not only is the industry barred from saying eggs are healthy, they can't even refer to eggs as safe because more than a hundred thousand Americans are food poisoned by Salmonella from eggs every year.

The egg board's response to this egg-borne epidemic is that Salmonella is a naturally occurring bacterium. An internal egg industry memo didn't think that should necessarily be the key message, fearing that "it may be counterproductive by implying there is no avoiding Salmonella in eggs aside from avoiding eggs altogether."

The food poisoning risk is why the American Egg Board can't even mention anything but eggs cooked hard and dry. No soft-boiled, no over-easy, no sunny-side up--because of the Salmonella risk. The American Egg Board's own research showed that the sunny-side up cooking method should be considered "unsafe."

In light of bird flu viruses, both the white and yolk must be cooked firm. The VP of marketing for the Egg Board complained to the USDA saying they'd "really like to not have to dictate that the yolks are firm," and cites a Washington Post article saying runny yolks may be safe for everyone except pregnant women, infants, elderly, or those with chronic disease. It turns out it was a misquote--eggs can't be considered safe for anyone.

Instead of safe, they can call eggs "fresh," the USDA marketing service helpfully suggests. But they can't call eggs safe, and they can't say eggs are "safe to eat." They can't even mention safety at all.

Wait a second, not only can eggs not be called healthy they can't even be called safe? Says who? Says the United States Department of Agriculture.

For more peeks behind the egg industry curtain see:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: U.S. Department of Agriculture / Flickr

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What’s Driving America’s Obesity Problem?

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Currently, nearly two-thirds of Americans are overweight. By 2030 it is estimated more than half our population may be clinically obese. Childhood obesity has tripled, and most children will grow up to be overweight as well. The United States may be in the midst of raising the first generation since our nation's founding that will have a shorter predicted life span than that of the previous generation.

The food industry blames inactivity. We just need to move more, they say. But what is the role of exercise in the treatment of obesity?

"There is considerable debate in the medical literature today about whether physical activity has any role whatsoever in the epidemic of obesity that has swept the globe since the 1980s." The increase in calories per person is more than sufficient to explain the U.S. epidemic of obesity. In fact, if anything, the level of physical activity over the last few decades has actually gone up in both Europe and North America.

This has important policy implications. We still need to exercise more, but the priorities for reversing the obesity epidemic should focus on the overconsumption of calories (See How Much Exercise to Sustain Weight Loss?). American children are currently eating about an extra 350 calories (equal to about a can of soda and small fries), and adults are eating about an extra 500 calories (equal to about a Big Mac). We'd have to walk two hours a day, seven days a week to burn off those calories. So exercise can prevent weight gain, but the amount required to prevent weight gain may be closer to twice the current recommendations. It's more effective to stick to foods rich in nutrients but poor in calories: see my video Calculate Your Healthy Eating Score. It's cheaper too, see Best Nutrition Bang For Your Buck.

Public health advocates have been experimenting with including this kind of information. One study found that fast food menus labeled with calories and the number of miles to walk to burn those calories appeared the most effective in influencing the selection of lower calorie meals.

Exercise alone may have a small effect, and that small effect can make a big difference on a population scale. A 1% decrease in BMI nationwide might prevent millions of cases of diabetes and heart disease and thousands of cases of cancer. But why don't we lose more weight from exercise? It may be because we're just not doing it enough. "The small magnitude of weight loss observed from the majority of exercise interventions may be primarily due to low doses of prescribed exercise."

People tend to overestimate how many calories are burned by physical activity. For example, there's this myth that a bout of sexual activity burns a few hundred calories. So may think, "Hey, I could get a side of fries with that." But if we actually hook people up and measure energy expenditure during the act (and the study subjects don't get too tangled up with all the wires and hoses) it may be only close to the metabolic equivalent of calisthenics. Given that the average bout of sexual activity only lasts about six minutes, a young man might expend approximately 21 calories during sexual intercourse. Due to baseline metabolic needs, he would have spent roughly one third of that just lying around watching TV, so the incremental benefit is plausibly on the order of 14 calories. So maybe he could have one fry with that.

I previously touched on this in my video Diet or Exercise, What's More Important For Weight Loss?

Don't get me wrong--exercise is wonderful! Check out, for example:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Glamhag / Flickr

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The Reversal on Fish Oil

NF-Feb26 Is Fish Oil Just Snake Oil?.jpg

Are the purported benefits of fish oil supplementation for the prevention and treatment of heart disease just a "fish tale"? Thanks to recommendations from organizations such as the American Heart Association that individuals at high risk for heart disease ask their physicians about fish oil supplementation, fish oil has grown into a multibillion dollar industry. We now consume over 100,000 tons of fish oil every year.

But what does the science say? A systematic review and meta-analysis published in the Journal of the American Medical Association, highlighted in my video Is Fish Oil Just Snake Oil? looked at all the best "randomized clinical trials evaluating the effects of omega-3's on lifespan, cardiac death, sudden death, heart attack, and stroke." The studies told the subjects to either eat more oily fish or to take fish oil capsules. What did the study find? Overall, the researchers found no protective benefit for all-cause mortality, heart disease mortality, sudden cardiac death, heart attack, or stroke.

What about for those who already had a heart attack and are trying to prevent another? Still no benefit. Where did we even get this idea that omega 3's were good for the heart? If we look at some of the older studies, the results seemed promising. For example, there was the famous DART trial back in the 80s involving 2,000 men. Those advised to eat fatty fish had a 29% reduction in mortality. Pretty impressive--no wonder it got a lot of attention. But people seemed to have forgotten the sequel, the DART-2 trial. The same group of researchers, and an even bigger study (3,000 men). In DART-2 "those advised to eat oily fish and particularly those supplied with fish oil capsules had a higher risk of cardiac death."

Put all the studies together, and there's no justification for the use of omega 3s as a structured intervention in everyday clinical practice or for guidelines supporting more dietary omega-3's. So what should doctors say when their patients follow the American Heart Association advice to ask them about fish oil supplements? Given this and other negative meta-analyses, "our job as doctors should be to stop highly marketed fish oil supplementation in all of our patients."

I've previously discussed fish oil supplements in the context of risks versus purported cardiovascular benefits:

But if the benefits aren't there, then all one is left with are concerns over the industrial pollutants that concentrate in the fish fat (even in distilled fish oil, see Is Distilled Fish Oil Toxin-Free?).

These same contaminants are found in the fish themselves. This raises concern for adults (Fish Fog), children (Nerves of Mercury), and pregnant moms:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day ,and From Table to Able.

Image Credit: Jo Christian Oterhals / Flickr

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My Three Most Surprising Blogs of 2014

These Eye-Opening Articles Demolish Dangerous Nutrition Myths

When I began researching meatless eating in 1995, I thought I was knowledgeable about nutrition. After all, everything I had been told from middle school on, whether from teachers, doctors, or the media, agreed that animal foods were necessary for good health. Meat was the center of my lunches and dinners.

My two daughters, then ages 11 and 13, had just declared they would not eat meat. Fooled by constant bombardment girl surprised and dismayed smaller.jpgwith food myths, I began to frantically study how to keep the kids alive and healthy until they began to eat meat again.

As I dug into facts in medical journal articles, books by plant-based dietitians and doctors, and conferences with national experts, I was stunned. Astonished. Dismayed. Because what I was finding was that everything I'd learned about nutrition was wrong. The truth directly contradicted my lifetime of accepting routine "information" on healthy eating. At first I was resistant to new ideas - who wouldn't be?

But as my perception began to shift, I got hooked on nutrition research, and my pursuit of facts continues to this day. I authored The Perfect Formula Diet to let others know what I was discovering, and continue to share developing thinking and science with everyone I can with my ongoing blogs.

Science in 2014 did not disappoint, continuing to support whole foods, plant-based diets as the most important element in achieving glowing health, abundant energy, and vigorous longevity. So I continue to author articles to bust the animal-food myths that are destroying the health of unsuspecting people, not to mention the life-support systems of our planet.

Here are the three of my 2014 posts that should prove most surprising to anyone who has not yet questioned obsolete nutrition myths.

Click here for the three most surprising blogs of 2014

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