Four Ways to Improve on the Mediterranean Diet

Improving on the Mediterranean Diet.jpg

The traditional Mediterranean diet can be considered mainly, but not exclusively, as a plant-based diet, and certainly not a whole foods, plant-based diet. Olive oil and wine can be considered essentially fruit juices. Even if one is eating a "vegiterranean diet," an entirely plant-based version, there are a number of problematic nutritional aspects that are rarely talked about. For example, the Mediterranean diet includes lots of white bread, white pasta and not a lot of whole grains.

In an anatomy of the health effects of the Mediterranean diet, the single most important component was the high consumption of plant foods. In contrast, high cereal consumption, meaning high grain consumption, did not appear to help. This may be because most grains that modern Mediterranean dieters eat are refined, like white bread, whereas the traditional Mediterranean diet was characterized by unprocessed cereals--in other words, whole grains. And while whole grains have been associated with lower risk of diabetes, heart disease and cancer, refined grain may increase the risk of diabetes, obesity, heart disease and other chronic diseases. In the PREDIMED study, those who ate the most white bread--but not whole grain bread--gained significant weight.

Alcohol may also be a problem. As a plant-centered diet, adherence to a Mediterranean diet is associated with lower cancer risk, but does not appear to lower breast cancer risk. With all the fruits, veggies, nuts, seeds, beans and low saturated fat content, you'd assume there would be lower breast cancer risk, but alcohol is a known breast carcinogen, even in moderate amounts. When researchers created a special adapted version of the Mediterranean diet score that excluded alcohol, the diet does indeed appear to reduce breast cancer risk.

The wonderful grape phytonutrients in red wine can improve our arterial function such that if you drink nonalcoholic red wine (wine with the alcohol removed), you get a significant boost in endothelial function--the ability of our arteries to relax and dilate normally, increasing blood flow. If you drink the same red wine with alcohol, it abolishes the beneficial effect and counteracts the benefit of the grape phytonutrients. So, it would be better just to eat grapes. You can find more information about this in my video Improving on the Mediterranean Diet.

Similarly, there are components of extra virgin olive oil--the antioxidant phytonutrients, that may help endothelial function, but when consumed as oil, (even extra virgin olive oil), it may impair arterial function. So even if white bread dipped in olive oil is the very symbol of the Mediterranean diet, we can modernize it by removing oils and refined grains.

Another important, albeit frequently ignored issue in the modern Mediterranean diet is sodium intake. Despite evidence linking salt intake to high blood pressure, heart disease and strokes, dietary salt intake in the U.S. is on the rise. Right now, Americans get about seven to ten grams a day, mostly from processed foods. If we were to decrease that just by three grams every year, we could possibly save tens of thousands of people from having a heart attack, prevent tens of thousands of strokes, and tens of thousands of deaths. There is a common misperception that only certain people should reduce their salt intake and that for the vast majority of the population, salt reduction is unnecessary, but in reality, the opposite is true.

There is much we can learn from the traditional Mediterranean diet. A defining characteristic of the Mediterranean diet is an abundance of plant foods, but one thing that seems to have fallen by the wayside. No main Mediterranean meal is replete without lots of greens, a key part of not only a good Mediterranean diet, but of any good diet.

Here are some of my previous videos on the Mediterranean diet:

I touch more on whole grains in How Many Meet the Simple Seven? and Whole Grains May Work As Well As Drugs.

More on breast cancer and alcohol in Breast Cancer and Alcohol: How Much Is Safe?, Preventing Skin Cancer From the Inside Out, and Breast Cancer Risk: Red Wine v. White Wine.

I've touched on olive oil in the other videos in this Mediterranean diet series, but also have an older video Extra Virgin Olive Oil vs. Nuts and more recently, Olive Oil & Artery Function.

More on sodium in Dietary Guidelines: With a Grain of Big Salt, Big Salt - Getting to the Meat of the Matter, and Can Diet Protect Against Kidney Cancer? But what if without salt everything tastes like cardboard? Not to worry! See Changing Our Taste Buds.

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: Sally Plank / Flickr. This image has been modified.

Original Link

Four Ways to Improve on the Mediterranean Diet

Improving on the Mediterranean Diet.jpg

The traditional Mediterranean diet can be considered mainly, but not exclusively, as a plant-based diet, and certainly not a whole foods, plant-based diet. Olive oil and wine can be considered essentially fruit juices. Even if one is eating a "vegiterranean diet," an entirely plant-based version, there are a number of problematic nutritional aspects that are rarely talked about. For example, the Mediterranean diet includes lots of white bread, white pasta and not a lot of whole grains.

In an anatomy of the health effects of the Mediterranean diet, the single most important component was the high consumption of plant foods. In contrast, high cereal consumption, meaning high grain consumption, did not appear to help. This may be because most grains that modern Mediterranean dieters eat are refined, like white bread, whereas the traditional Mediterranean diet was characterized by unprocessed cereals--in other words, whole grains. And while whole grains have been associated with lower risk of diabetes, heart disease and cancer, refined grain may increase the risk of diabetes, obesity, heart disease and other chronic diseases. In the PREDIMED study, those who ate the most white bread--but not whole grain bread--gained significant weight.

Alcohol may also be a problem. As a plant-centered diet, adherence to a Mediterranean diet is associated with lower cancer risk, but does not appear to lower breast cancer risk. With all the fruits, veggies, nuts, seeds, beans and low saturated fat content, you'd assume there would be lower breast cancer risk, but alcohol is a known breast carcinogen, even in moderate amounts. When researchers created a special adapted version of the Mediterranean diet score that excluded alcohol, the diet does indeed appear to reduce breast cancer risk.

The wonderful grape phytonutrients in red wine can improve our arterial function such that if you drink nonalcoholic red wine (wine with the alcohol removed), you get a significant boost in endothelial function--the ability of our arteries to relax and dilate normally, increasing blood flow. If you drink the same red wine with alcohol, it abolishes the beneficial effect and counteracts the benefit of the grape phytonutrients. So, it would be better just to eat grapes. You can find more information about this in my video Improving on the Mediterranean Diet.

Similarly, there are components of extra virgin olive oil--the antioxidant phytonutrients, that may help endothelial function, but when consumed as oil, (even extra virgin olive oil), it may impair arterial function. So even if white bread dipped in olive oil is the very symbol of the Mediterranean diet, we can modernize it by removing oils and refined grains.

Another important, albeit frequently ignored issue in the modern Mediterranean diet is sodium intake. Despite evidence linking salt intake to high blood pressure, heart disease and strokes, dietary salt intake in the U.S. is on the rise. Right now, Americans get about seven to ten grams a day, mostly from processed foods. If we were to decrease that just by three grams every year, we could possibly save tens of thousands of people from having a heart attack, prevent tens of thousands of strokes, and tens of thousands of deaths. There is a common misperception that only certain people should reduce their salt intake and that for the vast majority of the population, salt reduction is unnecessary, but in reality, the opposite is true.

There is much we can learn from the traditional Mediterranean diet. A defining characteristic of the Mediterranean diet is an abundance of plant foods, but one thing that seems to have fallen by the wayside. No main Mediterranean meal is replete without lots of greens, a key part of not only a good Mediterranean diet, but of any good diet.

Here are some of my previous videos on the Mediterranean diet:

I touch more on whole grains in How Many Meet the Simple Seven? and Whole Grains May Work As Well As Drugs.

More on breast cancer and alcohol in Breast Cancer and Alcohol: How Much Is Safe?, Preventing Skin Cancer From the Inside Out, and Breast Cancer Risk: Red Wine v. White Wine.

I've touched on olive oil in the other videos in this Mediterranean diet series, but also have an older video Extra Virgin Olive Oil vs. Nuts and more recently, Olive Oil & Artery Function.

More on sodium in Dietary Guidelines: With a Grain of Big Salt, Big Salt - Getting to the Meat of the Matter, and Can Diet Protect Against Kidney Cancer? But what if without salt everything tastes like cardboard? Not to worry! See Changing Our Taste Buds.

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: Sally Plank / Flickr. This image has been modified.

Original Link

Benefits of Nuts for Stroke Prevention

PREDIMED - Does Eating Nuts Prevent Strokes.jpg

In the PREDIMED study, from the Spanish "PREvencio ́n con DIeta MEDiterranea," a whopping 7,447 patients were randomized into three groups. These were folks at high risk for a heart attack, about half were obese, diabetic and most had high blood pressure and high cholesterol, but they had not yet had their first heart attack or stroke. A third were told to eat a Mediterranean diet and given a free quart of extra virgin olive oil every week. The second group were told to eat a Mediterranean diet and given a half pound of free nuts every week, and the last third were told to follow the American Heart Association guidelines and reduce their fat intake. No portion control or exercise advice was given, and they were followed for about five years. The results were published in the New England Journal of Medicine.

The first thing you do when you look at a diet intervention trial is see what the groups actually ended up eating, which can be very different from what they were told to eat. For example, the so-called low-fat group started out at 39 percent of calories from fat, and ended up getting 37 percent of calories from fat, which is high fat even compared to the Standard American Diet which comes in at 33 percent, something the researchers plainly acknowledged. In fact, the control group didn't change much at all over the years, so can be thought of as the what-if-you-don't-do-anything group, which is still an important control group to have. Though the two Mediterranean diet groups didn't get much more Mediterranean. You can see the charts in my video PREDIMED: Does Eating Nuts Prevent Strokes?

The two Mediterranean groups were told to eat more fruits and vegetables, for example, and less meat and dairy, but didn't accomplish any of those compared to control. The biggest changes recorded were, not surprisingly, in the consumption of the freebies. The group that got a free jug of extra-virgin olive oil delivered to their home every week really did start increasing their consumption, in part by replacing some of the refined olive oil they had been using. And those that got a half pound of free nuts sent to them every week for four years straight did start eating more nuts.

Basically the researchers designed a study to test two different Mediterranean diets versus a low fat diet, but ended up studying something very different. In essence, they studied what happens when thousands of people switch from consuming about three tablespoons of olive oil a day (half virgin) to four tablespoons of all virgin, compared to thousands of people who all the sudden go from eating about a half an ounce of nuts a day to a whole ounce, compared to thousands of people who don't make much of a change at all. It may not have been what they were hoping for, but these are important research questions in and of themselves.

With no significant differences in meat and dairy intake, there were no significant differences in saturated fat or cholesterol intake, so no surprise there was no significant differences in their blood cholesterol levels, and so no difference in their subsequent number of heart attacks. In the five or so years the study ran, there were 37 heart attacks in the olive oil group, 31 in the nut group and 38 in the neither group. No significant difference. Same with dying from a heart attack or stroke or from any cause--but, those in the olive oil and especially the nut group had significantly fewer strokes. All three groups were eating stroke-promoting diets; some people in all three groups had strokes after eating these diets for years, and so ideally we'd choose diets that can stop or reverse the disease process, but the diet with added extra virgin olive oil caused about a third fewer strokes, and adding nuts seemed to cut their stroke risk nearly in half. If this worked as well in the general population, in the U.S. alone that would mean preventing 89,000 strokes a year. That's would be like ten strokes an hour around the clock prevented simply by adding half an ounce of nuts to one's daily diet.

Here are some of my previous videos on the Mediterranean diet:

The PREDIMED study got a bad rap because of how it was reported, but it's an extraordinary trial that continues to churn out useful results.

More on nuts in:

But what about nuts and weight gain? See Nuts and Obesity: The Weight of Evidence .

For videos on olive oil, see Extra Virgin Olive Oil vs. Nuts and Olive Oil & Artery Function.

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: Sally Plank / Flickr. This image has been modified.

Original Link

Benefits of Nuts for Stroke Prevention

PREDIMED - Does Eating Nuts Prevent Strokes.jpg

In the PREDIMED study, from the Spanish "PREvencio ́n con DIeta MEDiterranea," a whopping 7,447 patients were randomized into three groups. These were folks at high risk for a heart attack, about half were obese, diabetic and most had high blood pressure and high cholesterol, but they had not yet had their first heart attack or stroke. A third were told to eat a Mediterranean diet and given a free quart of extra virgin olive oil every week. The second group were told to eat a Mediterranean diet and given a half pound of free nuts every week, and the last third were told to follow the American Heart Association guidelines and reduce their fat intake. No portion control or exercise advice was given, and they were followed for about five years. The results were published in the New England Journal of Medicine.

The first thing you do when you look at a diet intervention trial is see what the groups actually ended up eating, which can be very different from what they were told to eat. For example, the so-called low-fat group started out at 39 percent of calories from fat, and ended up getting 37 percent of calories from fat, which is high fat even compared to the Standard American Diet which comes in at 33 percent, something the researchers plainly acknowledged. In fact, the control group didn't change much at all over the years, so can be thought of as the what-if-you-don't-do-anything group, which is still an important control group to have. Though the two Mediterranean diet groups didn't get much more Mediterranean. You can see the charts in my video PREDIMED: Does Eating Nuts Prevent Strokes?

The two Mediterranean groups were told to eat more fruits and vegetables, for example, and less meat and dairy, but didn't accomplish any of those compared to control. The biggest changes recorded were, not surprisingly, in the consumption of the freebies. The group that got a free jug of extra-virgin olive oil delivered to their home every week really did start increasing their consumption, in part by replacing some of the refined olive oil they had been using. And those that got a half pound of free nuts sent to them every week for four years straight did start eating more nuts.

Basically the researchers designed a study to test two different Mediterranean diets versus a low fat diet, but ended up studying something very different. In essence, they studied what happens when thousands of people switch from consuming about three tablespoons of olive oil a day (half virgin) to four tablespoons of all virgin, compared to thousands of people who all the sudden go from eating about a half an ounce of nuts a day to a whole ounce, compared to thousands of people who don't make much of a change at all. It may not have been what they were hoping for, but these are important research questions in and of themselves.

With no significant differences in meat and dairy intake, there were no significant differences in saturated fat or cholesterol intake, so no surprise there was no significant differences in their blood cholesterol levels, and so no difference in their subsequent number of heart attacks. In the five or so years the study ran, there were 37 heart attacks in the olive oil group, 31 in the nut group and 38 in the neither group. No significant difference. Same with dying from a heart attack or stroke or from any cause--but, those in the olive oil and especially the nut group had significantly fewer strokes. All three groups were eating stroke-promoting diets; some people in all three groups had strokes after eating these diets for years, and so ideally we'd choose diets that can stop or reverse the disease process, but the diet with added extra virgin olive oil caused about a third fewer strokes, and adding nuts seemed to cut their stroke risk nearly in half. If this worked as well in the general population, in the U.S. alone that would mean preventing 89,000 strokes a year. That's would be like ten strokes an hour around the clock prevented simply by adding half an ounce of nuts to one's daily diet.

Here are some of my previous videos on the Mediterranean diet:

The PREDIMED study got a bad rap because of how it was reported, but it's an extraordinary trial that continues to churn out useful results.

More on nuts in:

But what about nuts and weight gain? See Nuts and Obesity: The Weight of Evidence .

For videos on olive oil, see Extra Virgin Olive Oil vs. Nuts and Olive Oil & Artery Function.

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: Sally Plank / Flickr. This image has been modified.

Original Link

What’s the Optimal Cholesterol Level?

Optimal Cholesterol Level.jpg

No matter where we live, how old we are or what we look like, health researchers from the Institute of Circulatory and Respiratory Health have discovered that 90% of the chance of having a first heart attack "can be attributed to nine modifiable risk factors." The nine factors that could save our lives include: smoking, too much bad cholesterol, high blood pressure, diabetes, abdominal obesity, stress, a lack of daily fruit and veggie consumption, as well as a lack of daily exercise.

Dr. William Clifford Roberts, Executive Director of Baylor Heart and Vascular Institute and long-time Editor in Chief of the American Journal of Cardiology, is convinced, however, that atherosclerosis has a single cause--namely cholesterol--and that the other so-called atherosclerotic risk factors are only contributory at most. In other words, we could be stressed, overweight, smoking, diabetic couch potatoes, but if our cholesterol is low enough, there may just not be enough cholesterol in our blood stream to infiltrate our artery walls and trigger the disease. Thus, the only absolute prerequisite for a fatal or nonfatal atherosclerotic event like a heart attack is an elevated cholesterol level.

It was not appreciated until recently "that the average blood cholesterol level in the United States, the so-called normal level, was actually abnormal," accelerating the blockages in our arteries and putting a large fraction of the normal population at risk. That's cited as one of the reasons the cholesterol controversy lasted so long--an "unwillingness to accept the notion that a very large fraction of our population actually has an unhealthily high cholesterol level."

Normal cholesterol levels may be fatal cholesterol levels.

The optimal "bad cholesterol" (LDL) level is 50 to 70. Accumulating data from multiple lines of evidence consistently demonstrate that that's where a physiologically normal LDL level would be. That appears to be the threshold above which atherosclerosis and heart attacks develop. That's what we start out at birth with, that's what fellow primates have, and that's the level seen in populations free of the heart disease epidemic. One can also look at all the big randomized controlled cholesterol lowering trials.

In my video, Optimal Cholesterol Level, you can see graphing of the progression of atherosclerosis versus LDL cholesterol. More cholesterol means more atherosclerosis, but if we draw a line down through the points, we can estimate that the LDL level at which there is zero progression is around 70. We can do the same with the studies preventing heart attacks. Zero coronary heart disease events might be reached down around 55, and those who've already had a heart attack and are trying to prevent a second one might need to push LDL levels even lower.

Atherosclerosis is endemic in our population in part because the average person's LDL level is up around 130, approximately twice the normal physiologic level. The reason the federal government doesn't recommend everyone shoot for under 100 is that despite the lower risk accompanying more optimal cholesterol levels, the intensity of clinical intervention required to achieve such levels for everyone in the population would "financially overload the health care system. Drug usage would rise enormously." But, they're assuming drugs are the only way to get our LDL that low. Those eating really healthy plant-based diets may hit the optimal cholesterol target without even trying, naturally nailing under 70.

The reason given by the federal government for not advocating for what the science shows is best was that it might frustrate the public, "who would have difficulty maintaining a lower level," but maybe the public's greatest frustration would come from not being informed of the optimal diet for health.


It's imperative for everyone to understand Dr. Rose's sick population concept, which I introduced in When Low Risk Means High Risk.

What about large fluffy LDL cholesterol versus small and dense? See Does Cholesterol Size Matter?

More from the Framingham Heart Study can be found in Barriers to Heart Disease Prevention and Everything in Moderation? Even Heart Disease?.

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: lightwise © 123RF.com. This image has been modified.

Original Link

What’s the Optimal Cholesterol Level?

Optimal Cholesterol Level.jpg

No matter where we live, how old we are or what we look like, health researchers from the Institute of Circulatory and Respiratory Health have discovered that 90% of the chance of having a first heart attack "can be attributed to nine modifiable risk factors." The nine factors that could save our lives include: smoking, too much bad cholesterol, high blood pressure, diabetes, abdominal obesity, stress, a lack of daily fruit and veggie consumption, as well as a lack of daily exercise.

Dr. William Clifford Roberts, Executive Director of Baylor Heart and Vascular Institute and long-time Editor in Chief of the American Journal of Cardiology, is convinced, however, that atherosclerosis has a single cause--namely cholesterol--and that the other so-called atherosclerotic risk factors are only contributory at most. In other words, we could be stressed, overweight, smoking, diabetic couch potatoes, but if our cholesterol is low enough, there may just not be enough cholesterol in our blood stream to infiltrate our artery walls and trigger the disease. Thus, the only absolute prerequisite for a fatal or nonfatal atherosclerotic event like a heart attack is an elevated cholesterol level.

It was not appreciated until recently "that the average blood cholesterol level in the United States, the so-called normal level, was actually abnormal," accelerating the blockages in our arteries and putting a large fraction of the normal population at risk. That's cited as one of the reasons the cholesterol controversy lasted so long--an "unwillingness to accept the notion that a very large fraction of our population actually has an unhealthily high cholesterol level."

Normal cholesterol levels may be fatal cholesterol levels.

The optimal "bad cholesterol" (LDL) level is 50 to 70. Accumulating data from multiple lines of evidence consistently demonstrate that that's where a physiologically normal LDL level would be. That appears to be the threshold above which atherosclerosis and heart attacks develop. That's what we start out at birth with, that's what fellow primates have, and that's the level seen in populations free of the heart disease epidemic. One can also look at all the big randomized controlled cholesterol lowering trials.

In my video, Optimal Cholesterol Level, you can see graphing of the progression of atherosclerosis versus LDL cholesterol. More cholesterol means more atherosclerosis, but if we draw a line down through the points, we can estimate that the LDL level at which there is zero progression is around 70. We can do the same with the studies preventing heart attacks. Zero coronary heart disease events might be reached down around 55, and those who've already had a heart attack and are trying to prevent a second one might need to push LDL levels even lower.

Atherosclerosis is endemic in our population in part because the average person's LDL level is up around 130, approximately twice the normal physiologic level. The reason the federal government doesn't recommend everyone shoot for under 100 is that despite the lower risk accompanying more optimal cholesterol levels, the intensity of clinical intervention required to achieve such levels for everyone in the population would "financially overload the health care system. Drug usage would rise enormously." But, they're assuming drugs are the only way to get our LDL that low. Those eating really healthy plant-based diets may hit the optimal cholesterol target without even trying, naturally nailing under 70.

The reason given by the federal government for not advocating for what the science shows is best was that it might frustrate the public, "who would have difficulty maintaining a lower level," but maybe the public's greatest frustration would come from not being informed of the optimal diet for health.


It's imperative for everyone to understand Dr. Rose's sick population concept, which I introduced in When Low Risk Means High Risk.

What about large fluffy LDL cholesterol versus small and dense? See Does Cholesterol Size Matter?

More from the Framingham Heart Study can be found in Barriers to Heart Disease Prevention and Everything in Moderation? Even Heart Disease?.

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: lightwise © 123RF.com. This image has been modified.

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

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:

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Flax Seeds Can Have Profound Effect on Hypertension

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A recent article in the journal, Meat Science, acknowledged that a sector of the population perceives meat as a food that is detrimental to their health because of studies associating meat consumption with heart disease and cancer. So, the article continues, meat consumers may look for healthier food alternatives as a means to maintain good health, which represents a good opportunity for the meat industry to develop some new products. The industry felt that natural foods could be added to meat to reach those health-oriented consumers by boosting antioxidants levels, for example. Foods like flax seeds and tomatoes are healthy, associated with reduced risks of cancer and cardiovascular disease. So by making flax-y tomato burgers, they figure they can reduce saturated fat intake and maybe eat less sugar somehow. Wouldn't it be easier to just cut out the middle-cow and eat flax seeds ourselves?

Flax seeds have been described as a "miraculous defense against some critical maladies." I'm a fan of flax, but this title seemed a bit over-exuberant; I figured something just got lost in translation, but then I found a prospective, double-blinded, placebo-controlled, randomized trial--you know how hard that is in a nutrition study? For drugs, it's easy: you have two identical looking pills, one's active, one's placebo, and until the end of the study, neither the researcher nor the patient has any idea which is which, hence "double blind." But people tend to notice what they're eating. So how did they sneak a quarter cup of ground flax seeds into half of the people's diets without them knowing? They created all these various flax or placebo containing foods, and even added bran and molasses to match the color and texture, so it was all a big secret until six months later when they broke the code to see who ate which.

Why test it on hypertension? Because having a systolic blood pressure over 115--that's the top number--may be the single most important determinant for death in the world today. If you take a bunch of older folks, most of them on an array of blood pressure pills, and don't improve their diet at all, despite the drugs, they may start out on average hypertensive and stay hypertensive six months later. But those who were unknowingly eating ground flaxseeds every day, dropped their systolic blood pressure about ten points, and their diastolic, the lower number, by about seven points. That might not sound like a lot, but a drop like that could cut stroke risk 46 percent and heart disease 29 percent, and that ten point drop in the top number could have a similar effect on strokes and heart attacks. And for those that started out over 140, they got a 15-point drop.

In summary, flaxseed induced one of the most potent antihypertensive effects ever achieved by a dietary intervention. In other words, the magnitude of this decrease in blood pressure demonstrated by dietary flaxseed, is as good or better than other nutritional interventions and comparable to many drugs, which can have serious side effects. And they're not exaggerating about the comparable to drugs bit. The flax dropped systolic and diastolic up to 15 and 7. Compare that to powerful ACE inhibitors like Vasotec, which may only drop pressures five and two, and calcium channel blockers like Norvasc or Cardizem which drop pressures eight and three. Side effects of these drugs include a large list of serious medical issues, as seen in my video Flax Seeds for Hypertension, compared to the side effect of flax seeds, "its pleasant nutty flavor."

During the six-month trial there were strokes and heart attacks in both groups, though. Even if the flax seeds can cut risk in half, any avoidable risk is unacceptable. Isn't high blood pressure just inevitable as we get older? No - the prevalence of hypertension does increase dramatically with age, but not for everyone. People who eat more plant-based diets or keep their salt intake low enough tend not to exhibit any change in blood pressure with advancing age. It's always better to prevent the disease in the first place.

And that's not all flax can do. Check out:

Hibiscus tea may help with high blood pressure as well: Hibiscus Tea vs. Plant-Based Diets for Hypertension

Diet can also play an important role in preventing heart disease (How Not to Die from Heart Disease and One in a Thousand: Ending the Heart Disease Epidemic) and diabetes (How Not to Die from Diabetes and Plant-Based Diets and Diabetes). In some cases diet can even reverse some of the worst ravages of high blood pressure: How Not to Die from High Blood Pressure and Kempner Rice Diet: Whipping Us Into Shape.

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:

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What About Eating Just a Little Meat?

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As you can see in my video, Plant-Based Diets and Diabetes, we've known for decades that a plant-based diet may be protective against diabetes. Studies going back half a century found that those eating meat one or more days a week had significantly higher rates of diabetes, and the more frequently meat was eaten, the more frequent the disease. And this is after controlling for weight, so even at the same weight, those eating more plant-based had but a fraction of the diabetes rates. If anything, vegetarians should have had more diabetes just because they appear to live so much longer, so they had more time to develop these kinds of chronic diseases; but no, apparently lower rates of death and disease.

Fast forward 50 years to the Adventist-2 study, looking at 89,000 people, and we see a stepwise drop in the rates of diabetes as one eats more and more plant-based, down to a 78% lower prevalence among those eating strictly plant-based. Protection building incrementally as one moved from eating meat daily, to eating meat weekly, to just fish, to no meat, and then to no eggs and dairy either. Followed over time, vegetarian diets were associated with a substantially lower incidence of diabetes, indicating the potential of these diets to stem the current diabetes epidemic.

We see the same step-wise drop in rates of another leading killer, high blood pressure. The greater the proportion of plant foods, the lower the rates of hypertension, and the same with excess body fat. The only dietary group not on average overweight were those eating diets composed exclusively of plant foods, but again there was the same incremental drop with fewer and fewer animal products. This suggests that it's not black and white, not all or nothing, any steps we can make along this spectrum of eating healthier may accrue significant benefits.

What about eating a really healthy diet with just a little meat? Is it better to eat none at all? We have new insight last year from Taiwan. Asian diets in general tend to be lower in meat and higher in plant foods compared with Western diet, but whether a diet completely avoiding meat and fish would further extend the protective effect of a plant-based diet wasn't known, until now.

Traditionally, Asian populations have had low rates of diabetes, but a diabetes epidemic has since emerged, and appears to coincide with increased meat, animal protein, and animal fat consumption, but the Westernization of Asian diets also brought along a lot of fast food and junk, and so these researchers at the national university didn't want to just compare those eating vegetarian to typical meateaters. So, they compared Bhuddist vegetarians to Bhuddist non-vegetarians, eating traditional Asian diets. Even the omnivores were eating a predominantly plant-based diet, consuming little meat and fish, with the women eating the equivalent of about a single serving a week, and men eating a serving every few days. That's just 8% of the meat intake in the U.S., 3% for the women. The question: is it better to eat 3% or 0%?

Again, both groups were eating healthy; zero soda consumption, for example, in any group. Despite the similarities in their diet, and after controlling for weight, family history, exercise, and smoking, the men eating vegetarian had just half the rates of diabetes, and the vegetarian women just a quarter of the rates. So even in a population consuming a really plant-based diet with little meat and fish, true vegetarians who completely avoided animal flesh, while eating more healthy plant foods, have lower odds for prediabetes and diabetes after accounting for other risk factors. They wanted to break it up into vegan versus ovo-lacto like in the Adventist-2 study, but they couldn't because there were no cases at all of diabetes found within the vegan group.

More on preventing and treating this terrible disease:

The reason I keep going back to that Adventist-2 study is that it's not only the biggest study of those eating plant based diets in North America, but the largest such study anywhere anytime. We owe those investigators a great debt (not to mention the 96,741 participants!). One thing I'm happy my tax dollars are going towards (via the National Cancer Institute and National Institutes of Health). More from the Adventists in Caloric Restriction vs. Animal Protein Restriction.

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.

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