What Do All the Blue Zones Have in Common?

Do Flexitarians Live Longer.jpg

What accounts for the benefits of a Mediterranean-style diet? An anatomy of health effects was published, and the single most important component was the high consumption of plant foods. In contrast, fish and seafood consumption, the only animal foods promoted in the Mediterranean diet, did not seem to help.

If you look at four of the major dietary quality scoring systems, which have all been associated with extending lifespan and lowering heart disease and cancer mortality, they all share only four things in common: more fruit, more vegetables, more whole grains and more nuts and beans. They are all built on a common core of a diet rich in plant foods, whereas opposite food patterns, rich in animal foods and poor in plant-based foods (in other words, the Western diet), is associated with higher risks. So we need to optimize the food environment to support whole grains, vegetables, fruit and plant-based proteins.

That's one of the things all the so-called Blue Zones have in common: the longest living populations have not only social support and engagement and daily exercise, but nutritionally they all center their diets around plant foods, reserving meat mostly for special occasions. In fact, the population with perhaps the highest life-expectancy in the world, the California Adventist vegetarians, doesn't eat any meat at all.

So if the primary benefits of the Mediterranean diet are due to all the whole plant foods, what if you went back to the famous PREDIMED study and created a "provegetarian" scoring system? We know vegetarians live longer, but because a pure vegetarian diet might not easily be embraced by many individuals, maybe it would be easier to swallow if we just tell people more plant-based foods and less animal-based foods. But would just moving along the spectrum towards more plants actually enable people to live longer? Researchers thought of this food pattern as a "gentle approach" to vegetarianism, figuring that if it improved survival it would be an easily understandable message for health promotion: more plant foods, less animal foods.

On this scoring system, you get points for eating fruit, vegetables, nuts, grains, beans, olive oil and potatoes, but get docked points for any animal fats, eggs, fish, dairy or any type of meat or meat products. Of course that means you get a higher score the more potato chips and French fries you eat. That's why I prefer the term "whole-food, plant-based diet" since it's defined by what you eat, not by what you don't eat. When I taught at Cornell I had "vegan" students who apparently were trying to live off French fries and beer; vegan does not necessarily mean health-promoting.

But did the provegetarian scoring system work? Regardless of healthy versus unhealthy, if you give points to people for any kind of plant food, processed or not, and detract points for any kind of animal product consumption, people with higher scores live longer. The maximum provegetarian score is 60, but even just scoring 40 or more was associated with a 40 percent drop in mortality. In fact, there were so few deaths in the highest category of adherence to the provegetarian diet, they had to merge the two upper categories for their analysis. This is evidence that simple advice to increase the consumption of plant-derived foods with reductions in the consumption of foods from animal sources confers a survival advantage. You can view the graph in my video Do Flexitarians Live Longer?

The researchers conclude, "this modest change is realistic, affordable, and achievable because a sizable proportion of their population was already eating that way. So one can get significant survival benefit without a radical shift to the exclusive consumption of plant foods, a more gradual and gentle approach which is more easily translatable into public policy." A 41 percent drop in mortality rates in the United States would mean saving the lives of hundreds of thousands of Americans every year.

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

I've done a few videos on the health of so-called semi-vegetarians or flexitarians ("flexible" vegetarians). See how they rate in:

The Provegetarian Score reminds me of the animal to vegetable protein ratio in Prostate Cancer Survival: The A/V Ratio. My favorite dietary quality index is the one in Calculate Your Healthy Eating Score. How do you rate? Even the healthiest among us may be able to continue to push the envelope.

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 Do All the Blue Zones Have in Common?

Do Flexitarians Live Longer.jpg

What accounts for the benefits of a Mediterranean-style diet? An anatomy of health effects was published, and the single most important component was the high consumption of plant foods. In contrast, fish and seafood consumption, the only animal foods promoted in the Mediterranean diet, did not seem to help.

If you look at four of the major dietary quality scoring systems, which have all been associated with extending lifespan and lowering heart disease and cancer mortality, they all share only four things in common: more fruit, more vegetables, more whole grains and more nuts and beans. They are all built on a common core of a diet rich in plant foods, whereas opposite food patterns, rich in animal foods and poor in plant-based foods (in other words, the Western diet), is associated with higher risks. So we need to optimize the food environment to support whole grains, vegetables, fruit and plant-based proteins.

That's one of the things all the so-called Blue Zones have in common: the longest living populations have not only social support and engagement and daily exercise, but nutritionally they all center their diets around plant foods, reserving meat mostly for special occasions. In fact, the population with perhaps the highest life-expectancy in the world, the California Adventist vegetarians, doesn't eat any meat at all.

So if the primary benefits of the Mediterranean diet are due to all the whole plant foods, what if you went back to the famous PREDIMED study and created a "provegetarian" scoring system? We know vegetarians live longer, but because a pure vegetarian diet might not easily be embraced by many individuals, maybe it would be easier to swallow if we just tell people more plant-based foods and less animal-based foods. But would just moving along the spectrum towards more plants actually enable people to live longer? Researchers thought of this food pattern as a "gentle approach" to vegetarianism, figuring that if it improved survival it would be an easily understandable message for health promotion: more plant foods, less animal foods.

On this scoring system, you get points for eating fruit, vegetables, nuts, grains, beans, olive oil and potatoes, but get docked points for any animal fats, eggs, fish, dairy or any type of meat or meat products. Of course that means you get a higher score the more potato chips and French fries you eat. That's why I prefer the term "whole-food, plant-based diet" since it's defined by what you eat, not by what you don't eat. When I taught at Cornell I had "vegan" students who apparently were trying to live off French fries and beer; vegan does not necessarily mean health-promoting.

But did the provegetarian scoring system work? Regardless of healthy versus unhealthy, if you give points to people for any kind of plant food, processed or not, and detract points for any kind of animal product consumption, people with higher scores live longer. The maximum provegetarian score is 60, but even just scoring 40 or more was associated with a 40 percent drop in mortality. In fact, there were so few deaths in the highest category of adherence to the provegetarian diet, they had to merge the two upper categories for their analysis. This is evidence that simple advice to increase the consumption of plant-derived foods with reductions in the consumption of foods from animal sources confers a survival advantage. You can view the graph in my video Do Flexitarians Live Longer?

The researchers conclude, "this modest change is realistic, affordable, and achievable because a sizable proportion of their population was already eating that way. So one can get significant survival benefit without a radical shift to the exclusive consumption of plant foods, a more gradual and gentle approach which is more easily translatable into public policy." A 41 percent drop in mortality rates in the United States would mean saving the lives of hundreds of thousands of Americans every year.

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

I've done a few videos on the health of so-called semi-vegetarians or flexitarians ("flexible" vegetarians). See how they rate in:

The Provegetarian Score reminds me of the animal to vegetable protein ratio in Prostate Cancer Survival: The A/V Ratio. My favorite dietary quality index is the one in Calculate Your Healthy Eating Score. How do you rate? Even the healthiest among us may be able to continue to push the envelope.

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

The Two Most Active Ingredients of the Mediterranean Diet

Which Parts of the Mediterranean Diet Extended Life.jpg

Olives and nuts are plant foods, and as such, are packed with antioxidants, raising the antioxidant level of our bloodstream resulting in lower fat oxidation and free radical DNA damage, but what's happening inside people's arteries?

Researchers measured the amount of atherosclerotic plaque in the neck arteries going to the brain in folks who for years were eating added nuts, added extra virgin olive oil or neither to their daily diets. In the control group, the plaque got worse, which is what happens when one continues to eat an artery-clogging diet, but there were no significant changes in the added extra virgin olive oil group, and the plaque in the added nut group appeared to get better. The nuts appeared to induce a regression of the disease, or at least a significant delay in the progression. The nut group was still suffering strokes, but only half as many, perhaps because the reduction in plaque height within the arteries on extra nuts was indicating a stabilization of the plaque, rendering them less likely to rupture. You can see these results in my video Which Parts of the Mediterranean Diet Extended Life?

Adding nuts to our diet may also improve endothelial function, boosting the ability of our arteries to dilate naturally by about 30 percent. If you look at the baseline adherence to Mediterranean diet principles and control for things like smoking and exercise, there were only two factors significantly associated with reduced heart attack and stroke risk: more vegetables and more nuts. No significant association with the olive oil, wine, fish or cutting back on soda and cookies. Among the individual components, only increased consumption of vegetables and nuts were related to reduced cardiovascular events.

On the one hand, cutting stroke risk in half just by eating a handful of nuts a day is pretty amazing, but those in the added nut group didn't appear to live any longer overall. This is in contrast to other studies that suggested that frequent nut consumption may extend life. For example, the Harvard health professionals studies, involving a whopping three million person-years of follow-up over decades, found nut consumption associated with fewer deaths from cancer, heart disease, respiratory disease and most importantly fewer deaths overall. This was confirmed by all the other big major prospective studies in a recent review.

So what's going on here with the study showing no longevity benefit from nuts? Did they just not wait long enough? Just because people were randomized to the nut group didn't mean they actually ate more nuts, and those randomized to the other groups didn't necessarily stay away.

If you re-analyze the data comparing the death rates of those who actually ate more nuts to those who actually didn't, nut consumption was indeed associated with significantly reduced risk of death. If you do the same kind of post hoc analysis with olive oil, even with the extra virgin, there is no benefit in terms of living longer. This is consistent with how Ancel Keys, the so-called Father of the Mediterranean diet, viewed olive oil. He thought of its benefit more as a way of just replacing animal fats; anything to get people to eat less lard and butter.

What is the best kind of nut? The greatest benefits were attributed to walnuts, particularly for preventing cancer deaths. Those eating more than three servings of walnuts a week appeared to cut their risk of dying from cancer in half.

Now it's just a matter of communicating the research to the public. All the major cancer groups emphasize a more plant-based diet, remarkably consistent with the World Health Organization guidelines for healthy eating. The far-reaching positive effects of a plant-based diet--including walnuts--may be the most critical message for the public.

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

Think the effects of adding a few nuts to one's daily diet are too good to believe? Check out my video Four Nuts Once a Month. For more on Walnuts and Artery Function check out the video, and for more on nuts and cancer prevention, see Which Nut Fights Cancer Better?

Nuts May Help Prevent Death and so may beans; see Increased Lifespan from Beans. What about Fruits and Longevity: How Many Minutes per Mouthful?

More on protecting ourselves from "brain attacks" in Preventing Strokes with Diet.

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: garlandcannon / Flickr. This image has been modified.

Original Link

The Two Most Active Ingredients of the Mediterranean Diet

Which Parts of the Mediterranean Diet Extended Life.jpg

Olives and nuts are plant foods, and as such, are packed with antioxidants, raising the antioxidant level of our bloodstream resulting in lower fat oxidation and free radical DNA damage, but what's happening inside people's arteries?

Researchers measured the amount of atherosclerotic plaque in the neck arteries going to the brain in folks who for years were eating added nuts, added extra virgin olive oil or neither to their daily diets. In the control group, the plaque got worse, which is what happens when one continues to eat an artery-clogging diet, but there were no significant changes in the added extra virgin olive oil group, and the plaque in the added nut group appeared to get better. The nuts appeared to induce a regression of the disease, or at least a significant delay in the progression. The nut group was still suffering strokes, but only half as many, perhaps because the reduction in plaque height within the arteries on extra nuts was indicating a stabilization of the plaque, rendering them less likely to rupture. You can see these results in my video Which Parts of the Mediterranean Diet Extended Life?

Adding nuts to our diet may also improve endothelial function, boosting the ability of our arteries to dilate naturally by about 30 percent. If you look at the baseline adherence to Mediterranean diet principles and control for things like smoking and exercise, there were only two factors significantly associated with reduced heart attack and stroke risk: more vegetables and more nuts. No significant association with the olive oil, wine, fish or cutting back on soda and cookies. Among the individual components, only increased consumption of vegetables and nuts were related to reduced cardiovascular events.

On the one hand, cutting stroke risk in half just by eating a handful of nuts a day is pretty amazing, but those in the added nut group didn't appear to live any longer overall. This is in contrast to other studies that suggested that frequent nut consumption may extend life. For example, the Harvard health professionals studies, involving a whopping three million person-years of follow-up over decades, found nut consumption associated with fewer deaths from cancer, heart disease, respiratory disease and most importantly fewer deaths overall. This was confirmed by all the other big major prospective studies in a recent review.

So what's going on here with the study showing no longevity benefit from nuts? Did they just not wait long enough? Just because people were randomized to the nut group didn't mean they actually ate more nuts, and those randomized to the other groups didn't necessarily stay away.

If you re-analyze the data comparing the death rates of those who actually ate more nuts to those who actually didn't, nut consumption was indeed associated with significantly reduced risk of death. If you do the same kind of post hoc analysis with olive oil, even with the extra virgin, there is no benefit in terms of living longer. This is consistent with how Ancel Keys, the so-called Father of the Mediterranean diet, viewed olive oil. He thought of its benefit more as a way of just replacing animal fats; anything to get people to eat less lard and butter.

What is the best kind of nut? The greatest benefits were attributed to walnuts, particularly for preventing cancer deaths. Those eating more than three servings of walnuts a week appeared to cut their risk of dying from cancer in half.

Now it's just a matter of communicating the research to the public. All the major cancer groups emphasize a more plant-based diet, remarkably consistent with the World Health Organization guidelines for healthy eating. The far-reaching positive effects of a plant-based diet--including walnuts--may be the most critical message for the public.

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

Think the effects of adding a few nuts to one's daily diet are too good to believe? Check out my video Four Nuts Once a Month. For more on Walnuts and Artery Function check out the video, and for more on nuts and cancer prevention, see Which Nut Fights Cancer Better?

Nuts May Help Prevent Death and so may beans; see Increased Lifespan from Beans. What about Fruits and Longevity: How Many Minutes per Mouthful?

More on protecting ourselves from "brain attacks" in Preventing Strokes with Diet.

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: garlandcannon / Flickr. This image has been modified.

Original Link

The Mediterranean Diet or a Whole Food Plant-Based Diet?

The Mediterranean Diet or a Whole Food Plant-Based Diet.jpg

Recent studies have shown that higher Mediterranean diet adherence scores are associated with a significant reduction of the risk of death, heart disease, cancer, and brain disease. The problem with population studies like these is that people who eat healthier may also live healthier, and so how do we know it's their diet? I examine this in The Mediterranean Diet or a Whole Food Plant-Based Diet?.

As the American Heart Association position states, "Before advising people to follow a Mediterranean diet, we need more studies to find out whether the diet itself or other lifestyle factors account for the lower deaths from heart disease." How do you do that? There are ways you can control for obvious things like smoking and exercise--which many of the studies did--but ideally you'd do an interventional trial, the gold standard of nutritional science. You change people's diets while trying to keep everything else the same and see what happens.

We got that kind of trial 20 years ago with the famous Lyon Diet Heart Study where about 600 folks who had just had their first heart attack were randomized into two groups. The control group received no dietary advice, apart whatever their doctors were telling them, while the experimental group was told to eat more of a Mediterranean-type diet, supplemented with a canola-oil based spread to give them the plant-based omega-3's they'd normally be getting from weeds and walnuts if they actually lived on a Greek isle in the 1950's.

The Mediterranean diet group did end up taking some of the dietary advice to heart. They ate more bread, more fruit, less deli meat, less meat in general, and less butter and cream; other than that, no significant changes in diet were reported in terms of wine, olive oil, or fish consumption. So, they ate less saturated fat and cholesterol, more plant-based omega 3's, but didn't have huge dietary changes. Even so, at the end of about four years, 44 individuals from the control group had a second heart attack, either fatal or nonfatal, but only 14 suffered another attack in the group that changed their diet. So they went from having a 4% chance of having a heart attack every year down to 1%.

A cynic might say that while there was less death and disease, the Mediterranean diet continued to feed their heart disease, so much so that 14 of them suffered new heart attacks while on the diet. Yes, their disease progressed a lot less than the regular diet group (about four times less), but what if there was a diet that could stop or reverse heart disease?

Dr. Caldwell Esselstyn and colleagues at the Cleveland Clinic recently published a case series of 198 consecutive patients with cardiovascular disease counseled to switch to a diet composed entirely of whole plant foods. Of the 198, 177 stuck to the diet, whereas the other 21 fell off the wagon, setting up kind of a natural experiment. What happened to the 21? This was such a sick group of patients that more than half suffered from either a fatal heart attack or needed angioplasty or a heart transplant. In that same time period of about four years, of the 177 that stuck to the plant-based diet, only one had a major event as a result of worsening disease. As Dean Ornish noted in his response to the latest trial, "a Mediterranean diet is better than what most people are consuming"...but even better may be a diet based on whole plant foods.

Dr. Esselstyn's was not a randomized trial, so it can't be directly compared to the Lyon study, and it included very determined patients. Not everyone is willing to dramatically change their diets, even if it may literally be a matter of life or death. In which case, rather than doing nothing, eating a more Mediterranean-type diet may cut risk for heart attack survivors by about two-thirds. Cutting 99% of risk would be better if Esselstyn's results were replicated in a controlled trial, but even a 70% drop in risk could save tens of thousands of lives every year.

For more on the Mediterranean diet, check out:

For more on Dr. Esselstyn's amazing work:

If the short-chain plant-based omega-3s in flax seeds and walnuts appear so beneficial, what about the long-chain omega-3's found in fish and fish oil? There are pros and cons. See, for example, Mercury vs. Omega-3s for Brain Development, Is Fish Oil Just Snake Oil?, and Omega-3's and the Eskimo Fish Tale.

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: wildpixel / Thinkstock. This image has been modified.

Original Link

The Mediterranean Diet or a Whole Food Plant-Based Diet?

The Mediterranean Diet or a Whole Food Plant-Based Diet.jpg

Recent studies have shown that higher Mediterranean diet adherence scores are associated with a significant reduction of the risk of death, heart disease, cancer, and brain disease. The problem with population studies like these is that people who eat healthier may also live healthier, and so how do we know it's their diet? I examine this in The Mediterranean Diet or a Whole Food Plant-Based Diet?.

As the American Heart Association position states, "Before advising people to follow a Mediterranean diet, we need more studies to find out whether the diet itself or other lifestyle factors account for the lower deaths from heart disease." How do you do that? There are ways you can control for obvious things like smoking and exercise--which many of the studies did--but ideally you'd do an interventional trial, the gold standard of nutritional science. You change people's diets while trying to keep everything else the same and see what happens.

We got that kind of trial 20 years ago with the famous Lyon Diet Heart Study where about 600 folks who had just had their first heart attack were randomized into two groups. The control group received no dietary advice, apart whatever their doctors were telling them, while the experimental group was told to eat more of a Mediterranean-type diet, supplemented with a canola-oil based spread to give them the plant-based omega-3's they'd normally be getting from weeds and walnuts if they actually lived on a Greek isle in the 1950's.

The Mediterranean diet group did end up taking some of the dietary advice to heart. They ate more bread, more fruit, less deli meat, less meat in general, and less butter and cream; other than that, no significant changes in diet were reported in terms of wine, olive oil, or fish consumption. So, they ate less saturated fat and cholesterol, more plant-based omega 3's, but didn't have huge dietary changes. Even so, at the end of about four years, 44 individuals from the control group had a second heart attack, either fatal or nonfatal, but only 14 suffered another attack in the group that changed their diet. So they went from having a 4% chance of having a heart attack every year down to 1%.

A cynic might say that while there was less death and disease, the Mediterranean diet continued to feed their heart disease, so much so that 14 of them suffered new heart attacks while on the diet. Yes, their disease progressed a lot less than the regular diet group (about four times less), but what if there was a diet that could stop or reverse heart disease?

Dr. Caldwell Esselstyn and colleagues at the Cleveland Clinic recently published a case series of 198 consecutive patients with cardiovascular disease counseled to switch to a diet composed entirely of whole plant foods. Of the 198, 177 stuck to the diet, whereas the other 21 fell off the wagon, setting up kind of a natural experiment. What happened to the 21? This was such a sick group of patients that more than half suffered from either a fatal heart attack or needed angioplasty or a heart transplant. In that same time period of about four years, of the 177 that stuck to the plant-based diet, only one had a major event as a result of worsening disease. As Dean Ornish noted in his response to the latest trial, "a Mediterranean diet is better than what most people are consuming"...but even better may be a diet based on whole plant foods.

Dr. Esselstyn's was not a randomized trial, so it can't be directly compared to the Lyon study, and it included very determined patients. Not everyone is willing to dramatically change their diets, even if it may literally be a matter of life or death. In which case, rather than doing nothing, eating a more Mediterranean-type diet may cut risk for heart attack survivors by about two-thirds. Cutting 99% of risk would be better if Esselstyn's results were replicated in a controlled trial, but even a 70% drop in risk could save tens of thousands of lives every year.

For more on the Mediterranean diet, check out:

For more on Dr. Esselstyn's amazing work:

If the short-chain plant-based omega-3s in flax seeds and walnuts appear so beneficial, what about the long-chain omega-3's found in fish and fish oil? There are pros and cons. See, for example, Mercury vs. Omega-3s for Brain Development, Is Fish Oil Just Snake Oil?, and Omega-3's and the Eskimo Fish Tale.

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: wildpixel / Thinkstock. This image has been modified.

Original Link

What’s the Mediterranean Diet’s Secret?

Why Was Heart Disease Rare in the Mediterranean?.jpg

The Mediterranean Diet is an "in" topic nowadays in both the medical literature and the lay media. As one researcher put it, "Uncritical laudatory coverage is common, but specifics are hard to come by: What is it? Where did it come from? Why is it good? Merits are rarely detailed; possible downsides are never mentioned." So, let's dig in....

After World War II, the government of Greece asked the Rockefeller foundation to come in and assess the situation. Impressed by the low rates of heart disease in the region, nutrition scientist Ancel Keys--after which "K" rations were named--initiated his famous seven countries study. In this study, he found the rate of fatal heart disease on the Greek isle of Crete was 20 times lower than in the United States. They also had the lowest cancer rates and fewest deaths overall. What were they eating? Their diets were more than 90% plant-based, which may explain why coronary heart disease was such a rarity. A rarity, that is, except for a small class of rich people whose diet differed from that of the general population--they ate meat every day instead of every week or two.

So, the heart of the Mediterranean diet is mainly plant-based, and low in meat and dairy, which Keys considered the "major villains in the diet" because of their saturated fat content. Unfortunately, no one is really eating the traditional Mediterranean diet anymore, even in the Mediterranean. The prevalence of coronary heart disease skyrocketed by an order of magnitude within a few decades in Crete, blamed on the increased consumption of meat and cheese at the expense of plant foods.

Everyone is talking about the Mediterranean diet, but few do it properly. People think of pizza or spaghetti with meat sauce, but while "Italian restaurants brag about the healthy measuring in diet, they serve a travesty of it." If no one's really eating this way anymore, how do you study it?

Researchers came up with a variety of Mediterranean diet adherence scoring systems to see if people who are eating more Mediterranean-ish do better. You get maximum points the more plant foods you eat, and effectively you get points deducted by eating just a single serving of meat or dairy a day. So it's no surprise those that eat relatively higher on the scale have a lower risk of heart disease, cancer, and death overall. After all, the Mediterranean diet can be considered to be a "near vegetarian" diet. "As such, it should be expected to produce the well-established health benefits of vegetarian diets." That is, less heart disease, cancer, death, and inflammation; improved arterial function; a lower risk of developing type 2 diabetes; a reduced risk for stroke, depression, and cognitive impairment.

How might it work? I've talked about the elegant studies showing that those who eat plant-based diets have more plant-based compounds, like aspirin, circulating within their systems. Polyphenol phytonutrients in plant foods are associated with a significantly lower risk of dying. Magnesium consumption is also associated with a significantly lower risk of dying, and is found in dark green leafy vegetables, as well as fruits, beans, nuts, soy, and whole grains.

Heme iron, on the other hand--the iron found in blood and muscle--acts as a pro-oxidant and appears to increase the risk of diabetes, whereas plant-based, non-heme iron appears safe. Similarly, with heart disease, animal-based iron was found to significantly increase the risk of coronary heart disease, our number one killer, but not plant-based iron. The Mediterranean diet is protective compared to the Standard American Diet--no question--but any diet rich in whole plant foods and low in animal-fat consumption could be expected to confer protection against many of our leading killers.

Here are some more videos on the Mediterranean Diet:

For more information on heme iron, see Risk Associated With Iron Supplements.

More on magnesium is found in How Do Nuts Prevent Sudden Cardiac Death? and Mineral of the Year--Magnesium.

And more on polyphenols can be seen in videos like How to Slow Brain Aging by Two Years and Juicing Removes More Than Just Fiber.

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: Couleur / Pixabay. This image has been modified.

Original Link

What’s the Mediterranean Diet’s Secret?

Why Was Heart Disease Rare in the Mediterranean?.jpg

The Mediterranean Diet is an "in" topic nowadays in both the medical literature and the lay media. As one researcher put it, "Uncritical laudatory coverage is common, but specifics are hard to come by: What is it? Where did it come from? Why is it good? Merits are rarely detailed; possible downsides are never mentioned." So, let's dig in....

After World War II, the government of Greece asked the Rockefeller foundation to come in and assess the situation. Impressed by the low rates of heart disease in the region, nutrition scientist Ancel Keys--after which "K" rations were named--initiated his famous seven countries study. In this study, he found the rate of fatal heart disease on the Greek isle of Crete was 20 times lower than in the United States. They also had the lowest cancer rates and fewest deaths overall. What were they eating? Their diets were more than 90% plant-based, which may explain why coronary heart disease was such a rarity. A rarity, that is, except for a small class of rich people whose diet differed from that of the general population--they ate meat every day instead of every week or two.

So, the heart of the Mediterranean diet is mainly plant-based, and low in meat and dairy, which Keys considered the "major villains in the diet" because of their saturated fat content. Unfortunately, no one is really eating the traditional Mediterranean diet anymore, even in the Mediterranean. The prevalence of coronary heart disease skyrocketed by an order of magnitude within a few decades in Crete, blamed on the increased consumption of meat and cheese at the expense of plant foods.

Everyone is talking about the Mediterranean diet, but few do it properly. People think of pizza or spaghetti with meat sauce, but while "Italian restaurants brag about the healthy measuring in diet, they serve a travesty of it." If no one's really eating this way anymore, how do you study it?

Researchers came up with a variety of Mediterranean diet adherence scoring systems to see if people who are eating more Mediterranean-ish do better. You get maximum points the more plant foods you eat, and effectively you get points deducted by eating just a single serving of meat or dairy a day. So it's no surprise those that eat relatively higher on the scale have a lower risk of heart disease, cancer, and death overall. After all, the Mediterranean diet can be considered to be a "near vegetarian" diet. "As such, it should be expected to produce the well-established health benefits of vegetarian diets." That is, less heart disease, cancer, death, and inflammation; improved arterial function; a lower risk of developing type 2 diabetes; a reduced risk for stroke, depression, and cognitive impairment.

How might it work? I've talked about the elegant studies showing that those who eat plant-based diets have more plant-based compounds, like aspirin, circulating within their systems. Polyphenol phytonutrients in plant foods are associated with a significantly lower risk of dying. Magnesium consumption is also associated with a significantly lower risk of dying, and is found in dark green leafy vegetables, as well as fruits, beans, nuts, soy, and whole grains.

Heme iron, on the other hand--the iron found in blood and muscle--acts as a pro-oxidant and appears to increase the risk of diabetes, whereas plant-based, non-heme iron appears safe. Similarly, with heart disease, animal-based iron was found to significantly increase the risk of coronary heart disease, our number one killer, but not plant-based iron. The Mediterranean diet is protective compared to the Standard American Diet--no question--but any diet rich in whole plant foods and low in animal-fat consumption could be expected to confer protection against many of our leading killers.

Here are some more videos on the Mediterranean Diet:

For more information on heme iron, see Risk Associated With Iron Supplements.

More on magnesium is found in How Do Nuts Prevent Sudden Cardiac Death? and Mineral of the Year--Magnesium.

And more on polyphenols can be seen in videos like How to Slow Brain Aging by Two Years and Juicing Removes More Than Just Fiber.

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: Couleur / Pixabay. This image has been modified.

Original Link

Striving for Alkaline Pee and Acidic Poo

Stool pH and Colon Cancer.jpg

More than 30 years ago, an idea was put forward that high colonic pH promoted colorectal cancer. A high colonic pH may promote the creation of carcinogens from bile acids, a process that is inhibited once you get below a pH of about 6.5. This is supported by data which shows those at higher risk for colon cancer may have a higher stool pH, and those at lower risk have a low pH. There was a dramatic difference between the two groups, with most of the high risk group over pH 8, and most of the low risk group under pH 6 (see Stool pH and Colon Cancer).

This may help explain the 50-fold lower rates of colon cancer in Africa compared to America. The bacteria we have in our gut depends on what we eat. If we eat lots of fiber, then we preferentially feed the fiber eating bacteria, which give us back all sorts of health promoting substances like short-chain fatty acids that have anti-inflammatory and anti-cancer properties. More of these organic acids were found in the stools of native Africans than African Americans. More acids, so lower pH. Whereas putrefactive bacteria, eating animal protein, are able to increase stool pH by producing alkaline metabolites like ammonia.

The pH of the stools of white versus black children in Africa was compared. Children were chosen because you can more readily sample their stools, particularly the rural black schoolchildren who were eating such high fiber diets--whole grains, legumes, nuts, vegetables, fruits, and wild greens--that 90% of them could produce a stool on demand. Stuffed from head to tail with plants, they could give you a stool sample at any time, just as easy as getting a urine sample. It was hard to even get access to the white kids, though, who were reluctant to participate in such investigations, even though they were given waxed cartons fitted with lids while all the black kids got was a plate and a square of paper towel.

The researchers found significantly lower fecal pH in those eating the traditional, rural plant-based diets compared to those eating the traditional Western diet, who were eating far fewer whole plant foods than the black children. But, remove some of those whole plant foods, like switch their corn for white bread for just a few days and their stool pH goes up, and add whole plant foods like an extra five to seven servings of fruit every day, and their stool pH goes down even further and gets more acidic. It makes sense because when you ferment fruits, veggies, and grains, they turn sour, like vinegar, sauerkraut, or sourdough, because good bacteria like lactobacillus produce organic acids like lactic acid. Those who eat a lot of plants have more of those good bugs. So, using the purple cabbage test highlighted in my video, Testing Your Diet with Pee & Purple Cabbage, we want blue pee, but pink poo.

If you compare the fecal samples of those eating vegetarian or vegan to those eating standard diets, plant-based diets appear to shift the makeup of the bacteria in our gut, resulting in a significantly lower stool pH, and the more plant-based, the lower the pH dropped. It's like a positive feedback loop: fiber-eating bacteria produce the acids to create the pH at which fiber-eating bacteria thrive while suppressing the group of less beneficial bugs.

It might taken even as little as two weeks to bring stool pH down on a plant-based diet. In a study published in the British Journal of Cancer, a dozen volunteers carefully selected for their trustworthiness and randomized to sequentially go on regular, vegetarian, or vegan diets and two weeks in, a significant drop in fecal pH was achieved eating completely plant-based.

But there are differing qualities of plant-based diets. For example, the two groups followed in the study I mentioned earlier had dramatically different stool pH, yet both groups were vegetarian. The high risk group was eating mostly refined grains, very little fiber, whereas the low risk group was eating whole grains and beans, packed with fiber for our fiber-friendly flora to munch on.

Just as a "reduction of high serum cholesterol contributes to the avoidance of coronary heart disease," a fall in the fecal pH value may contribute to the avoidance of bowel cancer and through the same means, eating more whole plant foods.

More on colon cancer prevention in:

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: Kitti Sukhonthanit © 123RF.com. This image has been modified.

Original Link

Striving for Alkaline Pee and Acidic Poo

Stool pH and Colon Cancer.jpg

More than 30 years ago, an idea was put forward that high colonic pH promoted colorectal cancer. A high colonic pH may promote the creation of carcinogens from bile acids, a process that is inhibited once you get below a pH of about 6.5. This is supported by data which shows those at higher risk for colon cancer may have a higher stool pH, and those at lower risk have a low pH. There was a dramatic difference between the two groups, with most of the high risk group over pH 8, and most of the low risk group under pH 6 (see Stool pH and Colon Cancer).

This may help explain the 50-fold lower rates of colon cancer in Africa compared to America. The bacteria we have in our gut depends on what we eat. If we eat lots of fiber, then we preferentially feed the fiber eating bacteria, which give us back all sorts of health promoting substances like short-chain fatty acids that have anti-inflammatory and anti-cancer properties. More of these organic acids were found in the stools of native Africans than African Americans. More acids, so lower pH. Whereas putrefactive bacteria, eating animal protein, are able to increase stool pH by producing alkaline metabolites like ammonia.

The pH of the stools of white versus black children in Africa was compared. Children were chosen because you can more readily sample their stools, particularly the rural black schoolchildren who were eating such high fiber diets--whole grains, legumes, nuts, vegetables, fruits, and wild greens--that 90% of them could produce a stool on demand. Stuffed from head to tail with plants, they could give you a stool sample at any time, just as easy as getting a urine sample. It was hard to even get access to the white kids, though, who were reluctant to participate in such investigations, even though they were given waxed cartons fitted with lids while all the black kids got was a plate and a square of paper towel.

The researchers found significantly lower fecal pH in those eating the traditional, rural plant-based diets compared to those eating the traditional Western diet, who were eating far fewer whole plant foods than the black children. But, remove some of those whole plant foods, like switch their corn for white bread for just a few days and their stool pH goes up, and add whole plant foods like an extra five to seven servings of fruit every day, and their stool pH goes down even further and gets more acidic. It makes sense because when you ferment fruits, veggies, and grains, they turn sour, like vinegar, sauerkraut, or sourdough, because good bacteria like lactobacillus produce organic acids like lactic acid. Those who eat a lot of plants have more of those good bugs. So, using the purple cabbage test highlighted in my video, Testing Your Diet with Pee & Purple Cabbage, we want blue pee, but pink poo.

If you compare the fecal samples of those eating vegetarian or vegan to those eating standard diets, plant-based diets appear to shift the makeup of the bacteria in our gut, resulting in a significantly lower stool pH, and the more plant-based, the lower the pH dropped. It's like a positive feedback loop: fiber-eating bacteria produce the acids to create the pH at which fiber-eating bacteria thrive while suppressing the group of less beneficial bugs.

It might taken even as little as two weeks to bring stool pH down on a plant-based diet. In a study published in the British Journal of Cancer, a dozen volunteers carefully selected for their trustworthiness and randomized to sequentially go on regular, vegetarian, or vegan diets and two weeks in, a significant drop in fecal pH was achieved eating completely plant-based.

But there are differing qualities of plant-based diets. For example, the two groups followed in the study I mentioned earlier had dramatically different stool pH, yet both groups were vegetarian. The high risk group was eating mostly refined grains, very little fiber, whereas the low risk group was eating whole grains and beans, packed with fiber for our fiber-friendly flora to munch on.

Just as a "reduction of high serum cholesterol contributes to the avoidance of coronary heart disease," a fall in the fecal pH value may contribute to the avoidance of bowel cancer and through the same means, eating more whole plant foods.

More on colon cancer prevention in:

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: Kitti Sukhonthanit © 123RF.com. This image has been modified.

Original Link