How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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

How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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

How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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 Not to Add to White Rice, Potatoes, or Pasta

What Not to Add to White Rice, Potatoes, or Pasta.jpeg

Rice currently feeds almost half the human population, making it the single most important staple food in the world, but a meta-analysis of seven cohort studies following 350,000 people for up to 20 years found that higher consumption of white rice was associated with a significantly increased risk of type 2 diabetes, especially in Asian populations. They estimated each serving per day of white rice was associated with an 11% increase in risk of diabetes. This could explain why China has almost the same diabetes rates as we do.

Diabetes rates in China are at about 10%; we're at about 11%, despite seven times less obesity in China. Japan has eight times less obesity than we do, yet may have a higher incidence of newly diagnosed diabetes cases than we do--nine per a thousand compared to our eight. They're skinnier and still may have more diabetes. Maybe it's because of all the white rice they eat.

Eating whole fruit is associated with lower risk of diabetes, whereas eating fruit processed into juice may not just be neutral, but actually increases diabetes risk. In the same way, eating whole grains, like whole wheat bread or brown rice is associated with lower risk of diabetes, whereas eating white rice, a processed grain, may not just be neutral, but actually increase diabetes risk.

White rice consumption does not appear to be associated with increased risk of heart attack or stroke, though, which is a relief after an earlier study in China suggested a connection with stroke. But do we want to eat a food that's just neutral regarding some of our leading causes of death, when we can eat whole foods that are associated with lower risk of diabetes, heart attack, stroke, and weight gain?

If the modern diabetes epidemic in China and Japan has been linked to white rice consumption, how can we reconcile that with low diabetes rates just a few decades ago when they ate even more rice? If you look at the Cornell-Oxford-China Project, rural plant-based diets centered around rice were associated with relatively low risk of the so-called diseases of affluence, which includes diabetes. Maybe Asians just genetically don't get the same blood sugar spike when they eat white rice? This is not the case; if anything people of Chinese ethnicity get higher blood sugar spikes.

The rise in these diseases of affluence in China over the last half century has been blamed in part on the tripling of the consumption of animal source foods. The upsurge in diabetes has been most dramatic, and it's mostly just happened over the last decade. That crazy 9.7% diabetes prevalence figure that rivals ours is new--they appeared to have one of the lowest diabetes rates in the world in the year 2000.

So what happened to their diets in the last 20 years or so? Oil consumption went up 20%, pork consumption went up 40%, and rice consumption dropped about 30%. As diabetes rates were skyrocketing, rice consumption was going down, so maybe it's the animal products and junk food that are the problem. Yes, brown rice is better than white rice, but to stop the mounting Asian epidemic, maybe we should focus on removing the cause--the toxic Western diet. That would be consistent with data showing animal protein and fat consumption associated with increased diabetes risk.

But that doesn't explain why the biggest recent studies in Japan and China associate white rice intake with diabetes. One possibility is that animal protein is making the rice worse. If you feed people mashed white potatoes, a high glycemic food like white rice, you can see in my video If White Rice is Linked to Diabetes, What About China? the level of insulin your pancreas has to pump out to keep your blood sugars in check. But what if you added some tuna fish? Tuna doesn't have any carbs, sugar, or starch so it shouldn't make a difference. Or maybe it would even lower the mashed potato spike by lowering the glycemic load of the whole meal? Instead you get twice the insulin spike. This also happens with white flour spaghetti versus white flour spaghetti with meat. The addition of animal protein makes the pancreas work twice as hard.

You can do it with straight sugar water too. If you do a glucose challenge test to test for diabetes, where you drink a certain amount of sugar and add some meat, you get a much bigger spike than without meat. And the more meat you add, the worse it gets. Just adding a little meat to carbs doesn't seem to do much, but once you get up to around a third of a chicken breast's worth, you can elicit a significantly increased surge of insulin. This may help explain why those eating plant-based have such low diabetes rates, because animal protein can markedly potentiate the insulin secretion triggered by carbohydrate ingestion.

The protein exacerbation of the effect of refined carbs could help explain the remarkable results achieved by Dr. Kempner with a don't-try-this-at-home diet composed of mostly white rice and sugar. See my video, Kempner Rice Diet: Whipping Us Into Shape.

Refined grains may also not be good for our blood pressure (see Whole Grains May Work As Well As Drugs).

What should we be eating to best decrease our risk of diabetes? See:

And check out my summary video, How Not to Die from Diabetes.

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 Not to Add to White Rice, Potatoes, or Pasta

What Not to Add to White Rice, Potatoes, or Pasta.jpeg

Rice currently feeds almost half the human population, making it the single most important staple food in the world, but a meta-analysis of seven cohort studies following 350,000 people for up to 20 years found that higher consumption of white rice was associated with a significantly increased risk of type 2 diabetes, especially in Asian populations. They estimated each serving per day of white rice was associated with an 11% increase in risk of diabetes. This could explain why China has almost the same diabetes rates as we do.

Diabetes rates in China are at about 10%; we're at about 11%, despite seven times less obesity in China. Japan has eight times less obesity than we do, yet may have a higher incidence of newly diagnosed diabetes cases than we do--nine per a thousand compared to our eight. They're skinnier and still may have more diabetes. Maybe it's because of all the white rice they eat.

Eating whole fruit is associated with lower risk of diabetes, whereas eating fruit processed into juice may not just be neutral, but actually increases diabetes risk. In the same way, eating whole grains, like whole wheat bread or brown rice is associated with lower risk of diabetes, whereas eating white rice, a processed grain, may not just be neutral, but actually increase diabetes risk.

White rice consumption does not appear to be associated with increased risk of heart attack or stroke, though, which is a relief after an earlier study in China suggested a connection with stroke. But do we want to eat a food that's just neutral regarding some of our leading causes of death, when we can eat whole foods that are associated with lower risk of diabetes, heart attack, stroke, and weight gain?

If the modern diabetes epidemic in China and Japan has been linked to white rice consumption, how can we reconcile that with low diabetes rates just a few decades ago when they ate even more rice? If you look at the Cornell-Oxford-China Project, rural plant-based diets centered around rice were associated with relatively low risk of the so-called diseases of affluence, which includes diabetes. Maybe Asians just genetically don't get the same blood sugar spike when they eat white rice? This is not the case; if anything people of Chinese ethnicity get higher blood sugar spikes.

The rise in these diseases of affluence in China over the last half century has been blamed in part on the tripling of the consumption of animal source foods. The upsurge in diabetes has been most dramatic, and it's mostly just happened over the last decade. That crazy 9.7% diabetes prevalence figure that rivals ours is new--they appeared to have one of the lowest diabetes rates in the world in the year 2000.

So what happened to their diets in the last 20 years or so? Oil consumption went up 20%, pork consumption went up 40%, and rice consumption dropped about 30%. As diabetes rates were skyrocketing, rice consumption was going down, so maybe it's the animal products and junk food that are the problem. Yes, brown rice is better than white rice, but to stop the mounting Asian epidemic, maybe we should focus on removing the cause--the toxic Western diet. That would be consistent with data showing animal protein and fat consumption associated with increased diabetes risk.

But that doesn't explain why the biggest recent studies in Japan and China associate white rice intake with diabetes. One possibility is that animal protein is making the rice worse. If you feed people mashed white potatoes, a high glycemic food like white rice, you can see in my video If White Rice is Linked to Diabetes, What About China? the level of insulin your pancreas has to pump out to keep your blood sugars in check. But what if you added some tuna fish? Tuna doesn't have any carbs, sugar, or starch so it shouldn't make a difference. Or maybe it would even lower the mashed potato spike by lowering the glycemic load of the whole meal? Instead you get twice the insulin spike. This also happens with white flour spaghetti versus white flour spaghetti with meat. The addition of animal protein makes the pancreas work twice as hard.

You can do it with straight sugar water too. If you do a glucose challenge test to test for diabetes, where you drink a certain amount of sugar and add some meat, you get a much bigger spike than without meat. And the more meat you add, the worse it gets. Just adding a little meat to carbs doesn't seem to do much, but once you get up to around a third of a chicken breast's worth, you can elicit a significantly increased surge of insulin. This may help explain why those eating plant-based have such low diabetes rates, because animal protein can markedly potentiate the insulin secretion triggered by carbohydrate ingestion.

The protein exacerbation of the effect of refined carbs could help explain the remarkable results achieved by Dr. Kempner with a don't-try-this-at-home diet composed of mostly white rice and sugar. See my video, Kempner Rice Diet: Whipping Us Into Shape.

Refined grains may also not be good for our blood pressure (see Whole Grains May Work As Well As Drugs).

What should we be eating to best decrease our risk of diabetes? See:

And check out my summary video, How Not to Die from Diabetes.

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

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

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.

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The Two Most Active Ingredients of the Mediterranean Diet

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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

Benefits of Nuts for Stroke Prevention

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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