Why Is Milk Consumption Associated with More Bone Fractures?

Why Is Milk Consumption Associated with More Bone Fractures?.jpg

Milk is touted to build strong bones, but a compilation of all the best studies found no association between milk consumption and hip fracture risk, so drinking milk as an adult might not help bones, but what about in adolescence? Harvard researchers decided to put it to the test.

Studies have shown that greater milk consumption during childhood and adolescence contributes to peak bone mass, and is therefore expected to help avoid osteoporosis and bone fractures in later life. But that's not what researchers have found (as you can see in my video Is Milk Good for Our Bones?). Milk consumption during teenage years was not associated with a lower risk of hip fracture, and if anything, milk consumption was associated with a borderline increase in fracture risk in men.

It appears that the extra boost in total body bone mineral density from getting extra calcium is lost within a few years; even if you keep the calcium supplementation up. This suggests a partial explanation for the long-standing enigma that hip fracture rates are highest in populations with the greatest milk consumption. This may be an explanation for why they're not lower, but why would they be higher?

This enigma irked a Swedish research team, puzzled because studies again and again had shown a tendency of a higher risk of fracture with a higher intake of milk. Well, there is a rare birth defect called galactosemia, where babies are born without the enzymes needed to detoxify the galactose found in milk, so they end up with elevated levels of galactose in their blood, which can causes bone loss even as kids. So maybe, the Swedish researchers figured, even in normal people that can detoxify the stuff, it might not be good for the bones to be drinking it every day.

And galactose doesn't just hurt the bones. Galactose is what scientists use to cause premature aging in lab animals--it can shorten their lifespan, cause oxidative stress, inflammation, and brain degeneration--just with the equivalent of like one to two glasses of milk's worth of galactose a day. We're not rats, though. But given the high amount of galactose in milk, recommendations to increase milk intake for prevention of fractures could be a conceivable contradiction. So, the researchers decided to put it to the test, looking at milk intake and mortality as well as fracture risk to test their theory.

A hundred thousand men and women were followed for up to 20 years. Researchers found that milk-drinking women had higher rates of death, more heart disease, and significantly more cancer for each glass of milk. Three glasses a day was associated with nearly twice the risk of premature death, and they had significantly more bone and hip fractures. More milk, more fractures.

Men in a separate study also had a higher rate of death with higher milk consumption, but at least they didn't have higher fracture rates. So, the researchers found a dose dependent higher rate of both mortality and fracture in women, and a higher rate of mortality in men with milk intake, but the opposite for other dairy products like soured milk and yogurt, which would go along with the galactose theory, since bacteria can ferment away some of the lactose. To prove it though, we need a randomized controlled trial to examine the effect of milk intake on mortality and fractures. As the accompanying editorial pointed out, we better find this out soon since milk consumption is on the rise around the world.

What can we do for our bones, then? Weight-bearing exercise such as jumping, weight-lifting, and walking with a weighted vest or backpack may help, along with getting enough calcium (Alkaline Diets, Animal Protein, & Calcium Loss) and vitamin D (Resolving the Vitamin D-Bate). Eating beans (Phytates for the Prevention of Osteoporosis) and avoiding phosphate additives (Phosphate Additives in Meat Purge and Cola) may also help.

Maybe the galactose angle can help explain the findings on prostate cancer (Prostate Cancer and Organic Milk vs. Almond Milk) and Parkinson's disease (Preventing Parkinson's Disease With Diet).

Galactose is a milk sugar. There's also concern about milk proteins (see my casomorphin series) and fats (The Saturated Fat Studies: Buttering Up the Public and Trans Fat in Meat and Dairy) as well as the hormones (Dairy Estrogen and Male Fertility, Estrogen in Meat, Dairy, and Eggs and Why Do Vegan Women Have 5x Fewer Twins?).

Milk might also play a role in diabetes (Does Casein in Milk Trigger Type 1 Diabetes, Does Bovine Insulin in Milk Trigger Type 1 Diabetes?) and breast cancer (Is Bovine Leukemia in Milk Infectious?, The Role of Bovine Leukemia Virus in Breast Cancer, and Industry Response to Bovine Leukemia Virus in Breast Cancer).

In health,

Michael Greger, M.D.

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

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

Benefits of Nuts for Stroke Prevention

PREDIMED - Does Eating Nuts Prevent Strokes.jpg

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

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

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

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

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

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

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

More on nuts in:

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

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

In health,

Michael Greger, M.D.

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

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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.

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

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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:

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