Antioxidant- and Folate-Rich Foods for Depression

Antioxidant- and Folate-Rich Foods for Depression.jpeg

According to the Centers for Disease Control and Prevention, the rates of all of our top 10 killers have fallen or stabilized except for one, suicide. As shown in my video, Antioxidants & Depression, accumulating evidence indicates that free radicals may play important roles in the development of various neuropsychiatric disorders including major depression, a common cause of suicide.

In a study of nearly 300,000 Canadians, for example, greater fruit and vegetable consumption was associated with lower odds of depression, psychological distress, self-reported mood and anxiety disorders and poor perceived mental health. They conclude that since a healthy diet comprised of a high intake of fruits and vegetables is rich in anti-oxidants, it may consequently dampen the detrimental effects of oxidative stress on mental health.

But that study was based on asking how many fruits and veggies people ate. Maybe people were just telling the researchers what they thought they wanted to hear. What if you actually measure the levels of carotenoid phytonutrients in people's bloodstreams? The same relationship is found. Testing nearly 2000 people across the United States, researchers found that a higher total blood carotenoid level was indeed associated with a lower likelihood of elevated depressive symptoms, and there appeared to be a dose-response relationship, meaning the higher the levels, the better people felt.

Lycopene, the red pigment predominantly found in tomatoes (but also present in watermelon, pink grapefruit, guava and papaya) is the most powerful carotenoid antioxidant. In a test tube, it's about 100 times more effective at quenching free radicals than a more familiar antioxidant like vitamin E.

Do people who eat more tomatoes have less depression, then? Apparently so. A study of about a thousand older men and women found that those who ate the most tomato products had only about half the odds of depression. The researchers conclude that a tomato-rich diet may have a beneficial effect on the prevention of depressive symptoms.

Higher consumption of fruits and vegetables has been found to lead to a lower risk of developing depression, but if it's the antioxidants can't we just take an antioxidant pill? No.

Only food sources of antioxidants were protectively associated with depression. Not antioxidants from dietary supplements. Although plant foods and food-derived phytochemicals have been associated with health benefits, antioxidants from dietary supplements appear to be less beneficial and may, in fact, be detrimental to health. This may indicate that the form and delivery of the antioxidants are important. Alternatively, the observed associations may be due not to antioxidants but rather to other dietary factors, such as folate, that also occur in plant-rich diets.

In a study of thousands of middle-aged office workers, eating lots of processed food was found to be a risk factor for at least mild to moderate depression five years later, whereas a whole food pattern was found to be protective. Yes, it could be because of the high content of antioxidants in fruits and vegetables but could also be the folate in greens and beans, as some studies have suggested an increased risk of depression in folks who may not have been eating enough.

Low folate levels in the blood are associated with depression, but since most of the early studies were cross-sectional, meaning a snapshot in time, we didn't know if the low folate led to depression or the depression led to low folate. Maybe when you have the blues you don't want to eat the greens.

But since then a number of cohort studies were published, following people over time. They show that a low dietary intake of folate may indeed be a risk factor for severe depression, as much as a threefold higher risk. Note this is for dietary folate intake, not folic acid supplements; those with higher levels were actually eating healthy foods. If you give people folic acid pills they don't seem to work. This may be because folate is found in dark green leafy vegetables like spinach, whereas folic acid is the oxidized synthetic compound used in food fortification and dietary supplements because it's more shelf-stable. It may have different effects on the body as I previously explored in Can Folic Acid Be Harmful?

These kinds of findings point to the importance of antioxidant food sources rather than dietary supplements. But there was an interesting study giving people high dose vitamin C. In contrast to the placebo group, those given vitamin C experienced a decrease in depression scores and also greater FSI. What is FSI? Frequency of Sexual Intercourse.

Evidently, high dose vitamin C improves mood and intercourse frequency, but only in sexual partners that don't live with one another. In the placebo group, those not living together had sex about once a week, and those living together a little higher, once every five days, with no big change on vitamin C. But for those not living together, on vitamin C? Every other day! The differential effect for non-cohabitants suggests that the mechanism is not a peripheral one, meaning outside the brain, but a central one--some psychological change which motivates the person to venture forth to have intercourse. The mild antidepressant effect they found was unrelated to cohabitation or frequency, so it does not appear that the depression scores improved just because of the improved FSI.

For more mental health video, see:

Anything else we can do to enhance our sexual health and attractiveness? See:

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

Antioxidant- and Folate-Rich Foods for Depression

Antioxidant- and Folate-Rich Foods for Depression.jpeg

According to the Centers for Disease Control and Prevention, the rates of all of our top 10 killers have fallen or stabilized except for one, suicide. As shown in my video, Antioxidants & Depression, accumulating evidence indicates that free radicals may play important roles in the development of various neuropsychiatric disorders including major depression, a common cause of suicide.

In a study of nearly 300,000 Canadians, for example, greater fruit and vegetable consumption was associated with lower odds of depression, psychological distress, self-reported mood and anxiety disorders and poor perceived mental health. They conclude that since a healthy diet comprised of a high intake of fruits and vegetables is rich in anti-oxidants, it may consequently dampen the detrimental effects of oxidative stress on mental health.

But that study was based on asking how many fruits and veggies people ate. Maybe people were just telling the researchers what they thought they wanted to hear. What if you actually measure the levels of carotenoid phytonutrients in people's bloodstreams? The same relationship is found. Testing nearly 2000 people across the United States, researchers found that a higher total blood carotenoid level was indeed associated with a lower likelihood of elevated depressive symptoms, and there appeared to be a dose-response relationship, meaning the higher the levels, the better people felt.

Lycopene, the red pigment predominantly found in tomatoes (but also present in watermelon, pink grapefruit, guava and papaya) is the most powerful carotenoid antioxidant. In a test tube, it's about 100 times more effective at quenching free radicals than a more familiar antioxidant like vitamin E.

Do people who eat more tomatoes have less depression, then? Apparently so. A study of about a thousand older men and women found that those who ate the most tomato products had only about half the odds of depression. The researchers conclude that a tomato-rich diet may have a beneficial effect on the prevention of depressive symptoms.

Higher consumption of fruits and vegetables has been found to lead to a lower risk of developing depression, but if it's the antioxidants can't we just take an antioxidant pill? No.

Only food sources of antioxidants were protectively associated with depression. Not antioxidants from dietary supplements. Although plant foods and food-derived phytochemicals have been associated with health benefits, antioxidants from dietary supplements appear to be less beneficial and may, in fact, be detrimental to health. This may indicate that the form and delivery of the antioxidants are important. Alternatively, the observed associations may be due not to antioxidants but rather to other dietary factors, such as folate, that also occur in plant-rich diets.

In a study of thousands of middle-aged office workers, eating lots of processed food was found to be a risk factor for at least mild to moderate depression five years later, whereas a whole food pattern was found to be protective. Yes, it could be because of the high content of antioxidants in fruits and vegetables but could also be the folate in greens and beans, as some studies have suggested an increased risk of depression in folks who may not have been eating enough.

Low folate levels in the blood are associated with depression, but since most of the early studies were cross-sectional, meaning a snapshot in time, we didn't know if the low folate led to depression or the depression led to low folate. Maybe when you have the blues you don't want to eat the greens.

But since then a number of cohort studies were published, following people over time. They show that a low dietary intake of folate may indeed be a risk factor for severe depression, as much as a threefold higher risk. Note this is for dietary folate intake, not folic acid supplements; those with higher levels were actually eating healthy foods. If you give people folic acid pills they don't seem to work. This may be because folate is found in dark green leafy vegetables like spinach, whereas folic acid is the oxidized synthetic compound used in food fortification and dietary supplements because it's more shelf-stable. It may have different effects on the body as I previously explored in Can Folic Acid Be Harmful?

These kinds of findings point to the importance of antioxidant food sources rather than dietary supplements. But there was an interesting study giving people high dose vitamin C. In contrast to the placebo group, those given vitamin C experienced a decrease in depression scores and also greater FSI. What is FSI? Frequency of Sexual Intercourse.

Evidently, high dose vitamin C improves mood and intercourse frequency, but only in sexual partners that don't live with one another. In the placebo group, those not living together had sex about once a week, and those living together a little higher, once every five days, with no big change on vitamin C. But for those not living together, on vitamin C? Every other day! The differential effect for non-cohabitants suggests that the mechanism is not a peripheral one, meaning outside the brain, but a central one--some psychological change which motivates the person to venture forth to have intercourse. The mild antidepressant effect they found was unrelated to cohabitation or frequency, so it does not appear that the depression scores improved just because of the improved FSI.

For more mental health video, see:

Anything else we can do to enhance our sexual health and attractiveness? See:

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

Can You Eat Too Much Fruit?

Can You Eat Too Much Fruit?.jpeg

In my video If Fructose is Bad, What About Fruit?, I explored how adding berries to our meals can actually blunt the detrimental effects of high glycemic foods, but how many berries? The purpose of one study out of Finland was to determine the minimum level of blueberry consumption at which a consumer may realistically expect to receive antioxidant benefits after eating blueberries with a sugary breakfast cereal. If we eat a bowl of corn flakes with no berries, within two hours, so many free radicals are created that it puts us into oxidative debt. The antioxidant power of our bloodstream drops below where we started from before breakfast, as the antioxidants in our bodies get used up dealing with such a crappy breakfast. As you can see in How Much Fruit is Too Much? video, a quarter cup of blueberries didn't seem to help much, but a half cup of blueberries did.

What about fruit for diabetics? Most guidelines recommend eating a diet with a high intake of fiber-rich food, including fruit, because they're so healthy--antioxidants, anti-inflammatory, improving artery function, and reducing cancer risk. However, some health professionals have concerns about the sugar content of fruit and therefore recommend restricting the fruit intake. So let's put it to the test! In a study from Denmark, diabetics were randomized into two groups: one told to eat at least two pieces of fruit a day, and the other told at most, two fruits a day. The reduce fruit group indeed reduce their fruit consumption, but it had no effect on the control of their diabetes or weight, and so, the researchers concluded, the intake of fruit should not be restricted in patients with type 2 diabetes. An emerging literature has shown that low-dose fructose may actually benefit blood sugar control. Having a piece of fruit with each meal would be expected to lower, not raise the blood sugar response.

The threshold for toxicity of fructose may be around 50 grams. The problem is that's the current average adult fructose consumption. So, the levels of half of all adults are likely above the threshold for fructose toxicity, and adolescents currently average 75. Is that limit for added sugars or for all fructose? If we don't want more than 50 and there's about ten in a piece of fruit, should we not eat more than five fruit a day? Quoting from the Harvard Health Letter, "the nutritional problems of fructose and sugar come when they are added to foods. Fruit, on the other hand, is beneficial in almost any amount." What do they mean almost? Can we eat ten fruit a day? How about twenty fruit a day?

It's actually been put to the test.

Seventeen people were made to eat 20 servings a day of fruit. Despite the extraordinarily high fructose content of this diet, presumably about 200 g/d--eight cans of soda worth, the investigators reported no adverse effects (and possible benefit actually) for body weight, blood pressure, and insulin and lipid levels after three to six months. More recently, Jenkins and colleagues put people on about a 20 servings of fruit a day diet for a few weeks and found no adverse effects on weight or blood pressure or triglycerides, and an astounding 38 point drop in LDL cholesterol.

There was one side effect, though. Given the 44 servings of vegetables they had on top of all that fruit, they recorded the largest bowl movements apparently ever documented in a dietary intervention.


Cutting down on sugary foods may be easier said than done (see Are Sugary Foods Addictive?) but it's worth it. For more on the dangers of high levels of fructose in added sugars, see How Much Added Sugar Is Too Much?.

What's that about being in oxidative debt? See my three part series on how to pull yourself out of the red:

Ironically, fat may be more of a problem when it comes to diabetes than sugar, see:

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

Can You Eat Too Much Fruit?

Can You Eat Too Much Fruit?.jpeg

In my video If Fructose is Bad, What About Fruit?, I explored how adding berries to our meals can actually blunt the detrimental effects of high glycemic foods, but how many berries? The purpose of one study out of Finland was to determine the minimum level of blueberry consumption at which a consumer may realistically expect to receive antioxidant benefits after eating blueberries with a sugary breakfast cereal. If we eat a bowl of corn flakes with no berries, within two hours, so many free radicals are created that it puts us into oxidative debt. The antioxidant power of our bloodstream drops below where we started from before breakfast, as the antioxidants in our bodies get used up dealing with such a crappy breakfast. As you can see in How Much Fruit is Too Much? video, a quarter cup of blueberries didn't seem to help much, but a half cup of blueberries did.

What about fruit for diabetics? Most guidelines recommend eating a diet with a high intake of fiber-rich food, including fruit, because they're so healthy--antioxidants, anti-inflammatory, improving artery function, and reducing cancer risk. However, some health professionals have concerns about the sugar content of fruit and therefore recommend restricting the fruit intake. So let's put it to the test! In a study from Denmark, diabetics were randomized into two groups: one told to eat at least two pieces of fruit a day, and the other told at most, two fruits a day. The reduce fruit group indeed reduce their fruit consumption, but it had no effect on the control of their diabetes or weight, and so, the researchers concluded, the intake of fruit should not be restricted in patients with type 2 diabetes. An emerging literature has shown that low-dose fructose may actually benefit blood sugar control. Having a piece of fruit with each meal would be expected to lower, not raise the blood sugar response.

The threshold for toxicity of fructose may be around 50 grams. The problem is that's the current average adult fructose consumption. So, the levels of half of all adults are likely above the threshold for fructose toxicity, and adolescents currently average 75. Is that limit for added sugars or for all fructose? If we don't want more than 50 and there's about ten in a piece of fruit, should we not eat more than five fruit a day? Quoting from the Harvard Health Letter, "the nutritional problems of fructose and sugar come when they are added to foods. Fruit, on the other hand, is beneficial in almost any amount." What do they mean almost? Can we eat ten fruit a day? How about twenty fruit a day?

It's actually been put to the test.

Seventeen people were made to eat 20 servings a day of fruit. Despite the extraordinarily high fructose content of this diet, presumably about 200 g/d--eight cans of soda worth, the investigators reported no adverse effects (and possible benefit actually) for body weight, blood pressure, and insulin and lipid levels after three to six months. More recently, Jenkins and colleagues put people on about a 20 servings of fruit a day diet for a few weeks and found no adverse effects on weight or blood pressure or triglycerides, and an astounding 38 point drop in LDL cholesterol.

There was one side effect, though. Given the 44 servings of vegetables they had on top of all that fruit, they recorded the largest bowl movements apparently ever documented in a dietary intervention.


Cutting down on sugary foods may be easier said than done (see Are Sugary Foods Addictive?) but it's worth it. For more on the dangers of high levels of fructose in added sugars, see How Much Added Sugar Is Too Much?.

What's that about being in oxidative debt? See my three part series on how to pull yourself out of the red:

Ironically, fat may be more of a problem when it comes to diabetes than sugar, see:

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

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

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

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

Lipotoxicity: How Saturated Fat Raises Blood Sugar

NF-Nov24 Lipotoxicity How Saturated Fat Raises Blood Sugar copy.jpg

The reason those eating plant-based diets have less fat buildup in their muscle cells and less insulin resistance may be because saturated fats appear to impair blood sugar control the most.

The association between fat and insulin resistance is now widely accepted. Insulin resistance is due to so-called ectopic fat accumulation, the buildup of fat in places it's not supposed to be, like within our muscle cells. But not all fats affect the muscles the same. The type of fat, saturated vs. unsaturated, is critical. Saturated fats like palmitate, found mostly in meat, dairy and eggs, cause insulin resistance, but oleate, found mostly in nuts, olives and avocados may actually improve insulin sensitivity.

What makes saturated fat bad? Saturated fat causes more toxic breakdown products and mitochondrial dysfunction, and increases oxidative stress, free radicals and inflammation, establishing a vicious cycle of events in which saturated fat induces free radicals, causes dysfunction in the little power plants within our muscle cells (mitochondria), which then causes an increase in free radical production and an impairment of insulin signaling. I explain this in my video Lipotoxicity: How Saturated Fat Raises Blood Sugar.

Fat cells filled with saturated fat activate an inflammatory response to a far greater extent. This increased inflammation from saturated fat has been demonstrated to raise insulin resistance through free radical production. Saturated fat also has been shown to have a direct effect on skeletal muscle insulin resistance. Accumulation of saturated fat increases the amount of diacyl-glycerol in the muscles, which has been demonstrated to have a potent effect on muscle insulin resistance. You can take muscle biopsies from people and correlate the saturated fat buildup in their muscles with insulin resistance.

While monounsaturated fats are more likely to be detoxified or safely stored away, saturated fats create those toxic breakdown products like ceramide that causes lipotoxicity. Lipo- meaning fat, as in liposuction. This fat toxicity in our muscles is a well-known concept in the explanation of trigger for insulin resistance.

I've talked about the role saturated and trans fats contribute to the progression of other diseases, like autoimmune diseases, cancer and heart disease, but they can also cause insulin resistance, the underlying cause of prediabetes and type 2 diabetes. In the human diet, saturated fats are derived from animal sources while trans fats originate in meat and milk in addition to partially hydrogenated and refined vegetable oils.

That's why experimentally shifting people from animal fats to plant fats can improve insulin sensitivity. In a study done by Swedish researchers, insulin sensitivity was impaired on the diet with added butterfat, but not on the diet with added olive fat.

We know prolonged exposure of our muscles to high levels of fat leads to severe insulin resistance, with saturated fats demonstrated to be the worst, but they don't just lead to inhibition of insulin signaling, the activation of inflammatory pathways and the increase in free radicals, they also cause an alteration in gene expression. This can lead to a suppression of key mitochondrial enzymes like carnitine palmitoyltransferase, which finally solves the mystery of why those eating vegetarian have a 60 percent higher expression of that fat burning enzyme. They're eating less saturated fat.

So do those eating plant-based diets have less fat clogging their muscles and less insulin resistance too? There hasn't been any data available regarding the insulin sensitivity or inside muscle cell fat of those eating vegan or vegetarian... until now. Researchers at the Imperial College of London compared the insulin resistance and muscle fat of vegans versus omnivores. Those eating plant-based diets have the unfair advantage of being much slimmer, so they found omnivores who were as skinny as vegans to see if plant-based diets had a direct benefit, as opposed to indirectly pulling fat out of the muscles by helping people lose weight in general.

They found significantly less fat trapped in the muscle cells of vegans compared to omnivores at the same body weight, better insulin sensitivity, better blood sugar levels, better insulin levels and, excitingly, significantly improved beta-cell function (the cells in the pancreas that make the insulin). They conclude that eating plant-based is not only expected to be cardioprotective, helping prevent our #1 killer, heart disease, but that plant-based diets are beta-cell protective as well, helping also to prevent our seventh leading cause of death, diabetes.

This is the third of a three-part series, starting with What Causes Insulin Resistance? and The Spillover Effect Links Obesity to Diabetes.

Even if saturated fat weren't associated with heart disease, its effects on pancreatic function and insulin resistance in the muscles would be enough to warrant avoiding it. Despite popular press accounts, saturated fat intake remains the primary modifiable determinant of LDL cholesterol, the #1 risk factor for our #1 killer-heart disease. See The Saturated Fat Studies: Buttering Up the Public and The Saturated Fat Studies: Set Up to Fail.

How low should we shoot for in terms of saturated fat intake? As low as possible, according to the U.S. National Academies of Science Institute of Medicine: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

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: Andrew Malone / Flickr

Original Link

Lipotoxicity: How Saturated Fat Raises Blood Sugar

NF-Nov24 Lipotoxicity How Saturated Fat Raises Blood Sugar copy.jpg

The reason those eating plant-based diets have less fat buildup in their muscle cells and less insulin resistance may be because saturated fats appear to impair blood sugar control the most.

The association between fat and insulin resistance is now widely accepted. Insulin resistance is due to so-called ectopic fat accumulation, the buildup of fat in places it's not supposed to be, like within our muscle cells. But not all fats affect the muscles the same. The type of fat, saturated vs. unsaturated, is critical. Saturated fats like palmitate, found mostly in meat, dairy and eggs, cause insulin resistance, but oleate, found mostly in nuts, olives and avocados may actually improve insulin sensitivity.

What makes saturated fat bad? Saturated fat causes more toxic breakdown products and mitochondrial dysfunction, and increases oxidative stress, free radicals and inflammation, establishing a vicious cycle of events in which saturated fat induces free radicals, causes dysfunction in the little power plants within our muscle cells (mitochondria), which then causes an increase in free radical production and an impairment of insulin signaling. I explain this in my video Lipotoxicity: How Saturated Fat Raises Blood Sugar.

Fat cells filled with saturated fat activate an inflammatory response to a far greater extent. This increased inflammation from saturated fat has been demonstrated to raise insulin resistance through free radical production. Saturated fat also has been shown to have a direct effect on skeletal muscle insulin resistance. Accumulation of saturated fat increases the amount of diacyl-glycerol in the muscles, which has been demonstrated to have a potent effect on muscle insulin resistance. You can take muscle biopsies from people and correlate the saturated fat buildup in their muscles with insulin resistance.

While monounsaturated fats are more likely to be detoxified or safely stored away, saturated fats create those toxic breakdown products like ceramide that causes lipotoxicity. Lipo- meaning fat, as in liposuction. This fat toxicity in our muscles is a well-known concept in the explanation of trigger for insulin resistance.

I've talked about the role saturated and trans fats contribute to the progression of other diseases, like autoimmune diseases, cancer and heart disease, but they can also cause insulin resistance, the underlying cause of prediabetes and type 2 diabetes. In the human diet, saturated fats are derived from animal sources while trans fats originate in meat and milk in addition to partially hydrogenated and refined vegetable oils.

That's why experimentally shifting people from animal fats to plant fats can improve insulin sensitivity. In a study done by Swedish researchers, insulin sensitivity was impaired on the diet with added butterfat, but not on the diet with added olive fat.

We know prolonged exposure of our muscles to high levels of fat leads to severe insulin resistance, with saturated fats demonstrated to be the worst, but they don't just lead to inhibition of insulin signaling, the activation of inflammatory pathways and the increase in free radicals, they also cause an alteration in gene expression. This can lead to a suppression of key mitochondrial enzymes like carnitine palmitoyltransferase, which finally solves the mystery of why those eating vegetarian have a 60 percent higher expression of that fat burning enzyme. They're eating less saturated fat.

So do those eating plant-based diets have less fat clogging their muscles and less insulin resistance too? There hasn't been any data available regarding the insulin sensitivity or inside muscle cell fat of those eating vegan or vegetarian... until now. Researchers at the Imperial College of London compared the insulin resistance and muscle fat of vegans versus omnivores. Those eating plant-based diets have the unfair advantage of being much slimmer, so they found omnivores who were as skinny as vegans to see if plant-based diets had a direct benefit, as opposed to indirectly pulling fat out of the muscles by helping people lose weight in general.

They found significantly less fat trapped in the muscle cells of vegans compared to omnivores at the same body weight, better insulin sensitivity, better blood sugar levels, better insulin levels and, excitingly, significantly improved beta-cell function (the cells in the pancreas that make the insulin). They conclude that eating plant-based is not only expected to be cardioprotective, helping prevent our #1 killer, heart disease, but that plant-based diets are beta-cell protective as well, helping also to prevent our seventh leading cause of death, diabetes.

This is the third of a three-part series, starting with What Causes Insulin Resistance? and The Spillover Effect Links Obesity to Diabetes.

Even if saturated fat weren't associated with heart disease, its effects on pancreatic function and insulin resistance in the muscles would be enough to warrant avoiding it. Despite popular press accounts, saturated fat intake remains the primary modifiable determinant of LDL cholesterol, the #1 risk factor for our #1 killer-heart disease. See The Saturated Fat Studies: Buttering Up the Public and The Saturated Fat Studies: Set Up to Fail.

How low should we shoot for in terms of saturated fat intake? As low as possible, according to the U.S. National Academies of Science Institute of Medicine: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

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: Andrew Malone / Flickr

Original Link