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

How to Design Saturated Fat Studies to Hide the Truth

NF-Oct4 Saturated Fat Studies Set up to Fail.jpeg

Where do the international consensus guidelines to dramatically lower saturated fat consumption come from? (I show the list in my video, The Saturated Fat Studies: Buttering Up the Public). They came from literally hundreds of metabolic ward experiments, which means you don't just ask people to change their diets, you essentially lock them in a room--for weeks if necessary--and have total control over their diet. You can then experimentally change the level of saturated fat consumed by subjects however you want to, and see the corresponding change in their cholesterol levels. And the results are so consistent that you can create an equation, the famous Hegsted Equation, where you can predict how much their cholesterol will go up based on how much saturated fat you give them. So if you want your LDL cholesterol to go up 50 points, all you have to do is eat something like 30% of your calories in saturated fat. When you plug the numbers in, the change in cholesterol shoots up as predicted. The experiments match the predictions. You can do it at home with one of those home cholesterol testing kits, eat a stick of butter every day, and watch your cholesterol climb.

These ward experiments were done in 1965; meaning we've known for 50 years that even if you keep calorie intake the same, increases in saturated fat intake are associated with highly significant increases in LDL bad cholesterol. Your good cholesterol goes up a bit too, but that increase is smaller than the increase in bad, which would translate into increased heart disease risk.

So if you feed vegetarians meat even just once a day, their cholesterol jumps nearly 20% within a month. To prevent heart disease, we need a total cholesterol under 150, which these vegetarians were, but then even just eating meat once a day, and their cholesterol shot up 19%. The good news is that within just two weeks of returning to their meat-free diet, their cholesterol dropped back down into the safe range. Note that their HDL good cholesterol hardly moved at all, so their ratio went from low risk of heart attack to high risk in a matter of weeks with just one meat-containing meal a day. And indeed randomized clinical trials show that dietary saturated fat reduction doesn't just appear to reduce cholesterol levels, but also reduces the risk of subsequent cardiovascular events like heart attacks.

So we have randomized clinical trials, controlled interventional experiments--our most robust forms of evidence--no wonder there's a scientific consensus to decrease saturated fat intake! You'll note, though, that the Y-axis in these studies seen in my video The Saturated Fat Studies: Set Up to Fail is not cholesterol, but change in cholesterol. That's because everyone's set-point is different. Two people eating the same diet with the same amount of saturated fat can have very different cholesterol levels. One person can eat ten chicken nuggets a day and have an LDL cholesterol of 90; another person eating ten a day could start out with an LDL of 120. It depends on your genes. But while our genetics may be different, our biology is the same, meaning the rise and drop in cholesterol is the same for everyone. So if both folks cut out the nuggets, the 90 might drop to 85, whereas the 120 would drop to 115. Wherever we start, we can lower our cholesterol by eating less saturated fat, but if I just know your saturated fat intake--how many nuggets you eat, I can't tell you what your starting cholesterol is. All I can say with certainty is that if you eat less, your cholesterol will likely improve.

But because of this extreme "interindividual variation"--this wide variability in baseline cholesterol levels for any given saturated fat intake--if you take a cross-section of the population, you can find no statistical correlation between saturated fat intake and cholesterol levels, because it's not like everyone who eats a certain set amount of saturated fat is going to have over a certain cholesterol. So there are three ways you could study diet and cholesterol levels: controlled feeding experiments, free-living dietary change experiments, or cross-sectional observations of large populations. As we know, there is a clear and strong relationship between change in diet and change in serum cholesterol in the interventional designs, but because of that individual variability, in cross-sectional designs, you can get zero correlation. In fact, if you do the math, that's what you'd expect you'd get. In statistical parlance, one would say that a cross-sectional study doesn't have the power for detecting such a relationship. Thus because of that variability, these kinds of observational studies would seem an inappropriate method to study this particular relationship. So since diet and serum cholesterol have a zero correlation cross-sectionally, an observational study of the relationship between diet and coronary heart disease incidence will suffer from the same difficulties. So again, if you do the math, observational studies would unavoidably show nearly no correlation between saturated fat and heart disease. These prospective studies can be valuable for other diseases, but the appropriate design demonstrating or refuting the role of diet and coronary heart disease is a dietary change experiment.

And those dietary change experiments have been done; they implicate saturated fat, hence the lower saturated guidelines from basically every major medical authority. In fact, if we lower saturated fat enough, we may be able to reverse heart disease, opening up arteries without drugs or surgery. So with this knowledge, how would the meat and dairy industry prove otherwise? They use the observational studies that mathematically would be unable to show any correlation.

All they need now is a friendly researcher, such as Ronald M. Krauss, who has been funded by the National Dairy Council since 1989, also the National Cattleman's Beef Association, as well as the Atkins Foundation. Then they just combine all the observational studies that don't have the power to provide significant evidence, and not surprisingly, as published in their 2010 meta-analysis, no significant evidence was found.

The 2010 meta-analysis was basically just repackaged for 2014, using the same and similar studies. As the Chair of Harvard's nutrition department put it, their conclusions regarding the type of fat being unimportant are seriously misleading and should be disregarded, going as far as suggesting the paper be retracted, even after the authors corrected a half dozen different errors.

It's not as though they falsified or fabricated data--they didn't have to. They knew beforehand the limitations of observational studies, they knew they'd get the "right" result and so they published it, helping to "neutralize the negative impact of milk and meat fat by regulators and medical professionals." And it's working, according to the dairy industry, as perceptions about saturated fat in the scientific community are changing. They even go so far to say this is a welcome message to consumers, who may be tired of hearing what they shouldn't eat. They don't need to convince consumers, just confuse them. Confusion can easily be misused by the food industry to promote their interests.

It's like that infamous tobacco industry memo that read, "Doubt is our product since it's the best means of competing with the body of fact that exist in the mind of the general public." They don't have to convince the public that smoking is healthy to get people to keep consuming their products. They just need to establish a controversy. Conflicting messages in nutrition cause people to become so frustrated and confused they may just throw their hands up in the air and eat whatever is put in front of them, which is exactly what saturated fat suppliers want, but at what cost to the public's health?


If that "Doubt is our product" memo sounded familiar, I also featured it in my Food Industry Funded Research Bias video. More on how industries can design deceptive studies in BOLD Indeed: Beef Lowers Cholesterol? and How the Egg Board Designs Misleading Studies.

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Taryn / Flickr

Original Link

How to Mitigate and Prevent Crohn’s Disease with Diet

NF-Sept20 Preventing Crohn's Disease With Diet.jpeg

Crohn's disease is an autoimmune disorder that affects more than a million Americans. It is an inflammatory bowel disease in which the body attacks the intestines. There is currently no known cure for Crohn's disease; current research focuses on controlling symptoms. There is no definitive medical or surgical therapy. The best we have is a plant-based diet, which has afforded the best relapse prevention to date.

Researchers got the idea to try a plant-based diet because diets rich in animal protein and animal fat have been found to cause a decrease in beneficial bacteria in the intestine. So, researchers designed a semi-vegetarian diet to counter that, and 100 percent of subjects stayed in remission the first year and 92 percent the second year. These results are far better than those obtained by current drugs, including new "biological agents" that can cost $40,000 a year, and can cause progressive multifocal leukoencephalopathy, a disabling and deadly brain disease. And a healthy diet appears to work better.

But what about preventing Crohn's disease in the first place? A systematic review of the scientific literature on dietary intake and the risk of developing inflammatory bowel disease found that a high intake of fats and meat was associated with an increased risk of Crohn's disease as well as ulcerative colitis, whereas high fiber and fruit intakes were associated with decreased risk of Crohn's.

These results were supported more recently by the Harvard Nurse's Health Study. Data revealed that long-term intake of dietary fiber, particularly from fruit, was associated with lower risk of Crohn's disease. Women who fell into in the highest long-term fiber consumption group had a 40 percent reduced risk, leading the accompanying editorial to conclude, "advocating for a high-fiber diet may ultimately reduce the incidence of Crohn's disease."

The irony is that the highest fiber group wasn't even eating the official recommended daily minimum of fiber intake. Apparently, even just being less fiber deficient has a wide range of benefits, including a significant reduction in the risk of developing Crohn's disease, but why? The authors suggest it's because "fiber plays a vital role in the maintenance of our intestinal barrier function."

Our skin keeps the outside world outside, and so does the lining of our gut, but in Crohn's disease, this barrier function is impaired. You can see this under an electron microscope as shown in my video Preventing Crohn's Disease With Diet. The tight junctions between the intestinal cells have all sorts of little holes and breaks. The thought is that the increase in prevalence of inflammatory bowel diseases may be that dietary changes lead to the breakdown of our intestinal barrier, potentially allowing the penetration of bacteria into our gut wall, which our body then attacks, triggering the inflammation.

We know fiber acts as a prebiotic in our colon (large intestine), feeding our good bacteria, but what does fiber do in our small intestine where Crohn's often starts? We didn't know, until a landmark study was published. Researchers wanted to find out what could stop Crohn's associated invasive bacteria from tunneling into the gut wall. They found the invasion is inhibited by the presence of certain soluble plant fibers, such as from plantains and broccoli at the kinds of concentrations one might expect after eating them. They wondered if that may explain why plantain-loving populations have lower levels of inflammatory bowel disease. But, the researchers also found that there was something in processed foods that facilitated the invasion of the bacteria. Polysorbate 80 was one of them, found predominantly in ice cream, but also found in Crisco, Cool Whip, condiments, cottage cheese--you just have to read the labels.

What about maltodextrin, which is found in artificial sweeteners like Splenda, snack foods, salad dressings, and fiber supplements? Maltodextrin markedly enhanced the ability of the bacteria to glob onto our intestinal cells, though other additives. Carboxy-methyl cellulose and xanthan gum appeared to have no adverse effects.

This may all help solve the mystery of the increasing prevalence of Crohn's disease in developed nations, where we're eating less fiber-containing whole plant foods and more processed foods. What we need now are interventional studies to see if boosting fiber intake and avoiding these food additives can be effective in preventing and treating Crohn's disease. But until then, what do we tell people? The available evidence points to a diet low in animal fat, with lots of soluble fiber containing plant foods, and avoiding processed fatty foods that contain these emulsifiers. We also want to make sure we're not ingesting traces of dishwashing detergent, which could have the same effect, so make sure to rinse your dishes well. Researchers found that some people wash dishes and then just leave them to dry without rinsing, which is probably not a good idea. We don't currently have studies that show that avoiding polysorbate 80 and rinsing dishes well actually helps. Nevertheless, advice based on 'best available evidence' is better than no advice at all.

Here's a video about using a more plant-based diet to reduce the risk of relapses: Dietary Treatment of Crohn's Disease.

I get a lot of questions about additives like polysorbate 80. I'm glad I was finally able to do a blog about it. Here are some videos on some others:

If you, like me, used to think all fiber was good for was helping with bowel regularity you'll be amazed! See for example, Dr. Burkitt's F-Word 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--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Graphic Stock

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Side-Effects of Aspartame on the Brain

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The National Institutes of Health AARP study of hundreds of thousands of Americans followed for years found that frequent consumption of sweetened beverages, especially diet drinks, may increase depression risk among older adults. Whether soda, fruit-flavored drinks, or iced tea, those artificially sweetened drinks appeared to carry higher risk. There was a benefit in coffee drinkers compared to non-drinkers, but if they added sugar, much of the benefits appeared to disappear, and if they added Equal or Sweet-and-Low, the risk appeared to go up.

Various effects of artificial sweeteners, including neurological effects, have been suspected. For example, aspartame--the chemical in Equal and Nutrasweet--may modulate brain neurotransmitters such as dopamine and serotonin, although data have been controversial and inconsistent. Scientific opinions range from "safe under all conditions" to "unsafe at any dose." The controversy started in the 80's soon after aspartame was approved. Researchers at the Mass College of Pharmacy and MIT noted:

"given the very large number of Americans routinely exposed, if only 1% of the 100,000,000 Americans thought to consume aspartame ever exceed the sweetener's acceptable daily intake, and if only 1% of this group happen coincidentally to have an underlying disease that makes their brains vulnerable to the effects, then the number of people who might manifest adverse brain reactions attributable to aspartame could still be about 10,000, a number on the same order as the number of brain and nerve-related consumer complaints already registered with the FDA before they stopped accepting further reports on adverse reactions to the sweetener."

Those with a history of depression might be especially vulnerable. Researchers at Case Western designed a study I highlighted in my video Aspartame and the Brain to ascertain whether individuals with mood disorders are particularly vulnerable to adverse effects of aspartame. Although they had planned on recruiting 40 patients with depression and 40 controls, the project was halted early by the Institutional Review Board for safety reasons because of the severity of reactions to aspartame within the group of patients with a history of depression.

It was decided that it was unethical to continue to expose people to the stuff.

Normally when we study a drug or a food, the company donates the product to the researchers because they're proud of the benefits or safety of their product. But the Nutrasweet company refused to even sell it to these researchers. The researchers managed to get their hands on some, and within a week there were significantly more adverse effects reported in the aspartame group than in the placebo group. They concluded that individuals with mood disorders may be particularly sensitive to aspartame, and therefore its use in this population should be discouraged.

In a review of the direct and indirect cellular effects of aspartame on the brain, it was noted that there are reports of aspartame causing neurological and behavioral disturbances in sensitive individuals, such as headaches, insomnia and seizures. The researchers go even further and propose that excessive aspartame ingestion might be involved in the development of certain mental disorders and also in compromised learning and emotional functioning. They conclude that "due to all the adverse effects caused by aspartame, it is suggested that serious further testing and research be undertaken to eliminate any and all controversies," to which someone responded in the journal that "there really is no controversy," arguing that aspartame was conclusively toxic.

But what do they mean by excessive ingestion? The latest study on the neuro-behavioral effects of aspartame consumption put people on a high aspartame diet compared to a low aspartame diet. But even the high dose at 25 mg/kg was only half the adequate daily intake set by the FDA. The FDA says one can safely consume 50mg a day, but after just eight days on half of that, participants had more irritable mood, exhibited more depression, and performed worse on certain brain function tests. And these weren't people with a pre-existing history of mental illness; these were just regular people. The researchers concluded that "given that the higher intake level tested here was well below the maximum acceptable daily intake level [40mg in Europe, 50mg here] careful consideration is warranted when consuming food products that may affect neurobehavioral health."

Easier said than done, since it's found in more than 6,000 foods, apparently making artificial sweeteners "impossible to completely eradicate from daily exposure." While that may be true for the great majority of Americans, it's only because they elect to eat processed foods. If we stick to whole foods, we don't even have to read the ingredients lists, because the healthiest foods in the supermarket are label-free, they don't even have ingredients lists--produce!

I've previously touched on artificial sweeteners before:

The healthiest caloric sweeteners are blackstrap molasses and date sugar (whole dried powdered dates). The least toxic low-calorie sweetener is probably erythritol (Erythritol May Be a Sweet Antioxidant).

Coffee may decrease suicide and cancer risk (Preventing Liver Cancer with Coffee? and Coffee and Cancer) but may impair blood flow to the heart (Coffee and Artery Function).

Other ways to improve mood include:

In health,
Michael Greger, M.D.

PS: If you haven't yet, you can subscribe to my free videos here and watch my live, year-in-review presentations--2013: Uprooting the Leading Causes of Death, More Than an Apple a Day, 2014: From Table to Able: Combating Disabling Diseases with Food, 2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet, and my latest, 2016: How Not To Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers.

Image Credit: Mike Mozart / Flickr

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Exercise as Medicine

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Physical inactivity has been called the biggest public health problem of the 21st century. Of course just because someone calls it that doesn't mean it's true, in fact physical inactivity ranks down at #5 in terms of risk factors for death, and #6 in terms of risk factors for disability. Diet is by far our greatest killer, followed by smoking.

But, there is irrefutable evidence of the "effectiveness of regular physical activity in the prevention of several chronic diseases--cardiovascular disease, diabetes, cancer, hypertension, obesity, depression, osteoporosis, and premature death"--helping to add years to our life, and above all, "life to our years." It truly may be survival of the fittest.

How much exercise do we need? In general, the answer is the more the better. Currently, "most health and fitness organizations advocate a minimum of a thousand calories of exercise a week," which is equivalent to walking an hour a day five days a week. Seven days a week, though, may be even better in terms of extending one's lifespan.

Exercise is so important that not walking an hour a day is considered a high risk behavior, alongside smoking, excess drinking, and being obese. Having any one of these effectively ages us three to five years in terms of risk of dying prematurely, though interestingly those who ate green vegetables on a daily basis did not appear to have that same bump in risk. Even if broccoli-eating couch potatoes live as long as walkers, there are a multitude of ancillary health benefits to physical activity that doctors are encouraged to prescribe it, to signal to the patient that "exercise is medicine."

Researchers at the London School, Harvard, and Stanford compared exercise to drug interventions in study highlighted in my video, Longer Life Within Walking Distance, and found that exercise often worked just as well as drugs for the treatment of heart disease, stroke, and diabetes. There's not a lot of money to fund exercise studies, so one option would be to require drug companies to compare any new drug to exercise. In cases where drug options provide only modest benefit, patients deserve to understand the relative impact that physical activity might have on their condition.

Exercise is just one of four lifestyle behaviors found to significantly extend our lifespan. See my video, Turning the Clock Back 14 Years.

Other longevity videos include:

More videos on exercise:

What about the stress it can put on our bodies? 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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: Dominic Alves / Flickr

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