How Exactly Does Type 2 Diabetes Develop?

How Exactly Does Type 2 Diabetes Develop.jpeg

Insulin resistance is the cause of both prediabetes and type 2 diabetes. OkK, so what is the cause of insulin resistance? Insulin resistance is now accepted to be closely associated with the accumulation of fat within our muscle cells. This fat toxicity inside of our muscles is a major factor in the cause of insulin resistance and type 2 diabetes, as it interferes with the action of insulin. I've explored how fat makes our muscles insulin resistant (see What Causes Insulin Resistance?), how that fat can come from the fat we eat or the fat we wear (see The Spillover Effect Links Obesity to Diabetes), and how not all fats are the same (see Lipotoxicity: How Saturated Fat Raises Blood Sugar). It's the type of fat found predominantly in animal fats, relative to plant fats, that appears to be especially deleterious with respect to fat-induced insulin insensitivity. But this insulin resistance in our muscles starts years before diabetes is diagnosed.

In my video, Diabetes as a Disease of Fat Toxicity, you can see that insulin resistance starts over a decade before diabetes is actually diagnosed, as blood sugar levels slowly start creeping up. And then, all of the sudden, the pancreas conks out, and blood sugars skyrocket. What could underlie this relatively rapid failure of insulin secretion?

At first, the pancreas pumps out more and more insulin, trying to overcome the fat-induced insulin resistance in the muscles, and high insulin levels can lead to the accumulation of fat in the liver, called fatty liver disease. Before diagnosis of type 2 diabetes, there is a long silent scream from the liver. As fat builds up in our liver, it also becomes resistant to insulin.

Normally, the liver is constantly producing blood sugar to keep our brain alive between meals. As soon as we eat breakfast, though, the insulin released to deal with the meal normally turns off liver glucose production, which makes sense since we don't need it anymore. But when our liver is filled with fat, it becomes insulin resistant like our muscles, and doesn't respond to the breakfast signal; it keeps pumping out blood sugar all day long on top of whatever we eat. Then the pancreas pumps out even more insulin to deal with the high sugars, and our liver gets fatter and fatter. That's one of the twin vicious cycles of diabetes. Fatty muscles, in the context of too many calories, leads to a fatty liver, which leads to an even fattier liver. This is all still before we have diabetes.

Fatty liver can be deadly. The liver starts trying to offload the fat by dumping it back into the bloodstream in the form of something called VLDL, and that starts building up in the cells in the pancreas that produce the insulin in the first place. Now we know how diabetes develops: fatty muscles lead to a fatty liver, which leads to a fatty pancreas. It is now clear that type 2 diabetes is a condition of excess fat inside our organs, whether we're obese or not.

The only thing that was keeping us from diabetes-unchecked skyrocketing blood sugars-is that the pancreas was working overtime pumping out extra insulin to overcome insulin resistance. But as the so-called islet or Beta cells in the pancreas are killed off by the fatty buildup, insulin production starts to fail, and we're left with the worst of both worlds: insulin resistance combined with a failing pancreas. Unable to then overcome the resistance, blood sugar levels go up and up, and boom: type 2 diabetes.

This has implications for cancer as well. Obesity leads to insulin resistance and our blood sugars start to go up, so our pancreas starts pumping out more insulin to try to force more sugar into our muscles, and eventually the fat spills over into the pancreas, killing off the insulin-producing cells. Then we develop diabetes, in which case we may have to start injecting insulin at high levels to overcome the insulin-resistance, and these high insulin levels promote cancer. That's one of the reasons we think obese women get more breast cancer. It all traces back to fat getting into our muscle cells, causing insulin resistance: fat from our stomach (obesity) or fat going into our stomach (saturated fats in our diet).

Now it should make sense why the American Diabetes Association recommends reduced intake of dietary fat as a strategy for reducing the risk for developing diabetes.


The reason I'm going into all this detail is that I'm hoping to empower both those suffering from the disease and those treating sufferers so as to better understand dietary interventions to prevent and treat the epidemic.

Here are some videos on prevention:

And here are some on treatment:

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: Nephron. This image has been modified.

Original Link

How Exactly Does Type 2 Diabetes Develop?

How Exactly Does Type 2 Diabetes Develop.jpeg

Insulin resistance is the cause of both prediabetes and type 2 diabetes. OkK, so what is the cause of insulin resistance? Insulin resistance is now accepted to be closely associated with the accumulation of fat within our muscle cells. This fat toxicity inside of our muscles is a major factor in the cause of insulin resistance and type 2 diabetes, as it interferes with the action of insulin. I've explored how fat makes our muscles insulin resistant (see What Causes Insulin Resistance?), how that fat can come from the fat we eat or the fat we wear (see The Spillover Effect Links Obesity to Diabetes), and how not all fats are the same (see Lipotoxicity: How Saturated Fat Raises Blood Sugar). It's the type of fat found predominantly in animal fats, relative to plant fats, that appears to be especially deleterious with respect to fat-induced insulin insensitivity. But this insulin resistance in our muscles starts years before diabetes is diagnosed.

In my video, Diabetes as a Disease of Fat Toxicity, you can see that insulin resistance starts over a decade before diabetes is actually diagnosed, as blood sugar levels slowly start creeping up. And then, all of the sudden, the pancreas conks out, and blood sugars skyrocket. What could underlie this relatively rapid failure of insulin secretion?

At first, the pancreas pumps out more and more insulin, trying to overcome the fat-induced insulin resistance in the muscles, and high insulin levels can lead to the accumulation of fat in the liver, called fatty liver disease. Before diagnosis of type 2 diabetes, there is a long silent scream from the liver. As fat builds up in our liver, it also becomes resistant to insulin.

Normally, the liver is constantly producing blood sugar to keep our brain alive between meals. As soon as we eat breakfast, though, the insulin released to deal with the meal normally turns off liver glucose production, which makes sense since we don't need it anymore. But when our liver is filled with fat, it becomes insulin resistant like our muscles, and doesn't respond to the breakfast signal; it keeps pumping out blood sugar all day long on top of whatever we eat. Then the pancreas pumps out even more insulin to deal with the high sugars, and our liver gets fatter and fatter. That's one of the twin vicious cycles of diabetes. Fatty muscles, in the context of too many calories, leads to a fatty liver, which leads to an even fattier liver. This is all still before we have diabetes.

Fatty liver can be deadly. The liver starts trying to offload the fat by dumping it back into the bloodstream in the form of something called VLDL, and that starts building up in the cells in the pancreas that produce the insulin in the first place. Now we know how diabetes develops: fatty muscles lead to a fatty liver, which leads to a fatty pancreas. It is now clear that type 2 diabetes is a condition of excess fat inside our organs, whether we're obese or not.

The only thing that was keeping us from diabetes-unchecked skyrocketing blood sugars-is that the pancreas was working overtime pumping out extra insulin to overcome insulin resistance. But as the so-called islet or Beta cells in the pancreas are killed off by the fatty buildup, insulin production starts to fail, and we're left with the worst of both worlds: insulin resistance combined with a failing pancreas. Unable to then overcome the resistance, blood sugar levels go up and up, and boom: type 2 diabetes.

This has implications for cancer as well. Obesity leads to insulin resistance and our blood sugars start to go up, so our pancreas starts pumping out more insulin to try to force more sugar into our muscles, and eventually the fat spills over into the pancreas, killing off the insulin-producing cells. Then we develop diabetes, in which case we may have to start injecting insulin at high levels to overcome the insulin-resistance, and these high insulin levels promote cancer. That's one of the reasons we think obese women get more breast cancer. It all traces back to fat getting into our muscle cells, causing insulin resistance: fat from our stomach (obesity) or fat going into our stomach (saturated fats in our diet).

Now it should make sense why the American Diabetes Association recommends reduced intake of dietary fat as a strategy for reducing the risk for developing diabetes.


The reason I'm going into all this detail is that I'm hoping to empower both those suffering from the disease and those treating sufferers so as to better understand dietary interventions to prevent and treat the epidemic.

Here are some videos on prevention:

And here are some on treatment:

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: Nephron. This image has been modified.

Original Link

Four Ways to Improve on the Mediterranean Diet

Improving on the Mediterranean Diet.jpg

The traditional Mediterranean diet can be considered mainly, but not exclusively, as a plant-based diet, and certainly not a whole foods, plant-based diet. Olive oil and wine can be considered essentially fruit juices. Even if one is eating a "vegiterranean diet," an entirely plant-based version, there are a number of problematic nutritional aspects that are rarely talked about. For example, the Mediterranean diet includes lots of white bread, white pasta and not a lot of whole grains.

In an anatomy of the health effects of the Mediterranean diet, the single most important component was the high consumption of plant foods. In contrast, high cereal consumption, meaning high grain consumption, did not appear to help. This may be because most grains that modern Mediterranean dieters eat are refined, like white bread, whereas the traditional Mediterranean diet was characterized by unprocessed cereals--in other words, whole grains. And while whole grains have been associated with lower risk of diabetes, heart disease and cancer, refined grain may increase the risk of diabetes, obesity, heart disease and other chronic diseases. In the PREDIMED study, those who ate the most white bread--but not whole grain bread--gained significant weight.

Alcohol may also be a problem. As a plant-centered diet, adherence to a Mediterranean diet is associated with lower cancer risk, but does not appear to lower breast cancer risk. With all the fruits, veggies, nuts, seeds, beans and low saturated fat content, you'd assume there would be lower breast cancer risk, but alcohol is a known breast carcinogen, even in moderate amounts. When researchers created a special adapted version of the Mediterranean diet score that excluded alcohol, the diet does indeed appear to reduce breast cancer risk.

The wonderful grape phytonutrients in red wine can improve our arterial function such that if you drink nonalcoholic red wine (wine with the alcohol removed), you get a significant boost in endothelial function--the ability of our arteries to relax and dilate normally, increasing blood flow. If you drink the same red wine with alcohol, it abolishes the beneficial effect and counteracts the benefit of the grape phytonutrients. So, it would be better just to eat grapes. You can find more information about this in my video Improving on the Mediterranean Diet.

Similarly, there are components of extra virgin olive oil--the antioxidant phytonutrients, that may help endothelial function, but when consumed as oil, (even extra virgin olive oil), it may impair arterial function. So even if white bread dipped in olive oil is the very symbol of the Mediterranean diet, we can modernize it by removing oils and refined grains.

Another important, albeit frequently ignored issue in the modern Mediterranean diet is sodium intake. Despite evidence linking salt intake to high blood pressure, heart disease and strokes, dietary salt intake in the U.S. is on the rise. Right now, Americans get about seven to ten grams a day, mostly from processed foods. If we were to decrease that just by three grams every year, we could possibly save tens of thousands of people from having a heart attack, prevent tens of thousands of strokes, and tens of thousands of deaths. There is a common misperception that only certain people should reduce their salt intake and that for the vast majority of the population, salt reduction is unnecessary, but in reality, the opposite is true.

There is much we can learn from the traditional Mediterranean diet. A defining characteristic of the Mediterranean diet is an abundance of plant foods, but one thing that seems to have fallen by the wayside. No main Mediterranean meal is replete without lots of greens, a key part of not only a good Mediterranean diet, but of any good diet.

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

I touch more on whole grains in How Many Meet the Simple Seven? and Whole Grains May Work As Well As Drugs.

More on breast cancer and alcohol in Breast Cancer and Alcohol: How Much Is Safe?, Preventing Skin Cancer From the Inside Out, and Breast Cancer Risk: Red Wine v. White Wine.

I've touched on olive oil in the other videos in this Mediterranean diet series, but also have an older video Extra Virgin Olive Oil vs. Nuts and more recently, Olive Oil & Artery Function.

More on sodium in Dietary Guidelines: With a Grain of Big Salt, Big Salt - Getting to the Meat of the Matter, and Can Diet Protect Against Kidney Cancer? But what if without salt everything tastes like cardboard? Not to worry! See Changing Our Taste Buds.

In health,

Michael Greger, M.D.

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

Image Credit: Sally Plank / Flickr. This image has been modified.

Original Link

Four Ways to Improve on the Mediterranean Diet

Improving on the Mediterranean Diet.jpg

The traditional Mediterranean diet can be considered mainly, but not exclusively, as a plant-based diet, and certainly not a whole foods, plant-based diet. Olive oil and wine can be considered essentially fruit juices. Even if one is eating a "vegiterranean diet," an entirely plant-based version, there are a number of problematic nutritional aspects that are rarely talked about. For example, the Mediterranean diet includes lots of white bread, white pasta and not a lot of whole grains.

In an anatomy of the health effects of the Mediterranean diet, the single most important component was the high consumption of plant foods. In contrast, high cereal consumption, meaning high grain consumption, did not appear to help. This may be because most grains that modern Mediterranean dieters eat are refined, like white bread, whereas the traditional Mediterranean diet was characterized by unprocessed cereals--in other words, whole grains. And while whole grains have been associated with lower risk of diabetes, heart disease and cancer, refined grain may increase the risk of diabetes, obesity, heart disease and other chronic diseases. In the PREDIMED study, those who ate the most white bread--but not whole grain bread--gained significant weight.

Alcohol may also be a problem. As a plant-centered diet, adherence to a Mediterranean diet is associated with lower cancer risk, but does not appear to lower breast cancer risk. With all the fruits, veggies, nuts, seeds, beans and low saturated fat content, you'd assume there would be lower breast cancer risk, but alcohol is a known breast carcinogen, even in moderate amounts. When researchers created a special adapted version of the Mediterranean diet score that excluded alcohol, the diet does indeed appear to reduce breast cancer risk.

The wonderful grape phytonutrients in red wine can improve our arterial function such that if you drink nonalcoholic red wine (wine with the alcohol removed), you get a significant boost in endothelial function--the ability of our arteries to relax and dilate normally, increasing blood flow. If you drink the same red wine with alcohol, it abolishes the beneficial effect and counteracts the benefit of the grape phytonutrients. So, it would be better just to eat grapes. You can find more information about this in my video Improving on the Mediterranean Diet.

Similarly, there are components of extra virgin olive oil--the antioxidant phytonutrients, that may help endothelial function, but when consumed as oil, (even extra virgin olive oil), it may impair arterial function. So even if white bread dipped in olive oil is the very symbol of the Mediterranean diet, we can modernize it by removing oils and refined grains.

Another important, albeit frequently ignored issue in the modern Mediterranean diet is sodium intake. Despite evidence linking salt intake to high blood pressure, heart disease and strokes, dietary salt intake in the U.S. is on the rise. Right now, Americans get about seven to ten grams a day, mostly from processed foods. If we were to decrease that just by three grams every year, we could possibly save tens of thousands of people from having a heart attack, prevent tens of thousands of strokes, and tens of thousands of deaths. There is a common misperception that only certain people should reduce their salt intake and that for the vast majority of the population, salt reduction is unnecessary, but in reality, the opposite is true.

There is much we can learn from the traditional Mediterranean diet. A defining characteristic of the Mediterranean diet is an abundance of plant foods, but one thing that seems to have fallen by the wayside. No main Mediterranean meal is replete without lots of greens, a key part of not only a good Mediterranean diet, but of any good diet.

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

I touch more on whole grains in How Many Meet the Simple Seven? and Whole Grains May Work As Well As Drugs.

More on breast cancer and alcohol in Breast Cancer and Alcohol: How Much Is Safe?, Preventing Skin Cancer From the Inside Out, and Breast Cancer Risk: Red Wine v. White Wine.

I've touched on olive oil in the other videos in this Mediterranean diet series, but also have an older video Extra Virgin Olive Oil vs. Nuts and more recently, Olive Oil & Artery Function.

More on sodium in Dietary Guidelines: With a Grain of Big Salt, Big Salt - Getting to the Meat of the Matter, and Can Diet Protect Against Kidney Cancer? But what if without salt everything tastes like cardboard? Not to worry! See Changing Our Taste Buds.

In health,

Michael Greger, M.D.

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

Image Credit: Sally Plank / Flickr. This image has been modified.

Original Link

How Well Do Cholesterol-Lowering Drugs Actually Work?

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One of the reasons people may undervalue diet and lifestyle changes is an overconfidence in the ability of pills and procedures to prevent disease. For example, people tend to wildly overestimate the power of things like mammograms and colonoscopies to prevent deaths from breast and bowel cancer, or the power of drugs like Fosamax to prevent hip fractures, or the power of cholesterol drugs to prevent fatal heart attacks. Patients believe statin drugs like Lipitor are about 100 times more effective than they actually are in preventing heart attacks. Studies show most people wouldn't take multiple blood pressure medications if they knew the truth.

For most people, the chance of benefit is normally less than 5 percent over five years for cholesterol, blood pressure, and blood thinning drugs. Patients don't want to take drugs unless they have at least a one in five chance--even those who just had a heart attack. It's no wonder, then, that doctors seldom share these figures. Informing patients of the percentage chance of benefit from preventive drug strategies would likely substantially reduce the likelihood that patients would agree to take the drugs every day for the rest of their lives.

For the individual, this is unlikely to be detrimental; after all, there's a 95 percent chance it won't do anything for them. But for the population at large, it would make a difference, so doctors and drug companies oversell the benefits by conveniently not mentioning how tiny they actually are, knowing most patients wouldn't take them if doctors divulged the truth. To practice non-lifestyle medicine is to practice deceptive medicine.

The best that cholesterol-lowering statin drugs appear to do is an absolute risk reduction of 3.1 percent over six years. If Dr. Esselstyn's work can be replicated in a randomized, controlled trial, then a whole foods plant-based diet will have been shown to work twenty times better, an absolute risk reduction of 60 percent after less than four years. In Esselstyn's study, 99.4 percent of high-risk patients that stuck with the diet avoided major cardiac events, such as death from heart attack.

When we have to decide whether we want to go diet versus drugs, we're not making a choice between eating healthy to prevent a heart attack or taking a pill to prevent a heart attack. Because in 97 percent of cases in the near-term, pills don't do anything. We're risking side effects for nothing, whereas if we treat the underlying root cause of the disease by eating a healthy, cholesterol-free diet, we may even reverse the progression of the disease, as seen in my video The Actual Benefit of Diet vs. Drugs.

If we stop eating an artery-clogging diet, our bodies can start dissolving that plaque away, opening up arteries in some cases without drugs or surgery. A healthy whole food plant-based diet by itself may work 20 times better than drugs to combat our #1 killer.

Now that's something doctors may want to tell their patients.

Yes, an ounce of prevention is worth a pound of cure, but a pound isn't that heavy--why change our diet and lifestyle when we can just wait and let modern medicine fix us up? Turns out we overestimate the efficacy of treatment as well, the subject of my video Why Prevention is Worth a Ton of Cure.

Sometimes preventive medicine procedures can even be harmful. See Cancer Risk From CT Scan Radiation and Do Dental X-Rays Cause Brain Tumors?

I've previously noted how an honest physician-patient interaction might go in Fully Consensual Heart Disease Treatment, Optimal Diet: Just Give it To Me Straight, Doc and Disclosing Conflicts of Interest in Medical Research. What should we be saying? See: What Diet Should Physician's Recommend?

So why don't more doctors do it? See Barriers to Heart Disease Prevention and Find Out If Your Doctor Takes Drug Company Money.

More on Dr. Esselstyn's heart disease reversal study in: Evidence-Based Medicine or Evidence-Biased?

Of course then there's just the brute force method: Kempner Rice Diet: Whipping Us Into Shape.

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: [akz] © 123RF.com

Original Link

Reversal of Chronic Disease Risk Even Late in Life

NF-Oct18 Never too Late to Start Eating Healthier.jpeg

A hundred years ago, the New York Times reported on a rather sophisticated study for the time: 4,600 cases of cancer appearing over a seven year period, suggesting that the increased consumption of animal foods was to blame. A century later, the latest review on the subjects concluded that mortality from all causes put together, ischemic heart disease, circulatory, and cerebrovascular diseases was significantly lower in those eating meat-free diets, in addition to less cancer and diabetes.

I'm surprised they found such significant results given that people in these studies typically didn't stop eating meat until late in life. For example, in the largest study done up until recently, up to a third of subjects ate vegetarian for less than five years, yet they still ended up with lower rates of heart disease whether they were under 60 or over 60, normal weight or overweight, used to smoke or never smoked; those that had stopped eating meat had lower risk, suggesting that decades of higher risk dietary behavior could be reversed within just years of eating healthier.

If you look at countries that switched from eating traditional, more plant-based diets to more Westernized diets, it may take 20 years for cancer rates to shoot up. It takes decades for most tumors to grow. For example, if you look at Asia, their dietary shift was accompanied by a remarkable increase in mortality rates of breast, colon, and prostate cancers. The same thing can be shown with migration studies. Men moving from rural China to the U.S. experience a dramatic increase in cancer risk, but tumors take time to grow.

So it's remarkable to me that after most of a lifetime eating the standard Western diet, one can turn it around and reverse chronic disease risk with a healthier diet, even late in the game... as discussed in my video, Never Too Late to Start Eating Healthier.

So, "should we all start eating vegetarian?" asked an editorial that accompanied the results from the largest study ever published on Americans eating plant-based diets, which found vegetarian diets to be associated with lower all-cause mortality, meaning those who started eating vegetarian live, on average, longer lives. This analysis included so-called semi-vegetarians, who ate meat at least once a month (but no more than once a week), so it's not yet clear how harmful eating meat a few times a month is. What we can all agree on, though, is that we should limit our intake of junk food and animal fat, and eat more fruits and vegetables. Most authorities will also agree that diets should include whole grains, beans, and nuts. Instead of fighting over whose diet is the best, it's time to acknowledge these common features of diets associated with less disease, and instead focus our attention on helping patients avoid the intense commercial pressures to eat otherwise.

How amazing the human body is if we just treat it right! For more on lifestyle medicine, see:

So please don't allow the perfect to become the enemy of the good. Any movement we can make towards improving our diet can help. Though the earlier the better: See Heart Disease Starts in Childhood and Back in Circulation: Sciatica and Cholesterol.

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: victorpr / 123RF

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Which Dietary Factors Affect Breast Cancer Most?

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One of my favorite cancer-specific charities, the American Institute for Cancer Research, lauds the China Study and the documentary Forks Over Knives, with which they share the same bottom-line message: The healthiest diets are those that revolve around whole plant foods.

They then translate that advice into their Ten Recommendations for Cancer Prevention, featured in my video Which Dietary Factors Affect Breast Cancer Most? We now have evidence that those who follow such advice are actually protected against cancer. Breast cancer risk was reduced by 60% in women who met at least five recommendations compared with those who met none. The most important dietary advice was to be as lean as possible within the normal range of body weight, eat mostly foods of plant origin, and limit alcoholic drinks.

What about other cancers? Greater adherence to the AICR dietary guidelines was also associated with significantly less endometrial, colorectal, lung, kidney, stomach, oral, liver, and esophageal cancer. In other words, adherence to dietary recommendations for cancer prevention may lower the risk of developing most types of cancer. The drop in bladder cancer did not reach statistical significance, but a larger follow-up study following 469,000 people for 11 years (the largest to date) found that just a 3% increase in the consumption of animal protein calories was associated with a 15% higher risk of bladder cancer, whereas just a 2% increase in plant protein was associated with a 23% lower risk.

AICR recommendation number ten is that cancer survivors should follow the recommendations for cancer prevention. The same diet that can help prevent cancer in the first place can be used to help save our life after diagnosis. Adherence to the guidelines for cancer prevention was found to be associated with lower mortality among older female cancer survivors, or breast cancer and other cancers in general.

A cancer diagnosis is considered a teachable moment to get people eating and living healthier. Oncologists revel at the growth in the number of cancer survivors in this country, now ten million strong and growing. It's great that those with cancer are living longer, but even better to prevent it in the first place so we can all live longer. Not only does adherence to the guidelines lower cancer risk, but extends our lifespan because the guidelines are also significantly associated with a lower hazard of dying from heart disease and respiratory disease, suggesting that following the recommendations could "significantly increase longevity."

Just like eating to prevent cancer helps to prevent heart disease, eating to protect our heart helps prevent cancer. It sounds self-evident, but adherence to a healthy lifestyle is therefore associated with a lower risk of mortality overall. And the more healthy behaviors we have, the longer we get to live. Such factors included not smoking, walking every day, or eating green leafy vegetables almost daily.

To help differentiate the effects of diet from other lifestyle behaviors like smoking and drinking on cancer incidence, Adventists were recently compared to Baptists. Both discourage alcohol and tobacco, but the Adventists go further, encouraging a reduction of meat. In general, the Adventists had lower cancer hazard rates than the Baptists, and within Adventist populations, the vegetarians did even better, and those eating the most plants, did the best.

Why do plant-based diets appear to lower the risk of cancer? A number of fascinating mechanisms:

Specific to breast cancer:

Though plant-based beverages may be harmful: Breast Cancer and Alcohol: How Much Is Safe?

In terms of foods associated with breast cancer survival, 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--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: MesserWoland

Image Credit: [Lev Kropotov] © 123RF.com

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Should Pregnant Women Drink Cow’s Milk?

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Foods of animal origin in general naturally contain hormones, but cow's milk may be of particular concern. The hormones naturally found even in organic cow's milk may have played a role in studies that found a relationship between dairy products and human illnesses, such as acne, certain cancers and male reproductive disorders. Milk consumption has also been associated with an increased risk of early puberty and endometrial cancer in postmenopausal women, but "hormonal levels in food could be particularly dangerous in the case of vulnerable populations, such as young children or pregnant women. To this critical population, even a small hormonal intake could lead to major changes in the metabolism."

If you check out my video Why Do Vegan Women Have 5x Fewer Twins, you can see that children are highly sensitive to sex steroids. Because their levels of sex steroids are very low, even a small variation would account for a major change in the total activity of the involved hormone. Because no lower threshold for estrogenic action has been established, caution should be taken to avoid unnecessary exposure of fetuses and children to exogenous sex steroids, even at very low levels.

In the AMA's Pediatrics Journal, the Chair of Boston Children's Hospital's Obesity Prevention Center along with the chair of Harvard's nutrition department questioned dairy industry recommendations that children should drink three glasses of milk a day. Dairy milk evolved to promote the growth of grazing animals at high risk for predation when small, so they needed to put on a few hundred pounds quickly in the first few months of life.

The consequences of lifetime human exposure to the growth factors in milk have not been well studied. "Milk consumption increases serum concentrations of insulin-like growth factor 1, which is linked to prostate and other cancers. In addition, modern industrial methods maintain dairy cows in active milk production throughout their pregnancies, resulting in a milk supply with high levels of reproductive hormones."

Pregnant cows excrete significantly higher levels of sex steroids into their milk than non-pregnant cows. The subsequent consumption of such dairy products from pregnancy results in additional consumer exposure. And it's not just dairy. Although dairy products are an important source of hormones, other products of animal origin must be considered as well. All edible tissues of animal origin contain estrogen. This may explain why, in a study of over a thousand women eating plant-based diets, vegan women have a twinning rate that is one fifth that of vegetarians and omnivores.

Twin pregnancies are risky pregnancies, with much higher complication rates. Many parents and physicians underestimate the negative consequences of multiple pregnancy, but "women with a multiple pregnancy face greater risks for themselves and their infants." Twin babies may be ten times more likely to die at birth. To avoid these complications, the research team writes, "women attempting conception should avoid milk and dairy products."

Minimizing dairy, our nation's #1 source of saturated fat may be a good idea for dads too: Dairy Estrogen and Male Fertility.

What about the endocrine-disrupting xenoestrogens--how do they compare with the natural hormones in our food supply? That was the topic of my video Estrogen in Meat, Dairy, and Eggs.

Then once they're born, best to stick to human milk:

Then as young children, dairy can sometimes cause another problem: Childhood Constipation and Cow's Milk

Here's a selection of other pregnancy-related videos:

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: LivingLandscapeArchitecture / Flickr

Original Link

GMO Soy and Breast Cancer

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In response to concerns raised about the toxicity of Monsanto's roundup pesticide, which ends up in GMO foods (See Is Monsanto's Roundup Pesticide Glyphosate Safe?), Monsanto's scientists countered that these in vitro experiments used physiological irrelevant concentrations, meaning dripping roundup on cells in a petri dish at levels far above what would be realistically found in the human body.

Sure, it's probably not a good idea to mix up your alcohol with your roundup and chug the stuff, or try to commit suicide by drinking or injecting it. And there are rare cases of Parkinson's reported after getting directly sprayed with it, or working for years in a pesticide production plant, but that's not your typical consumer exposure.

As shown in my video GMO Soy and Breast Cancer, some of the researchers responded to the accusation claiming they used the kinds of concentrations that are used out in the fields. Therefore every little droplet we spray worldwide is above the threshold concentration they found to cause adverse effects. Monsanto's folks responded saying, "Yes, that's the concentration we spray, but that's not the concentration that human cells are bathing in. Once it gets into drinking water or food, it's highly diluted." And, they're quick to point out, if we look at people with the greatest exposure--pesticide workers--the vast majority of studies show no link between the use of Roundup and cancer or non-cancer diseases. There are a few suggestive findings suggesting a link with non-Hodgkin's lymphoma. One study of pesticide applicators suggested an association with multiple myeloma, and one study of the children of pesticide applicators found a tentative association with ADHD, but again these are folks experiencing a much greater exposure level than the general population that may just get a few parts per million in their food. But there had never been any studies done on the tiny levels found circulating in people's bodies, until now.

In a study out of Thailand, the maximum residue levels were set at parts per million (the concentrations found within human bodies is measured in parts per billion). The study found glyphosate can activate estrogen receptors at a few parts per trillion, increasing the growth of estrogen receptor positive human breast cancer cells in a petri dish. These results indicate "that truly relevant concentrations of the pesticide found on GMO soybeans possesses estrogenic activity."

But consumption of soy is associated with lower breast cancer risk (See BRCA Breast Cancer Genes and Soy), and improved breast cancer survival (See Breast Cancer Survival and Soy).

That may be because most GMO soy in the U.S. is fed to chickens, pigs, and cows as livestock feed, whereas most of the major soy food manufacturers use non-GMO soy. Or it could be because the benefits of eating any kind of soy may far outweigh the risks, but why accept any risk at all when we can choose organic soy products, which by law exclude GMOs.

The bottom-line is that there is no direct human data suggesting harm from eating GMOs, though in fairness such studies haven't been done, which is exactly the point that critics counter. This is why we need mandatory labeling on GMO products so that public health researchers can track whether GMOs are having any adverse effects.

It is important to put the GMO issue in perspective though. As I've shown (See Lifestyle Medicine: Treating the Causes of Disease), there are dietary and lifestyle changes we can make that could eliminate most heart disease, strokes, diabetes, and cancer. Millions of lives could be saved. A healthy enough diet can even reverse our number one killer, heart disease. So, I'm sympathetic to the biotech industry's exasperation about GMO concerns when we still have people dropping dead from everything else they're eating. As one review concluded "consumption of genetically modified food entails risk of undesirable effects... similar to the consumption of traditional food." In other words, buying the non-GMO Twinkie isn't doing our body much of a favor.

For more on the public health implications of genetically engineered crops in our food supply, check out the these videos:

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: Nesbitt_Photo / Flickr

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Preventing Breast Cancer with Flax Seeds

NF-May24 Can Flax Seeds Help Prevent Breast Cancer?.jpeg

I've previously discussed the role of dietary lignans in the reduction of breast cancer risk and improvement in breast cancer survival, based on studies that showed that women with breast cancer who ate the most lignans appeared to live longer (Flaxseeds & Breast Cancer Survival: Epidemiological Evidence and Flaxseeds & Breast Cancer Survival: Clinical Evidence). However, lignans are found throughout the plant kingdom--in seeds, whole grains, vegetables, fruits, berries--so how do we know lignans aren't merely a marker for the intake of unrefined plant foods? For example, those who eat lots of plants--vegetarians--have about eight times the lignan intake than omnivores.

In a petri dish, lignans have been shown to both have direct anticancer growth activity against human breast cancer cells and to prevent cancer cell migration. But it wasn't until 2005 that it was put to the test in people. Researchers from the University of Toronto conducted a randomized double-blind placebo-controlled clinical trial (as seen in my video, Can Flax Seeds Help Prevent Breast Cancer?) of flaxseeds, the world's most concentrated source of lignans in breast cancer patients. The researchers found that flax appears to have the potential to reduce human breast tumor growth in just a matter of weeks. Therefore, I started recommending ground flax seeds to breast cancer patients.

Can lignans also help prevent breast cancer in the first place? High lignan intake is associated with reduced breast cancer risk, but again lignan intake may just be saying an indicator of high plant food intake in general. So researchers from the University of Kansas gave women at high risk for breast cancer a teaspoon of ground flaxseeds a day for a year, and found on average a drop in precancerous changes in the breast.

What about women who regularly eat flax seeds? Outside of an experimental setting, there just weren't a lot of women eating flax seeds regularly to study--until now. Matching 3,000 women with breast cancer to 3,000 women without, a study published in Cancer Causes and Control found that consumption of flaxseed (and of flax bread) was associated with a 20-30 percent reduction in breast cancer risk. The researchers note that, as flaxseeds are packed with lignans, only a small daily serving of flaxseed is required to attain the level of lignan intake associated with a reduction in breast cancer risk. Researchers concluded: "As it appears that most women do not consume flaxseed and that small amounts may be associated with reduced breast cancer risk, interventions to increase the prevalence of flaxseed consumption might be considered."

The latest review summarizes the association between flax and decreased risk of breast cancer, better mental health, and lower mortality among breast cancer patients. The only other study of flax and brain health I'm aware of was an exploration of 100 commonly used drugs and supplements on cognition in older adults, which found that flax is one of the few things that appears to help.

How else may flaxseeds aid in preventing and treating breast cancer? There's an inflammatory molecule called interleukin-1, which may help tumors feed, grow, and invade. Our bodies therefore produce an interkeukin-1 receptor antagonist, binding to the IL-1 receptor and blocking the action of IL-1. The activity of this protective inhibitor can be boosted with the drug tamoxifen--or by eating flax seed. In premenopausal women, the proinflammatory profile of interleukin-1 can be counteracted by a dietary addition of a few spoonfuls of ground flax. One month of flax may be able to increase the anti-inflammatory inhibitor levels by over 50 percent, better even than the drug.

Yes, having one's ovaries removed may reduce breast cancer risk as much as 60 percent, but at the cost of severe side-effects. The drug tamoxifen may reduce the incidence of breast cancer by more than 40 percent, but may induce other severe side effects such as uterine cancer and blood clots. That's why less toxic (even safe!) breast cancer preventive strategies such as dietary modifications need to be developed. These lignan phytoestrogens in flaxseeds may be one successful route given the data showing reduced breast cancer risk and improved overall survival.

Lignans are not a magic bullet to prevent breast cancer--we can't just sprinkle some flax on your bacon cheeseburger--but as a part of a healthy diet and life-style, they might help to reduce breast cancer risk in the general population.

Flaxseeds may also help fight hormone-mediated cancers in men. See Flaxseed vs. Prostate Cancer and Was It the Flaxseed, Fat Restriction, or Both?

What else can these puppies do? See:

I have another 100+ videos on breast cancer if you want to become an expert and help take care of yourself and/or the women in your life. Here's a few recent ones to get you started:

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: Alisha Vargas / Flickr

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