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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In health,
Michael Greger, M.D.

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

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

Original Link

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In health,
Michael Greger, M.D.

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

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

Original Link

Reducing Glycotoxin Intake to Help Reduce Brain Loss

Reducing Glycotoxin Intake to Prevent Alzheimer's.jpg

Each of us has about six billion miles of DNA. How does our body keep it from getting all tangled up? There are special proteins called histones, which act like spools with DNA as the thread. Enzymes called sirtuins wrap the DNA around the histones and by doing so, silence whatever genes were in that stretch of DNA, hence their name SIRtuins, which stands for silencing information regulator.

Although they were discovered only about a decade ago, the study of sirtuins "has become one of the most promising areas of biomedicine," since they appear to be involved in promoting healthy aging and longevity. Suppression of this key host defense is considered a central feature of Alzheimer's disease, as shown in Reducing Glycotoxin Intake to Prevent Alzheimer's.

Autopsies of Alzheimer's victims reveal that loss of sirtuin activity is closely associated with the accumulation of the plaques and tangles in the brain that are characteristic of Alzheimer's disease. Sirtuin appears to activate pathways that steer the brain away from the formation of plaque and tangle proteins. "Because a decrease in sirtuin activity can clearly have deleterious effects" on nerve health, researchers are trying to come up with drugs to increase sirtuin activity, but why not just prevent its suppression in the first place?

Glycotoxins in our food suppress sirtuin activity, also known as advanced glycation end products, or AGE's. Our modern diet includes excessive AGE's, which can be neurotoxic. High levels in the blood may predict cognitive decline over time. If you measure the urine levels of glycotoxins flowing through the bodies of older adults, those with the highest levels went on to suffer the greatest cognitive decline over the subsequent nine years.

As we age, our brain literally shrinks. In our 60's and 70's, we lose an average of five cubic centimeters of total brain tissue volume every year, but some people lose more than others. Brain atrophy may be reduced in very healthy individuals, and a few people don't lose any brain at all. Normally we lose about 2% of brain volume every year, but that's just the average. Although the average brain loss for folks in their 70's and 80's was 2.1%, some lost more, some lost less, and some men and women lost none at all over a period of four years.

Researchers in Australia provided the first evidence linking AGEs with this kind of cerebral brain loss. So, limiting one's consumption of these compounds may end up having significant public health benefits. Because sirtuin deficiency is both preventable and reversible by dietary AGE reduction, a therapeutic strategy that includes eating less AGE's may offer a new strategy to combat the epidemic of Alzheimer's.

Some glycotoxins are produced internally, particularly in diabetics, but anyone can get them from smoking and eating, particularly foods high in fat and protein cooked at high temperatures. In my video, Avoiding a Sugary Grave, I listed the 15 foods most contaminated with glycotoxins; mostly chicken, but also pork, beef, and fish, which may help explain why those that eat the most meat may have triple the risk of getting dementia compared to long-time vegetarians. Note there are some relatively high fat and protein plant foods such as nuts and soy products, so I no longer recommend toasting nuts and would steer clear from roasted tofu.

I've covered advanced glycation end-products in Glycotoxins, Bacon, Eggs, and Gestational Diabetes During Pregnancy, and Why is Meat a Risk Factor for Diabetes?.

More on slowing brain aging in How to Slow Brain Aging By Two Years.

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: lightwise © 123RF.com. This image has been modified.

Original Link

Reducing Glycotoxin Intake to Help Reduce Brain Loss

Reducing Glycotoxin Intake to Prevent Alzheimer's.jpg

Each of us has about six billion miles of DNA. How does our body keep it from getting all tangled up? There are special proteins called histones, which act like spools with DNA as the thread. Enzymes called sirtuins wrap the DNA around the histones and by doing so, silence whatever genes were in that stretch of DNA, hence their name SIRtuins, which stands for silencing information regulator.

Although they were discovered only about a decade ago, the study of sirtuins "has become one of the most promising areas of biomedicine," since they appear to be involved in promoting healthy aging and longevity. Suppression of this key host defense is considered a central feature of Alzheimer's disease, as shown in Reducing Glycotoxin Intake to Prevent Alzheimer's.

Autopsies of Alzheimer's victims reveal that loss of sirtuin activity is closely associated with the accumulation of the plaques and tangles in the brain that are characteristic of Alzheimer's disease. Sirtuin appears to activate pathways that steer the brain away from the formation of plaque and tangle proteins. "Because a decrease in sirtuin activity can clearly have deleterious effects" on nerve health, researchers are trying to come up with drugs to increase sirtuin activity, but why not just prevent its suppression in the first place?

Glycotoxins in our food suppress sirtuin activity, also known as advanced glycation end products, or AGE's. Our modern diet includes excessive AGE's, which can be neurotoxic. High levels in the blood may predict cognitive decline over time. If you measure the urine levels of glycotoxins flowing through the bodies of older adults, those with the highest levels went on to suffer the greatest cognitive decline over the subsequent nine years.

As we age, our brain literally shrinks. In our 60's and 70's, we lose an average of five cubic centimeters of total brain tissue volume every year, but some people lose more than others. Brain atrophy may be reduced in very healthy individuals, and a few people don't lose any brain at all. Normally we lose about 2% of brain volume every year, but that's just the average. Although the average brain loss for folks in their 70's and 80's was 2.1%, some lost more, some lost less, and some men and women lost none at all over a period of four years.

Researchers in Australia provided the first evidence linking AGEs with this kind of cerebral brain loss. So, limiting one's consumption of these compounds may end up having significant public health benefits. Because sirtuin deficiency is both preventable and reversible by dietary AGE reduction, a therapeutic strategy that includes eating less AGE's may offer a new strategy to combat the epidemic of Alzheimer's.

Some glycotoxins are produced internally, particularly in diabetics, but anyone can get them from smoking and eating, particularly foods high in fat and protein cooked at high temperatures. In my video, Avoiding a Sugary Grave, I listed the 15 foods most contaminated with glycotoxins; mostly chicken, but also pork, beef, and fish, which may help explain why those that eat the most meat may have triple the risk of getting dementia compared to long-time vegetarians. Note there are some relatively high fat and protein plant foods such as nuts and soy products, so I no longer recommend toasting nuts and would steer clear from roasted tofu.

I've covered advanced glycation end-products in Glycotoxins, Bacon, Eggs, and Gestational Diabetes During Pregnancy, and Why is Meat a Risk Factor for Diabetes?.

More on slowing brain aging in How to Slow Brain Aging By Two Years.

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: lightwise © 123RF.com. This image has been modified.

Original Link

The Natural Human Diet

NF-Nov15 The Problem with the Paleo Diet Argument copy.jpg

Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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: Nathan Rupert / Flickr

Original Link

The Natural Human Diet

NF-Nov15 The Problem with the Paleo Diet Argument copy.jpg

Our epidemics of dietary disease have prompted a great deal of research into what humans are meant to eat for optimal health. In 1985, an influential article highlighted in my video The Problem With the Paleo Diet Argument was published proposing that our chronic diseases stem from a disconnect between what our bodies ate while evolving during the Stone Age (about 2 million years ago) and what we're stuffing our face with today. The proposal advocated for a return towards a hunter-gatherer type diet of lean meat, fruits, vegetables, and nuts.

It's reasonable to assume our nutritional requirements were established in the prehistoric past. However, the question of which prehistoric past we should emulate remains. Why just the last 2 million? We've been evolving for about 20 million years since our last common great ape ancestor, during which our nutrient requirements and digestive physiology were set down. Therefore our hunter-gatherer days at the tail end probably had little effect. What were we eating for the first 90% of our evolution? What the rest of the great apes ended up eating--95 percent or more plants.

This may explain why we're so susceptible to heart disease. For most of human evolution, cholesterol may have been virtually absent from the diet. No bacon, butter, or trans fats; and massive amounts of fiber, which pulls cholesterol from the body. This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolve not only to make cholesterol, but also to preserve it and recycle it.

If we think of the human body as a cholesterol-conserving machine, then plop it into the modern world of bacon, eggs, cheese, chicken, pork, and pastry; it's no wonder artery-clogging heart disease is our #1 cause of death. What used to be adaptive for 90% of our evolution--holding on to cholesterol at all costs since we weren't getting much in our diet--is today maladaptive, a liability leading to the clogging of our arteries. Our bodies just can't handle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. We can feed a dog 500 eggs worth of cholesterol and they just wag their tail; a dog's body is used to eating and getting rid of excess cholesterol. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet.

Even if our bodies were designed by natural selection to eat mostly fruit, greens and seeds for 90% of our evolution, why didn't we better adapt to meat-eating in the last 10%, during the Paleolithic? We've had nearly 2 million years to get used to all that extra saturated fat and cholesterol. If a lifetime of eating like that clogs up nearly everyone's arteries, why didn't the genes of those who got heart attacks die off and get replaced by those that could live to a ripe old age with clean arteries regardless of what they ate? Because most didn't survive into old age.

Most prehistoric peoples didn't live long enough to get heart attacks. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation. The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage (as would discovering a time machine stash of Twinkies for that matter!). If we only have to live long enough to get our kids to puberty to pass along our genes, then we don't have to evolve any protections against the ravages of chronic disease.

To find a population nearly free of chronic disease in old age, we don't have to go back a million years. In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent, and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. In a sense, these populations in rural China and Africa were eating the type of diet we've been eating for 90% of the last 20 million years, a diet almost exclusively of plant foods.

How do we know it was their diet and not something else? In the 25 year update to their original paleo paper, the authors tried to clarify that they did not then and do not now propose that people adopt a particular diet just based on what our ancient ancestors ate. Dietary recommendations must be put to the test. That's why the pioneering research from Pritikin, Ornish, and Esselstyn is so important, showing that plant-based diets can not only stop heart disease but have been proven to reverse it in the majority of patients. Indeed, it's the only diet that ever has.

For more on the absence of Western diseases in plant-based rural populations, see for example:

I've touched on "paleo" diets in the past:

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: Nathan Rupert / Flickr

Original Link

What to Eat to Protect Against Kidney Cancer

NF-Sept8 Can Diet Protect Against Kidney Cancer_.jpeg

58,000 Americans are diagnosed with kidney cancer every year, and 13,000 die. And the numbers have been going up. Approximately 4 percent of cases are hereditary, but what about the other 96 percent? The only accepted risk factor has been tobacco use, but cigarette smoking has been declining.

Nitrosamines are one of the most potent carcinogens in cigarette smoke. One hot dog has as many nitrosamines and nitrosamides as five cigarettes. And these carcinogens are also found in fresh meat as well: beef, chicken and pork. So even though smoking rates have dropped, perhaps the rise in kidney cancer over the last few decades may have something to do with meat consumption. But would kidney cancer just be related to the processed meats like bacon, sausage, hot dogs and cold cuts that have nitrate and nitrite additives, or fresh meat as well?

The NIH-AARP study featured in my video Can Diet Protect Against Kidney Cancer? is the largest prospective study on diet and health ever performed--about 500,000 followed for nine years. In addition to examining nitrate and nitrite intake from processed meat, they also looked at intake from other sources such as fresh meat, eggs and dairy. Nitrite from animal sources, not just processed meats, was associated with an increased risk of kidney cancer, and total intake of nitrate and nitrite from processed meat sources was also associated with kidney cancer risk. The researchers found no associations with nitrate or nitrite intake from plant sources, but nitrates from processed meat was associated with cancer.

When meat producers advertise their bacon or lunch meat as "uncured," this means no nitrites or nitrates added. But if you look at the small print you'll see something like, "except for celery juice." That's just a sneaky way to add nitrites. Processed meat producers ferment the nitrates in celery to create nitrites, then add it to the meat; a practice even the industry admits "may be viewed as incorrect at best or deceptive at worst."

But that same fermentation of nitrates to nitrites can happen thanks to bacteria on our tongue when we eat vegetables. So why are nitrates and nitrites from vegetables on our tongue harmless, but nitrates and nitrites from vegetables in meat linked to cancer? The actual carcinogens are not nitrites, but nitrosamines and nitrosamides. In our stomach, to turn nitrites into nitros-amines, and nitros-amides we need amines and amides, which are concentrated in animal products. And vitamin C and other antioxidants in plant foods block the formation of these carcinogens in our stomach. That's why we can safely benefit from the nitrates in vegetables without the cancer risk. In fact some of the highest nitrate vegetables like arugula, kale, and collards are associated with decreased risk of kidney cancer. The more plants, it appears, the better.

Plant-based diets and fiber-rich diets are recommended to prevent cancer directly, as well as chronic conditions associated with kidney cancer, such as obesity, high blood pressure and diabetes. It's similar to sodium intake and kidney cancer. Sodium intake increases kidney disease risk, but that's not just because sodium intake increases blood pressure. It appears the salt is associated with increased cancer risk even independently of hypertension. What about plant-based diets? Turns out the protective association remains even in people who are not obese and have normal blood pressure. So overall, plant-based and fiber-rich diets appear to do both: decrease cancer risk directly and indirectly.

I briefly address kidney health in Preventing Kidney Failure Through Diet and Treating Kidney Failure Through Diet, but have a whole series of more in-depth videos dealing with various kidney issues.

More on the fascinating nitrate/nitrite story in my 17-part series about improving athletic performance with nitrate-rich vegetables such as beets and arugula. Here are a few short highlights:

More on carcinogens caused by cooking meat in videos like:

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: RDSVS / Flickr

Original Link

Paleo Diet May Undermine Benefit of CrossFit Exercise

NF-Sept6 Paleo Diets May Negate Benefits of Exercise.jpeg

Much of the low-carb and paleo reasoning revolves around insulin. To quote a paleo blogger, "carbohydrates increase insulin, the root of all evil when it comes to dieting and health." So the logic follows that because carbs increase insulin, we should stick mostly to meat, which is fat and protein with no carbs, so no increase in insulin, right?

Wrong.

We've known for half a century that if you give someone just a steak: no carbs, no sugar, no starch; their insulin goes up. Carbs make our insulin go up, but so does protein.

In 1997 an insulin index of foods was published, ranking 38 foods to determine which stimulates higher insulin levels. Researchers compared a large apple and all its sugar, a cup of oatmeal packed with carbs, a cup and a half of white flour pasta, a big bun-less burger with no carbs at all, to half of a salmon fillet. As you can see in the graph in my video Paleo Diets May Negate Benefits of Exercise, the meat produced the highest insulin levels.

Researchers only looked at beef and fish, but subsequent data showed that that there's no significant difference between the insulin spike from beef, chicken, or pork--they're all just as high. Thus, protein and fat rich foods may induce substantial insulin secretion. In fact, meat protein causes as much insulin release as pure sugar.

So, based on the insulin logic, if low-carbers and paleo folks really believed insulin to be the root of all evil, then they would be eating big bowls of spaghetti day in and day out before they would ever consume meat.

They are correct in believing that having hyperinsulinemia, high levels of insulin in the blood like type 2 diabetics have, is not a good thing, and may increase cancer risk. But if low-carb and paleo dieters stuck to their own insulin theory, then they would be out telling everyone to start eating plant-based. Vegetarians have significantly lower insulin levels even at the same weight as omnivores. This is true for ovo-lacto-vegetarians, lacto-vegetarians, and vegans. Meat-eaters have up to 50% higher insulin levels.

Researchers from the University of Memphis put a variety of people on a vegan diet (men, women, younger folks, older folks, skinny and fat) and their insulin levels dropped significantly within just three weeks. And then, just by adding egg whites back to their diet, their insulin production rose 60% within four days.

In a study out of MIT, researchers doubled participants' carbohydrate intake, and their insulin levels went down. Why? Because the researchers weren't feeding people jellybeans and sugar cookies, they were feeding people whole, plant foods, lots of whole grains, beans, fruits, and vegetables.

What if we put someone on a very-low carb diet, like an Atkins diet? Low carb advocates such as Dr. Westman assumed that it would lower insulin levels. Dr. Westman is the author of the new Atkins books, after Dr. Atkins died obese with, according to the medical examiner, a history of heart attack, congestive heart failure, and hypertension. But, Dr. Westman was wrong in his assumption. There are no significant drop in insulin levels on very low-carb diets. Instead, there is a significant rise in LDL cholesterol levels, the number one risk factor for our number one killer, heart disease.

Atkins is an easy target though. No matter how many "new" Atkins diets that come out, it's still old news. What about the paleo diet? The paleo movement gets a lot of things right. They tell people to ditch dairy and doughnuts, eat lots of fruits, nuts, and vegetables, and cut out a lot of processed junk food. But a new study published in the International Journal of Exercise Science is pretty concerning. Researchers took young healthy people, put them on a Paleolithic diet along with a CrossFit-based, high-intensity circuit training exercise program.

If you lose enough weight exercising, you can temporarily drop our cholesterol levels no matter what you eat. You can see that with stomach stapling surgery, tuberculosis, chemotherapy, a cocaine habit, etc. Just losing weight by any means can lower cholesterol, which makes the results of the Paleo/Crossfit study all the more troubling. After ten weeks of hardcore workouts and weight loss, the participants' LDL cholesterol still went up. And it was even worse for those who started out the healthiest. Those starting out with excellent LDL's (under 70), had a 20% elevation in LDL cholesterol, and their HDL dropped. Exercise is supposed to boost our good cholesterol, not lower it.

The paleo diet's deleterious impact on blood fats was not only significant, but substantial enough to counteract the improvements commonly seen with improved fitness and body composition. Exercise is supposed to make things better.

On the other hand, if we put people instead on a plant-based diet and a modest exercise program, mostly just walking-based; within three weeks their bad cholesterol can drop 20% and their insulin levels 30%, despite a 75-80% carbohydrate diet, whereas the paleo diets appeared to "negate the positive effects of exercise."

I touched on paleo diets before in Paleolithic Lessons, and I featured a guest blog on the subject: Will The Real Paleo Diet Please Stand Up?

but my favorite paleo videos are probably The Problem With the Paleo Diet Argument and Lose Two Pounds in One Sitting: Taking the Mioscenic Route.

I wrote a book on low carb diets in general (now available free full-text online) and touched on it in Atkins Diet: Trouble Keeping It Up and Low Carb Diets and Coronary Blood Flow.

And if you're thinking, but what about the size of the cholesterol, small and dense versus large and fluffy? Please see my video Does Cholesterol Size Matter?

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: Vincent Lit / Flickr

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The Effects of Dietary Cholesterol on Blood Cholesterol

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Blood cholesterol levels are clearly increased by eating dietary cholesterol. In other words, putting cholesterol in our mouth means putting cholesterol in our blood, and it may also potentiate the harmful effects of saturated fats, meaning when we eat sausage and eggs, the eggs may make the effects of the sausage even worse. If you eat the saturated fat and cholesterol found in two sausages and egg McMuffins every day for two weeks, your cholesterol would shoot up nearly 30 points. If you ate about the same saturated fat without the cholesterol, some kind of cholesterol-free sausage McMuffins without the egg, what would happen? Now the egg would have saturated fat too, so to even it out we have to add three strips of bacon to the comparison. Same saturated fat, but two-eggs-worth less cholesterol, would only bump us up only around five points. So, saturated fat may increase fasting cholesterol levels more than dietary cholesterol, but especially in the presence of dietary cholesterol.

And this is measuring fasting cholesterol, meaning the baseline from which all our meal-related cholesterol spikes would then shoot. Heart disease has been described as a postprandial phenomenon, meaning an after-meal phenomenon. Milky little droplets of fat and cholesterol straight from a meal called chylomicrons can build up in atherosclerotic plaques just like LDL cholesterol. So what happens after a meal that includes eggs?

In my video How the Egg Board Designs Misleading Studies, you can see what happens to the level of fat and cholesterol in our blood stream for the seven hours after eating a meal with no-fat, no-cholesterol. There are hardly changes at all. But when you eat a meal with fat and more and more egg, triglycerides and blood cholesterol shoot up.

That's the kind of data that's bad for egg sales, so how could you design a study to hide this fact?

What if you only measured fasting cholesterol levels in the morning, seven hours after supper? You wouldn't see a big difference between those that ate eggs the night before and those that didn't. As the lead investigator of a study which compared the cardiovascular health effects of smoking versus eating eggs pointed out, measuring fasting cholesterol is appropriate for measuring the effects of drugs suppressing our liver's cholesterol production, but not appropriate for measuring the effects of dietary cholesterol. After a cholesterol-laden supper, our arteries are being pummeled all night long. Then think about what's happening during the day. There may be only four hours between breakfast and lunch. So if we had eggs for breakfast we'd get that big spike and by lunch start the whole cycle of fat and cholesterol in our arteries all over again. So most of our lives are lived in a postprandial state, in an after-meal state, and the graph I show in the video shows that the amount of egg in our meals makes a big difference when it really matters--after we've eaten, which is where we spend most of our lives. So that's why when the Egg Board funds a study, they only measure fasting cholesterol levels of the next day.

Doctors are so used to testing fasting cholesterol levels to monitor the effects of drugs, they too often fall for these egg industry tactics hook, line, and sinker. Please share the video with anyone who tries to downplay the risks of eggs or dietary cholesterol in general.

The smoking study I mentioned can be found here: Eggs vs. Cigarettes in Atherosclerosis.

For more videos on eggs for those who just desperately cling to egg industry propaganda, please see a few of my latest:

For another jaw-dropper as to the gall of corporate interests to use the veneer of science to downplay the risks of their products, check out BOLD Indeed: Beef Lowers 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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

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Antibiotic-Resistant "Superbugs" in Meat

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As a rule, "high-ranking public-health officials try to avoid apocalyptic descriptors. So it's worrying to hear those like the Director of the CDC warn of a coming health 'nightmare' and a 'catastrophic threat.'" A number of prominent publications recently warned of the threat of antibiotic resistance. The CDC estimates that at a minimum, more than two million people are sickened every year with antibiotic-resistant infections in the United States, with at least 23,000 dying as a result (See MRSA Superbugs in Meat).

We may be at the dawn of a post-antibiotic era. Achievements in modern medicine that we today take for granted, such as surgery and the treatment of preterm babies, would not be possible without access to effective treatment for bacterial infections. For example, without antibiotics, the rate of postoperative infection after a procedure like a hip replacement would be 40-50% and about one in three of those patients would die. So the so-called worst case scenarios where resistant infections could cost $50 billion a year might still be an underestimate. "From cradle to grave, antibiotics have become pivotal in safeguarding the overall health of human societies."

So the dire phrasing from head officials may be warranted. There are now infections like carbapenem-resistant enterobacter that are resistant to nearly all antibiotics, even to so-called drugs of last resort. Worryingly, some of these last resort drugs are being used extensively in animal agriculture.

According to the World Health Organization, more antibiotics are fed to farmed animals than are used to treat disease in human patients. Doctors overprescribe antibiotics, but huge amounts of antibiotics are used in fish farming and other intensive animal agriculture, up to four times the amount used in human medicine. Why? "Suboptimum growth to slaughter weight caused by unsanitary conditions can be compensated with the addition of antibiotics to feed." Instead of relieving any stressful overcrowded unhygienic conditions, it may be cheaper to just dose the animals with drugs.

In this way, factory farms are driving the growth of antibiotic-resistant organisms that cause human diseases. "This may help bolster the industry's bottom line, but in the process, bacteria are developing antimicrobial resistance, which affects human health."

In the United States, the FDA reports that 80% of antimicrobial drugs in the United States are used in food animals, mainly to promote growth in this kind of high-density production. This can select for antibiotic-resistant bacteria like methicillin-resistant Staph aureus, or MRSA, considered a serious threat in the United States.

These industrial pig operations may provide optimal conditions for the introduction and transmission of MRSA. U.S. pork producers are currently permitted to use 29 antibiotic drugs in feed--all without a prescription. Antiobitics are currently added to about 90% of pigs starter feeds.

When animals receive unnecessary antibiotics, bacteria can be come resistant to the drugs, then travel on meat to the store, and end up causing hard-to-treat illnesses in people.

MRSA present in retail raw meat may serve as a possible source of bacterial infections of food preparers in the food industry and the hands of consumers in the home. Once MRSA gets into our homes on meat, it can transfer to our cutting boards, knives, and onto our skin at a rate similar to the rate of transmission from touching an infected patient contaminated with MRSA. Washing of hands after touching raw pork is advised.

I know I've already covered this topic before, but it never fails to shock me that the meat industry can get away with something so forcefully and universally condemned by the public health community. What other industrial sector could get away with putting people at such risk? It speaks to the combined might of the livestock industry and the pharmaceutical industry in holding sway over our democratic process, no matter what the human health consequences.

If you've missed my other MRSA videos, check out:

And for more on this critical issue in general:

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.

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