What Animal Protein Does in Your Colon

What Animal Protein Does in Your Colon.jpeg

There's a take-off of the industry slogan, "Beef: It's What's For Dinner" - "Beef: It's What's Rotting in Your Colon." I saw this on a shirt once with some friends and I was such the party pooper--no pun intended--explaining to everyone that meat is fully digested in the small intestine, and never makes it down into the colon. It's no fun hanging out with biology geeks.

But I was wrong!

It's been estimated that with a typical Western diet, up to 12 grams of protein can escape digestion, and when it reaches the colon, it can be turned into toxic substances like ammonia. This degradation of undigested protein in the colon is called putrefaction, so a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.

It's generally accepted that carbohydrate fermentation--the fiber and resistant starches that reach our colon--results in beneficial effects because of the generation of short-chain fatty acids like butyrate, whereas protein fermentation is considered detrimental. Protein fermentation mainly occurs in the lower end of colon and results in the production of potentially toxic metabolites. That may be why colorectal cancer and ulcerative colitis tends to happen lower down--because that's where the protein is putrefying.

Probably the simplest strategy to reduce the potential harm of protein fermentation is to reduce dietary protein intake. But the accumulation of these toxic byproducts of protein metabolism may be attenuated by the fermentation of undigested plant matter. In my video, Bowel Wars: Hydrogen Sulfide vs. Butyrate, you can see a study out of Australia showed that if you give people foods containing resistant starch you can block the accumulation of potentially harmful byproducts of protein metabolism. Resistant starch is resistant to small intestine digestion and so it makes it down to our colon where it can feed our good bacteria. Resistant starch is found in cooked beans, split peas, chickpeas, lentils, raw oatmeal, and cooled cooked pasta (like macaroni salad). Apparently, the more starch that ends up in the colon, the less ammonia that is produced.

Of course, there's protein in plants too. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine, which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that may play a role in the development of the inflammatory bowel disease, ulcerative colitis (see Preventing Ulcerative Colitis with Diet).

The toxic effects of hydrogen sulfide appear to be a result of blocking the ability of the cells lining our colon from utilizing butyrate, which is what our good bacteria make from the fiber and resistant starch we eat. It's like this constant battle in our colon between the bad metabolites of protein, hydrogen sulfide, and the good metabolites of carbohydrates, butyrate. Using human colon samples, researchers were able to show that the adverse effects of sulfide could be reversed by butyrate. So we can either cut down on meat, eat more plants, or both.

There are two ways hydrogen sulfide can be produced, though. It's mainly present in our large intestine as a result of the breakdown of sulfur-containing proteins, but the rotten egg gas can also be generated from inorganic sulfur preservatives like sulfites and sulfur dioxide.

Sulfur dioxide is used as a preservative in dried fruit, and sulfites are added to wines. We can avoid sulfur additives by reading labels or by just choosing organic, since they're forbidden from organic fruits and beverages by law.

More than 35 years ago, studies started implicating sulfur dioxide preservatives in the exacerbation of asthma. This so-called "sulfite-sensitivity" seems to affect only about 1 in 2,000 people, so I recommended those with asthma avoid it, but otherwise I considered the preservative harmless. I am now not so sure, and advise people to avoid it when possible.

Cabbage family vegetables naturally have some sulfur compounds, but thankfully, after following more than a hundred thousand women for over 25 years, researchers concluded cruciferous vegetables were not associated with elevated colitis risk.

Because of animal protein and processed food intake, the standard American diet may contain five or six times more sulfur than a diet centered around unprocessed plant foods. This may help explain the rarity of inflammatory bowel disease among those eating traditional whole food, plant-based diets.

How could companies just add things like sulfur dioxide to foods without adequate safety testing? See Who Determines if Food Additives are Safe? For other additives that may be a problem, see Titanium Dioxide & Inflammatory Bowel Disease and Is Carrageenan Safe?

More on this epic fermentation battle in our gut in Stool pH and Colon Cancer.

Does the sulfur-containing amino acid methionine sound familiar? You may remember it from such hits as Starving Cancer with Methionine Restriction and Methionine Restriction as a Life Extension Strategy.

These short-chain fatty acids released by our good bacteria when we eat fiber and resistant starches are what may be behind the second meal effect: Beans and the Second Meal Effect.

I mentioned ulcerative colitis. What about the other inflammatory bowel disease Crohn's? See Preventing Crohn's Disease With Diet and Dietary Treatment of Crohn's Disease.

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 Animal Protein Does in Your Colon

What Animal Protein Does in Your Colon.jpeg

There's a take-off of the industry slogan, "Beef: It's What's For Dinner" - "Beef: It's What's Rotting in Your Colon." I saw this on a shirt once with some friends and I was such the party pooper--no pun intended--explaining to everyone that meat is fully digested in the small intestine, and never makes it down into the colon. It's no fun hanging out with biology geeks.

But I was wrong!

It's been estimated that with a typical Western diet, up to 12 grams of protein can escape digestion, and when it reaches the colon, it can be turned into toxic substances like ammonia. This degradation of undigested protein in the colon is called putrefaction, so a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.

It's generally accepted that carbohydrate fermentation--the fiber and resistant starches that reach our colon--results in beneficial effects because of the generation of short-chain fatty acids like butyrate, whereas protein fermentation is considered detrimental. Protein fermentation mainly occurs in the lower end of colon and results in the production of potentially toxic metabolites. That may be why colorectal cancer and ulcerative colitis tends to happen lower down--because that's where the protein is putrefying.

Probably the simplest strategy to reduce the potential harm of protein fermentation is to reduce dietary protein intake. But the accumulation of these toxic byproducts of protein metabolism may be attenuated by the fermentation of undigested plant matter. In my video, Bowel Wars: Hydrogen Sulfide vs. Butyrate, you can see a study out of Australia showed that if you give people foods containing resistant starch you can block the accumulation of potentially harmful byproducts of protein metabolism. Resistant starch is resistant to small intestine digestion and so it makes it down to our colon where it can feed our good bacteria. Resistant starch is found in cooked beans, split peas, chickpeas, lentils, raw oatmeal, and cooled cooked pasta (like macaroni salad). Apparently, the more starch that ends up in the colon, the less ammonia that is produced.

Of course, there's protein in plants too. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine, which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that may play a role in the development of the inflammatory bowel disease, ulcerative colitis (see Preventing Ulcerative Colitis with Diet).

The toxic effects of hydrogen sulfide appear to be a result of blocking the ability of the cells lining our colon from utilizing butyrate, which is what our good bacteria make from the fiber and resistant starch we eat. It's like this constant battle in our colon between the bad metabolites of protein, hydrogen sulfide, and the good metabolites of carbohydrates, butyrate. Using human colon samples, researchers were able to show that the adverse effects of sulfide could be reversed by butyrate. So we can either cut down on meat, eat more plants, or both.

There are two ways hydrogen sulfide can be produced, though. It's mainly present in our large intestine as a result of the breakdown of sulfur-containing proteins, but the rotten egg gas can also be generated from inorganic sulfur preservatives like sulfites and sulfur dioxide.

Sulfur dioxide is used as a preservative in dried fruit, and sulfites are added to wines. We can avoid sulfur additives by reading labels or by just choosing organic, since they're forbidden from organic fruits and beverages by law.

More than 35 years ago, studies started implicating sulfur dioxide preservatives in the exacerbation of asthma. This so-called "sulfite-sensitivity" seems to affect only about 1 in 2,000 people, so I recommended those with asthma avoid it, but otherwise I considered the preservative harmless. I am now not so sure, and advise people to avoid it when possible.

Cabbage family vegetables naturally have some sulfur compounds, but thankfully, after following more than a hundred thousand women for over 25 years, researchers concluded cruciferous vegetables were not associated with elevated colitis risk.

Because of animal protein and processed food intake, the standard American diet may contain five or six times more sulfur than a diet centered around unprocessed plant foods. This may help explain the rarity of inflammatory bowel disease among those eating traditional whole food, plant-based diets.

How could companies just add things like sulfur dioxide to foods without adequate safety testing? See Who Determines if Food Additives are Safe? For other additives that may be a problem, see Titanium Dioxide & Inflammatory Bowel Disease and Is Carrageenan Safe?

More on this epic fermentation battle in our gut in Stool pH and Colon Cancer.

Does the sulfur-containing amino acid methionine sound familiar? You may remember it from such hits as Starving Cancer with Methionine Restriction and Methionine Restriction as a Life Extension Strategy.

These short-chain fatty acids released by our good bacteria when we eat fiber and resistant starches are what may be behind the second meal effect: Beans and the Second Meal Effect.

I mentioned ulcerative colitis. What about the other inflammatory bowel disease Crohn's? See Preventing Crohn's Disease With Diet and Dietary Treatment of Crohn's Disease.

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

White Meat May Be as Cholesterol-Raising as Red

White Meat May Be as Cholesterol-Raising as Red.jpeg

In light of recommendations for heart healthy eating from national professional organizations encouraging Americans to limit their intake of meat, the beef industry commissioned and co-wrote a review of randomized controlled trials comparing the effects of beef versus chicken and fish on cholesterol levels published over the last 60 years. They found that the impact of beef consumption on the cholesterol profile of humans is similar to that of fish and/or poultry--meaning that switching from red meat to white meat likely wouldn't make any difference. And that's really no surprise, given how fat we've genetically manipulated chickens to be these days, up to ten times more fat than they had a century ago (see Does Eating Obesity Cause Obesity?).

There are a number of cuts of beef that have less cholesterol-raising saturated fat than chicken (see BOLD Indeed: Beef Lowers Cholesterol?), so it's not so surprising that white meat was found to be no better than red, but the beef industry researchers conclusion was that "therefore you can eat beef as part of a balanced diet to manage your cholesterol."

Think of the Coke versus Pepsi analogy. Coke has less sugar than Pepsi: 15 spoonfuls of sugar per bottle instead of 16. If studies on blood sugar found no difference between drinking Coke versus Pepsi, you wouldn't conclude that "Pepsi may be considered when recommending diets for the management of blood sugars," you'd say they're both equally as bad so we should ideally consume neither.

That's a standard drug industry trick. You don't compare your fancy new drug to the best out there, but to some miserable drug to make yours look better. Note they didn't compare beef to plant proteins, like in this study published in the American Journal of Clinical Nutrition. As I started reading it, though, I was surprised that they found no benefit of switching to a plant protein diet either. What were they eating? You can see the comparison in Switching from Beef to Chicken & Fish May Not Lower Cholesterol.

For breakfast, the plant group got a kidney bean and tomato casserole and a salad, instead of a burger. And for dinner, instead of another burger, the plant protein group just got some boring vegetables. So why was the cholesterol of the plant group as bad as the animal group? They had the plant protein group eating three tablespoons of beef tallow every day--three tablespoons of straight beef fat!

This was part of a series of studies that tried to figure out what was so cholesterol-raising about meat--was it the animal protein or was it the animal fat? So, researchers created fake meat products made to have the same amount of saturated fat and cholesterol by adding extracted animal fats and cholesterol. Who could they get to make such strange concoctions? The Ralston Purina dog food company.

But what's crazy is that even when keeping the saturated animal fat and cholesterol the same (by adding meat fats to the veggie burgers and making the plant group swallow cholesterol pills to equal it out), sometimes they still saw a cholesterol lowering advantage in the plant protein group.

If you switch people from meat to tofu, their cholesterol goes down, but what if you switch them from meat to tofu plus lard? Then their cholesterol may stay the same, though tofu and lard may indeed actually be better than meat, since it may result in less oxidized cholesterol. More on the role of oxidized cholesterol can be found in my videos Does Cholesterol Size Matter? and Arterial Acne.

Just swapping plant protein for animal protein may have advantages, but if you really want to maximize the power of diet to lower cholesterol, you may have to move entirely toward plants. The standard dietary advice to cut down on fatty meat, dairy, and eggs may lower cholesterol 5-10%, but flexitarian or vegetarian diets may drop our levels 10 to 15%, vegan diets 15 to 25%, and healthier vegan diets can cut up to 35%, as seen in this study out of Canada showing a whopping 61 point drop in LDL cholesterol within a matter of weeks.


You thought chicken was a low-fat food? It used to be a century ago, but not anymore. It may even be one of the reasons we're getting fatter as well: Chicken Big: Poultry and Obesity and Infectobesity: Adenovirus 36 and Childhood Obesity.

Isn't protein just protein? How does our body know if it's coming from a plant or an animal? How could it have different effects on cardiovascular risk? See Protein and Heart Disease, another reason why Plant Protein [is] Preferable.

Lowering cholesterol in your blood is as simple as reducing one's intake of three things: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

What about those news stories on the "vindication" of saturated fat? See the sneaky science in The Saturated Fat Studies: Buttering Up the Public and The Saturated Fat Studies: Set Up to Fail.

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: CDC/Debora Cartagena via Freestockphotos.biz. This image has been modified.

Original Link

White Meat May Be as Cholesterol-Raising as Red

White Meat May Be as Cholesterol-Raising as Red.jpeg

In light of recommendations for heart healthy eating from national professional organizations encouraging Americans to limit their intake of meat, the beef industry commissioned and co-wrote a review of randomized controlled trials comparing the effects of beef versus chicken and fish on cholesterol levels published over the last 60 years. They found that the impact of beef consumption on the cholesterol profile of humans is similar to that of fish and/or poultry--meaning that switching from red meat to white meat likely wouldn't make any difference. And that's really no surprise, given how fat we've genetically manipulated chickens to be these days, up to ten times more fat than they had a century ago (see Does Eating Obesity Cause Obesity?).

There are a number of cuts of beef that have less cholesterol-raising saturated fat than chicken (see BOLD Indeed: Beef Lowers Cholesterol?), so it's not so surprising that white meat was found to be no better than red, but the beef industry researchers conclusion was that "therefore you can eat beef as part of a balanced diet to manage your cholesterol."

Think of the Coke versus Pepsi analogy. Coke has less sugar than Pepsi: 15 spoonfuls of sugar per bottle instead of 16. If studies on blood sugar found no difference between drinking Coke versus Pepsi, you wouldn't conclude that "Pepsi may be considered when recommending diets for the management of blood sugars," you'd say they're both equally as bad so we should ideally consume neither.

That's a standard drug industry trick. You don't compare your fancy new drug to the best out there, but to some miserable drug to make yours look better. Note they didn't compare beef to plant proteins, like in this study published in the American Journal of Clinical Nutrition. As I started reading it, though, I was surprised that they found no benefit of switching to a plant protein diet either. What were they eating? You can see the comparison in Switching from Beef to Chicken & Fish May Not Lower Cholesterol.

For breakfast, the plant group got a kidney bean and tomato casserole and a salad, instead of a burger. And for dinner, instead of another burger, the plant protein group just got some boring vegetables. So why was the cholesterol of the plant group as bad as the animal group? They had the plant protein group eating three tablespoons of beef tallow every day--three tablespoons of straight beef fat!

This was part of a series of studies that tried to figure out what was so cholesterol-raising about meat--was it the animal protein or was it the animal fat? So, researchers created fake meat products made to have the same amount of saturated fat and cholesterol by adding extracted animal fats and cholesterol. Who could they get to make such strange concoctions? The Ralston Purina dog food company.

But what's crazy is that even when keeping the saturated animal fat and cholesterol the same (by adding meat fats to the veggie burgers and making the plant group swallow cholesterol pills to equal it out), sometimes they still saw a cholesterol lowering advantage in the plant protein group.

If you switch people from meat to tofu, their cholesterol goes down, but what if you switch them from meat to tofu plus lard? Then their cholesterol may stay the same, though tofu and lard may indeed actually be better than meat, since it may result in less oxidized cholesterol. More on the role of oxidized cholesterol can be found in my videos Does Cholesterol Size Matter? and Arterial Acne.

Just swapping plant protein for animal protein may have advantages, but if you really want to maximize the power of diet to lower cholesterol, you may have to move entirely toward plants. The standard dietary advice to cut down on fatty meat, dairy, and eggs may lower cholesterol 5-10%, but flexitarian or vegetarian diets may drop our levels 10 to 15%, vegan diets 15 to 25%, and healthier vegan diets can cut up to 35%, as seen in this study out of Canada showing a whopping 61 point drop in LDL cholesterol within a matter of weeks.


You thought chicken was a low-fat food? It used to be a century ago, but not anymore. It may even be one of the reasons we're getting fatter as well: Chicken Big: Poultry and Obesity and Infectobesity: Adenovirus 36 and Childhood Obesity.

Isn't protein just protein? How does our body know if it's coming from a plant or an animal? How could it have different effects on cardiovascular risk? See Protein and Heart Disease, another reason why Plant Protein [is] Preferable.

Lowering cholesterol in your blood is as simple as reducing one's intake of three things: Trans Fat, Saturated Fat, and Cholesterol: Tolerable Upper Intake of Zero.

What about those news stories on the "vindication" of saturated fat? See the sneaky science in The Saturated Fat Studies: Buttering Up the Public and The Saturated Fat Studies: Set Up to Fail.

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: CDC/Debora Cartagena via Freestockphotos.biz. 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

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

Original Link

Do Dietary Toxins Contribute to Hand Tremors?

NF-Nov26 Essential Tremor and Diet.jpg

Essential tremor, affecting 1 in 25 adults over 40 and up to 1 in 5 of those in their 90s, is one of the most common neurological diseases. In addition to the potentially debilitating hand tremor, there can be other neuropsychiatric manifestations, including difficulty walking and various levels of cognitive impairment.

Might beta-carboline neurotoxins play a role in essential tremor? Harmane is one of the most potent of the tremor-producing neurotoxins. Expose people to harmane, and they develop tremors; take it away, and the tremors disappear. What if we're exposed long-term? A recent study at Columbia University, highlighted in my video, Essential Tremor and Diet, found that those with essential tremor have much higher levels of this toxin in their bloodstream compared to those without tremor. Furthermore, the higher the harmane levels, the worse the tremor. The highest levels are found in those who have both essential tremor and cancer, suggesting harmane may be playing a role in both diseases.

How did folks get exposed to these chemicals? Primarily through meat: beef, pork, fish, and especially chicken. So if this potent, tremor-producing neurotoxin is concentrated in cooked muscle foods, is meat consumption associated with a higher risk of essential tremor? Another Columbia University study found that men who ate the most meat had 21 times the odds of essential tremor. To put that in context, if we go back to the original studies on smoking and lung cancer, we see that smoking was only linked to about 14 times the odds, not 21.

Blood levels of this neurotoxin may shoot up within five minutes of eating meat. Five minutes? It's not even digested by then. This rapid uptake is indicative of significant absorption directly through the mouth straight into the bloodstream, bypassing the stomach and, most importantly, bypassing the detoxifying enzymes of the liver. This may lead to higher exposure levels in peripheral organs, like the brain.

Due to its high fat solubility, harmane accumulates in brain tissue, and, using a fancy brain scan called "proton magnetic resonance spectroscopic imaging," higher harmane levels have been linked to greater metabolic dysfunction in the brains of essential tremor sufferers.

Harmane is also found in certain heated plants, like tobacco. A broiled chicken breast has about 13 micrograms of harmane, and cigarettes average about one microgram, so a half pack of cigarettes could expose us to almost as much of this neurotoxin as a serving of chicken. Harman is created when tobacco is burned, and also when coffee beans are roasted. However, coffee intake has not been tied to increased risk (and neither has tobacco for that matter), so it may be something else in meat that's to blame for the 2,000 percent increase in odds for this disabling brain disease.

I also have a few videos about the other major tremor condition, Parkinson's Disease: Preventing Parkinson's Disease with Diet and Treating Parkinson's Disease with Diet

Other compounds created in cooked meats may also have implications for cancer risk:

-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: Gennaro D'Orio / Flickr

Original Link

Dr. Greger’s 2015 Live Year-in-Review Presentation

Food as Medicine

View my new live presentation here: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet

Every year I scour the world's scholarly literature on clinical nutrition, pulling together what I find to be the most interesting, practical, and groundbreaking science on how to best feed ourselves and our families. I start with the thousands of papers published annually on nutrition (27,000 this year--a new record!) and, thanks to a crack team of volunteers (and now staff!), I'm able to whittle those down (to a mere 8,000 this year). They are then downloaded, categorized, read, analyzed, and churned into the few hundred short videos. This allows me to post new videos and articles every day, year-round, to NutritionFacts.org. This certainly makes the site unique. There's no other science-based source for free daily updates on the latest discoveries in nutrition. The problem is that the amount of information can be overwhelming.

Currently I have more than a thousand videos covering 1,931 nutrition topics. Where do you even begin? Many have expressed their appreciation for the breadth of material, but asked that I try to distill it into a coherent summary of how best to use diet to prevent and treat chronic disease. I took this feedback to heart and in 2012 developed Uprooting the Leading Causes of Death, which explored the role diet may play in preventing, arresting, and even reversing our top 15 killers. Not only did it rise to become one of the Top 10 Most Popular Videos of 2012, it remains my single most viewed video to date, watched over a million times (NutritionFacts.org is now up to more than 1.5 million hits a month!).

In 2013 I developed the sequel, More Than an Apple a Day, in which I explored the role diet could play in treating some of our most common conditions. I presented it around the country and it ended up #1 on our Top 10 Most Popular Videos of 2013. Then in 2014 I premiered the sequel-sequel, From Table to Able, in which I explored the role diet could play in treating some of our most disabling diseases, landing #1 on our Top 10 Most Popular Videos of 2014.

Every year I wonder how I'm going to top the year before. Knowing how popular these live presentations can be and hearing all the stories from folks about what a powerful impact they can have on people's lives, I put my all into this new 2015 one. I spent more time putting together this presentation than any other in my life. It took me an entire month, and when you see it I think you'll appreciate why.

This year, I'm honored to bring you Food as Medicine, in which I go through our most dreaded diseases--but that's not even the best part! I'm really proud of what I put together for the ending. I spend the last 20 minutes or so (starting at 56:22) going through a thought experiment that I'm hoping everyone will find compelling. I think it may be my best presentation ever. You be the judge.

You can watch it at no cost online, but it is also available on DVD through my website or on Amazon. If you want to share copies with others, I have a five for $40 special (enter coupon code 5FOR40FAM). All proceeds from the sales of all my books, DVDs, downloads, and presentations go to the 501c3 nonprofit charity that keeps NutritionFacts.org free for all, for all time. If you want to support this initiative to educate millions about eradicating dietary diseases, please consider making a donation.

After you've watched the new presentation, make sure you're subscribed to get my video updates daily, weekly, or monthly to stay on top of all the latest.

-Michael Greger

Original Link