Treating Kidney Stones with Diet

Treating Kidney Stones with Diet.jpeg

Studies suggest that excessive consumption of animal protein poses a risk of kidney stone formation, likely due to the acid load contributed by the high content of sulfur-containing amino acids in animal protein, a topic I explore in my video, Preventing Kidney Stones with Diet. What about treating kidney stones, though? I discuss that in How to Treat Kidney Stones with Diet. Most stones are calcium oxalate, formed like rock candy when the urine becomes supersaturated. Doctors just assumed that if stones are made out of calcium, we simply have to tell people to reduce their calcium intake. That was the dietary gospel for kidney stone sufferers until a 2002 study published in the New England Journal of Medicine pitted two diets against one another--a low-calcium diet versus a diet low in animal protein and salt. The restriction of animal protein and salt provided greater protection, cutting the risk of having another kidney stone within five years in half.

What about cutting down on oxalates, which are concentrated in certain vegetables? A recent study found there was no increased risk of stone formation with higher vegetable intake. In fact, greater dietary intake of whole plant foods, fruits, and vegetables were each associated with reduced risk independent of other known risk factors for kidney stones. This means we may get additional benefits bulking up on plant foods in addition to just restricting animal foods.

A reduction in animal protein not only reduces the production of acids within the body, but should also limit the excretion of urate, uric acid crystals that can act as seeds to form calcium stones or create entire stones themselves. (Uric acid stones are the second most common kidney stones after calcium.)

There are two ways to reduce uric acid levels in the urine: a reduction of animal protein ingestion, or a variety of drugs. Removing all meat--that is, switching from the standard Western diet to a vegetarian diet--can remove 93% of uric acid crystallization risk within days.

To minimize uric acid crystallization, the goal is to get our urine pH up to ideally as high as 6.8. A number of alkalinizing chemicals have been developed for just this purpose, but we can naturally alkalize our urine up to the recommended 6.8 using purely dietary means. Namely, by removing all meat, someone eating the standard Western diet can go from a pH of 5.95 to the goal target of 6.8--simply by eating plant-based. As I describe in my video, Testing Your Diet with Pee & Purple Cabbage, we can inexpensively test our own diets with a little bathroom chemistry, for not all plant foods are alkalinizing and not all animal foods are equally acidifying.

A Load of Acid to Kidney Evaluation (LAKE) score has been developed to take into account both the acid load of foods and their typical serving sizes. It can be used to help people modify their diet for the prevention of both uric acid and calcium kidney stones, as well as other diseases. What did researchers find? The single most acid-producing food is fish, like tuna. Then, in descending order, are pork, then poultry, cheese (though milk and other dairy are much less acidifying), and beef followed by eggs. (Eggs are actually more acidic than beef, but people tend to eat fewer eggs in one sitting.) Some grains, like bread and rice, can be a little acid-forming, but pasta is not. Beans are significantly alkaline-forming, but not as much as fruits or even better, vegetables, which are the most alkaline-forming of all.

Through dietary changes alone, we may be able to dissolve uric acid stones completely and cure patients without drugs or surgery.

To summarize, the most important things we can do diet-wise is to drink 10 to 12 cups of water a day, reduce animal protein, reduce salt, and eat more vegetables and more vegetarian.

Want to try to calculate their LAKE score for the day? Just multiply the number of servings you have of each of the food groups listed in the graph in the video times the score.

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

Original Link

Can Oatmeal Reverse Heart Disease?

Can Oatmeal Reverse Heart Disease?.jpeg

Fiber continues to be singled out as a nutrient of public health concern. We're getting only about half the minimum recommended intake on average. There is a fiber gap in America. Less than 3 percent meet the recommended minimum. This means that less than 3 percent of all Americans eat enough whole plant foods, the only place fiber is found in abundance. If even half of the adult population ate 3 more grams a day--a quarter cup of beans or a bowl of oatmeal--we could potentially save billions in medical costs. And that's just for constipation! The consumption of plant foods, of fiber-containing foods, may reduce the risk for diabetes, heart disease, stroke, cancer, and obesity as well.

The first to make this link between fiber intake and killer disease was probably Dr. Hugh Trowell. He spent 30 years practicing medicine in Africa and suspected it was the Africans high consumption of corn, millet, sweet potatoes, greens, and beans that protected them from chronic disease. This twisted into the so-called "fiber hypothesis," but Trowell didn't think it was the fiber itself, but the high-fiber foods themselves that were protective. There are hundreds of different substances in whole plant foods besides fiber that may have beneficial effects. For example, the fiber in oatmeal can lower our blood cholesterol levels so that less gets stuck in our arteries, but there also are anti-inflammatory and antioxidant phytonutrients in oats that can prevent atherosclerotic build-up and then help maintain arterial function (see Can Oatmeal Reverse Heart Disease?).

Visionaries like Trowell were not entrapped by the reductionist "simple-minded" focus on dietary fiber and insisted that the whole plant foods should receive the emphasis. Fiber intake was just a marker for plant food intake. Those with the highest fiber intake and the lowest cholesterol were those whose who ate exclusively plant-based diets.

Risk factors like cholesterol are one thing, but can these individual foods actually affect the progression of heart disease, the #1 killer of Americans? We didn't know until 2005. Hundreds of older women were subjected to coronary angiograms, where we inject dye into the coronary arteries of the heart to see how wide open they are. Each participant got an angiogram at the beginning of the study and one a few years later, all while researchers analyzed their diets. The arteries of women eating less than a serving of whole grains a day significantly narrowed, whereas the arteries of women who ate just a single serving or more also significantly narrowed, but they narrowed less. These were all women with heart disease eating the standard American diet, so their arteries were progressively clogging shut. But there was significantly less clogging in the women eating more whole grains, significantly less progression of their atherosclerosis. A similar slowing of their disease might be expected from taking cholesterol-lowering statin drugs. But do we want to just slow the rate at which we die from heart disease, or do we want to not die from heart disease at all?

A strictly plant-based diet has been shown to reverse the progression of heart disease, opening up arteries back up. Yes, whole grains, like drugs, can help counter the artery-clogging effects of the rest of the diet. Having oatmeal with bacon and eggs is better than just eating bacon and eggs, but why not stop eating an artery-clogging diet altogether?

Oatmeal offers a lot more than fiber, though. See Oatmeal Lotion for Chemotherapy-Induced Rash and Can Oatmeal Help Fatty Liver Disease?

Trowell's work had a big influence on Dr. Denis Burkitt. See Dr. Burkitt's F-Word Diet.

This reminds me of other interventions like hibiscus tea for high blood pressure (Hibiscus Tea vs. Plant-Based Diets for Hypertension) or amla for diabetes (Amla Versus Diabetes). Better to reverse the disease completely.

And for an overview of how whole plant foods affect disease risks, be sure to check out the videos on our new Introduction page!

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: Rachel Hathaway / Flickr. This image has been modified.

Original Link

Can Oatmeal Reverse Heart Disease?

Can Oatmeal Reverse Heart Disease?.jpeg

Fiber continues to be singled out as a nutrient of public health concern. We're getting only about half the minimum recommended intake on average. There is a fiber gap in America. Less than 3 percent meet the recommended minimum. This means that less than 3 percent of all Americans eat enough whole plant foods, the only place fiber is found in abundance. If even half of the adult population ate 3 more grams a day--a quarter cup of beans or a bowl of oatmeal--we could potentially save billions in medical costs. And that's just for constipation! The consumption of plant foods, of fiber-containing foods, may reduce the risk for diabetes, heart disease, stroke, cancer, and obesity as well.

The first to make this link between fiber intake and killer disease was probably Dr. Hugh Trowell. He spent 30 years practicing medicine in Africa and suspected it was the Africans high consumption of corn, millet, sweet potatoes, greens, and beans that protected them from chronic disease. This twisted into the so-called "fiber hypothesis," but Trowell didn't think it was the fiber itself, but the high-fiber foods themselves that were protective. There are hundreds of different substances in whole plant foods besides fiber that may have beneficial effects. For example, the fiber in oatmeal can lower our blood cholesterol levels so that less gets stuck in our arteries, but there also are anti-inflammatory and antioxidant phytonutrients in oats that can prevent atherosclerotic build-up and then help maintain arterial function (see Can Oatmeal Reverse Heart Disease?).

Visionaries like Trowell were not entrapped by the reductionist "simple-minded" focus on dietary fiber and insisted that the whole plant foods should receive the emphasis. Fiber intake was just a marker for plant food intake. Those with the highest fiber intake and the lowest cholesterol were those whose who ate exclusively plant-based diets.

Risk factors like cholesterol are one thing, but can these individual foods actually affect the progression of heart disease, the #1 killer of Americans? We didn't know until 2005. Hundreds of older women were subjected to coronary angiograms, where we inject dye into the coronary arteries of the heart to see how wide open they are. Each participant got an angiogram at the beginning of the study and one a few years later, all while researchers analyzed their diets. The arteries of women eating less than a serving of whole grains a day significantly narrowed, whereas the arteries of women who ate just a single serving or more also significantly narrowed, but they narrowed less. These were all women with heart disease eating the standard American diet, so their arteries were progressively clogging shut. But there was significantly less clogging in the women eating more whole grains, significantly less progression of their atherosclerosis. A similar slowing of their disease might be expected from taking cholesterol-lowering statin drugs. But do we want to just slow the rate at which we die from heart disease, or do we want to not die from heart disease at all?

A strictly plant-based diet has been shown to reverse the progression of heart disease, opening up arteries back up. Yes, whole grains, like drugs, can help counter the artery-clogging effects of the rest of the diet. Having oatmeal with bacon and eggs is better than just eating bacon and eggs, but why not stop eating an artery-clogging diet altogether?

Oatmeal offers a lot more than fiber, though. See Oatmeal Lotion for Chemotherapy-Induced Rash and Can Oatmeal Help Fatty Liver Disease?

Trowell's work had a big influence on Dr. Denis Burkitt. See Dr. Burkitt's F-Word Diet.

This reminds me of other interventions like hibiscus tea for high blood pressure (Hibiscus Tea vs. Plant-Based Diets for Hypertension) or amla for diabetes (Amla Versus Diabetes). Better to reverse the disease completely.

And for an overview of how whole plant foods affect disease risks, be sure to check out the videos on our new Introduction page!

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: Rachel Hathaway / Flickr. This image has been modified.

Original Link

Best Foods for Acid Reflux

Best Foods for Acid Reflux.jpeg

Gastroesophageal reflux disease (GERD) is one of the most common disorders of the digestive tract. The two most typical symptoms are heartburn and regurgitation of stomach contents into the back of the throat, but GERD is not just burning pain and a sour taste in your mouth. It causes millions of doctor visits and hospitalizations every year in the United States. The most feared complication is cancer.

You start out with a normal esophagus. If the acid keeps creeping up, your esophagus can get inflamed and result in esophagitis. Esophagitis can transform into Barrett's esophagus, a precancerous condition which can then turn into adenocarcinoma (a type of cancer). To prevent all that, we need to prevent the acid reflux in the first place.

In the last three decades, the incidence of this cancer in the US has increased six-fold, an increase greater than that of melanoma, breast, or prostate cancer. This is because acid reflux is on the rise. In the United States, we're up to about 1 in 4 people suffering at least weekly heartburn and/or acid regurgitation, compared to around 5% in Asia. This suggests that dietary factors may play a role.

In general, high fat intake is associated with increased risk, whereas high fiber foods appear to be protective. The reason fat intake may be associated with GERD symptoms and erosive esophagitis is because when we eat fatty foods, the sphincter at the top of the stomach that's supposed to keep the food down becomes relaxed, so more acid can creep up into the esophagus. In my video Diet & GERD Acid Reflux Heartburn, you can see a study in which researchers fed volunteers a high-fat meal--a McDonald's sausage and egg McMuffin--compared to a low-fat meal (McDonald's hot cakes), and there was significantly more acid squirted up in the esophagus after the high-fat meal.

In terms of later stages of disease progression, over the last twenty years 45 studies have been published in the association between diet and Barrett's esophagus and esophageal cancer. In general, they found that meat and high-fat meals appeared to increase cancer risk. Different meats were associated with cancers in different locations, thoughj. Red meat was more associated with cancer in the esophagus, whereas poultry was more associated with cancer at the top of the stomach. Plant-based sources of protein, such as beans and nuts, were associated with a significantly decreased risk of cancer.

Those eating the most antioxidant-rich foods have half the odds of esophageal cancer, while there is practically no reduction in risk among those who used antioxidant vitamin supplements, such as vitamin C or E pills. The most protective produce may be red-orange vegetables, dark green leafies, berries, apples, and citrus. The benefit may come from more than just eating plants. Eating healthy foods crowds out less healthy foods, so it may be a combination of both.

Based on a study of 3,000 people, the consumption of non-vegetarian foods (including eggs) was an independent predictor of GERD. Egg yolks cause an increase in the hormone cholecystokinin, which may overly relax the sphincter that separates the esophagus from the stomach. The same hormone is increased by meat, which may help explain why plant-based diets appear to be a protective factor for reflux esophagitis.

Researchers found that those eating meat had twice the odds of reflux-induced esophageal inflammation. Therefore, plant-based diets may offer protection, though it's uncertain whether it's attributable to the absence of meat in the diet or the increased consumption of healthy foods. Those eating vegetarian consume greater amounts of fruits and vegetables containing innumerable phytochemicals, dietary fiber, and antioxidants. They also restrict their consumption of animal sources of food, which tend to be fattier and can thus relax that sphincter and aggravate reflux.

GERD is common; its burdens are enormous. It relapses frequently and can cause bleeding, strictures, and a deadly cancer. The mainstay of treatment is proton pump inhibitor drugs, which rake in billions of dollars. We spend four billion dollars on Nexium alone, three billion on Prevacid, two billion on Protonix, one billion on Aciphex. These drugs can cause nutrient deficiencies and increase the risk for pneumonia, food poisoning, and bone fractures. Thus, it is important to find correctable risk factors and correct them. Known correctable risk factors have been things like obesity, smoking and alcohol consumption. Until recently, though, there hadn't been studies on specifically what to eat and what to avoid, but now we have other correctable factors to help prevent this disease.

For more on GERD, see: Diet & Hiatal Hernia, Coffee & Mortality, and Club Soda for Stomach Pain & Constipation.

I also have a video about esophageal cancer, detailing the extraordinary reversal of the kinds of precancerous changes that lead to the devastating condition--with nothing but strawberries: Strawberries versus Esophageal Cancer.

In health,

Michael Greger, M.D.

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

Image Credit: PDPics / Pixabay. Image has been modified.

Original Link

Best Foods for Acid Reflux

Best Foods for Acid Reflux.jpeg

Gastroesophageal reflux disease (GERD) is one of the most common disorders of the digestive tract. The two most typical symptoms are heartburn and regurgitation of stomach contents into the back of the throat, but GERD is not just burning pain and a sour taste in your mouth. It causes millions of doctor visits and hospitalizations every year in the United States. The most feared complication is cancer.

You start out with a normal esophagus. If the acid keeps creeping up, your esophagus can get inflamed and result in esophagitis. Esophagitis can transform into Barrett's esophagus, a precancerous condition which can then turn into adenocarcinoma (a type of cancer). To prevent all that, we need to prevent the acid reflux in the first place.

In the last three decades, the incidence of this cancer in the US has increased six-fold, an increase greater than that of melanoma, breast, or prostate cancer. This is because acid reflux is on the rise. In the United States, we're up to about 1 in 4 people suffering at least weekly heartburn and/or acid regurgitation, compared to around 5% in Asia. This suggests that dietary factors may play a role.

In general, high fat intake is associated with increased risk, whereas high fiber foods appear to be protective. The reason fat intake may be associated with GERD symptoms and erosive esophagitis is because when we eat fatty foods, the sphincter at the top of the stomach that's supposed to keep the food down becomes relaxed, so more acid can creep up into the esophagus. In my video Diet & GERD Acid Reflux Heartburn, you can see a study in which researchers fed volunteers a high-fat meal--a McDonald's sausage and egg McMuffin--compared to a low-fat meal (McDonald's hot cakes), and there was significantly more acid squirted up in the esophagus after the high-fat meal.

In terms of later stages of disease progression, over the last twenty years 45 studies have been published in the association between diet and Barrett's esophagus and esophageal cancer. In general, they found that meat and high-fat meals appeared to increase cancer risk. Different meats were associated with cancers in different locations, thoughj. Red meat was more associated with cancer in the esophagus, whereas poultry was more associated with cancer at the top of the stomach. Plant-based sources of protein, such as beans and nuts, were associated with a significantly decreased risk of cancer.

Those eating the most antioxidant-rich foods have half the odds of esophageal cancer, while there is practically no reduction in risk among those who used antioxidant vitamin supplements, such as vitamin C or E pills. The most protective produce may be red-orange vegetables, dark green leafies, berries, apples, and citrus. The benefit may come from more than just eating plants. Eating healthy foods crowds out less healthy foods, so it may be a combination of both.

Based on a study of 3,000 people, the consumption of non-vegetarian foods (including eggs) was an independent predictor of GERD. Egg yolks cause an increase in the hormone cholecystokinin, which may overly relax the sphincter that separates the esophagus from the stomach. The same hormone is increased by meat, which may help explain why plant-based diets appear to be a protective factor for reflux esophagitis.

Researchers found that those eating meat had twice the odds of reflux-induced esophageal inflammation. Therefore, plant-based diets may offer protection, though it's uncertain whether it's attributable to the absence of meat in the diet or the increased consumption of healthy foods. Those eating vegetarian consume greater amounts of fruits and vegetables containing innumerable phytochemicals, dietary fiber, and antioxidants. They also restrict their consumption of animal sources of food, which tend to be fattier and can thus relax that sphincter and aggravate reflux.

GERD is common; its burdens are enormous. It relapses frequently and can cause bleeding, strictures, and a deadly cancer. The mainstay of treatment is proton pump inhibitor drugs, which rake in billions of dollars. We spend four billion dollars on Nexium alone, three billion on Prevacid, two billion on Protonix, one billion on Aciphex. These drugs can cause nutrient deficiencies and increase the risk for pneumonia, food poisoning, and bone fractures. Thus, it is important to find correctable risk factors and correct them. Known correctable risk factors have been things like obesity, smoking and alcohol consumption. Until recently, though, there hadn't been studies on specifically what to eat and what to avoid, but now we have other correctable factors to help prevent this disease.

For more on GERD, see: Diet & Hiatal Hernia, Coffee & Mortality, and Club Soda for Stomach Pain & Constipation.

I also have a video about esophageal cancer, detailing the extraordinary reversal of the kinds of precancerous changes that lead to the devastating condition--with nothing but strawberries: Strawberries versus Esophageal Cancer.

In health,

Michael Greger, M.D.

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

Image Credit: PDPics / Pixabay. Image has been modified.

Original Link

The Best Diet for Rheumatoid Arthritis

The Best Diet for Rheumatoid Arthritis.jpeg

Rheumatoid arthritis is a chronic systemic autoimmune disease affecting millions. It is characterized by persistent pain, stiffness, and progressive joint destruction leading to crippling deformities, particularly in the hands and feet. What can we do to prevent and treat it?

In my video Why Do Plant-Based Diets Help Rheumatoid Arthritis?, I show a famous 13-month randomized controlled trial of plant-based diets for rheumatoid arthritis where patients were put on a vegan diet for three and a half months and then switched to an egg-free lactovegetarian diet for the remainder of the study. Compared to the control group (who didn't change their diet at all), the plant-based group experienced significant improvements starting within weeks. Their morning stiffness improved within the first month, cutting the number of hours they suffered from joint stiffness in half. Their pain level dropped from 5 out of 10 down to less than 3 out of 10. Disability levels dropped, and subjects reported feeling better; they had greater grip strength, fewer tender joints, less tenderness per joint, and less swelling. They also had a drop in inflammatory markers in their blood, such as sedimentation rate, C-reactive protein, and white blood cell count. As a bonus, they lost about 13 pounds and kept most of that weight off throughout the year.

What does diet have to do with joint disease?

Rheumatoid arthritis is an autoimmune disease, in which our own body attacks the lining of our joints. There's also a different autoimmune disease called rheumatic fever, in which our body attacks our heart. Why would it do that? It appears to be a matter of friendly fire.

Rheumatic fever is caused by strep throat, which is itself caused by a bacterium that has a protein that looks an awful lot like a protein in our heart. When our immune system attacks the strep bacteria, it also attacks our heart valves, triggering an autoimmune attack by "molecular mimicry." The protein on the strep bacteria is mimicking a protein in our heart, so our body gets confused and attacks both. That's why it's critical to treat strep throat early to prevent our heart from getting caught in the crossfire.

Researchers figured that rheumatoid arthritis might be triggered by an infection as well. A clue to where to start looking was the fact that women seem to get it three times more frequently than men. What type of infection do women get more than men? Urinary tract infections (UTIs). So researchers started testing the urine of rheumatoid arthritis sufferers and, lo and behold, found a bacterium called Proteus mirabilis. Not enough to cause symptoms of a UTI, but enough to trigger an immune response. And indeed, there's a molecule in the bacterium that looks an awful lot like one of the molecules in our joints.

The theory is that anti-Proteus antibodies against the bacterial molecule may inadvertently damage our own joint tissues, leading eventually to joint destruction. Therefore, interventions to remove this bacteria from the bodies of patients, with consequent reduction of antibodies against the organism, should lead to a decrease in inflammation.

As we saw in my video Avoiding Chicken to Avoid Bladder Infections, urinary tract infections originate from the fecal flora. The bacteria crawl up from the rectum into the bladder. How might we change the bugs in our colons? By changing our diet.

Some of the first studies published more than 20 years ago to fundamentally shift people's gut flora were done using raw vegan diets, figuring that's about as fundamental a shift from the standard Western diet as possible. Indeed, within days researchers could significantly change subjects' gut flora. When researchers put rheumatoid arthritis sufferers on that kind of diet, they experienced relief, and the greatest improvements were linked to greatest changes in gut flora. The diet was considered so intolerable, though, that half the patients couldn't take it and dropped out, perhaps because they were trying to feed people things like "buckwheat-beetroot cutlets" buttered with a spread made out of almonds and fermented cucumber juice.

Thankfully, regular vegetarian and vegan diets work too, changing the intestinal flora and improving rheumatoid arthritis. However, we didn't specifically have confirmation that plant-based diets brought down anti-Proteus antibodies until 2014. Subjects that responded to the plant-based diet showed a significant drop in anti-Proteus mirabilis antibodies compared to the control group. Maybe it just dropped immune responses across the board? No, antibody levels against other bugs remained the same, so the assumption is that the plant-based diet reduced urinary or gut levels of the bacteria.

A shift from an omnivorous to a vegetarian diet has a profound influence on the composition of urine as well. For example, those eating plant-based had higher levels of lignans in their urine. Up until now, it was thought that they only protected people from getting cancer, but we now know lignans can also have antimicrobial properties. Perhaps they help clear Proteus mirabilis from the system. Either way, these data suggest a new type of therapy for the management of rheumatoid arthritis: anti-Proteus measures including plant-based diets.


I have to admit I had never even heard of Proteus mirabilis. That's why I love doing work--I learn as much as you do!

I explored another unconventional theory as to why plant-based diets are so successful in treating inflammatory arthritis in Potassium and Autoimmune Disease.

There's another foodborne bacteria implicated in human disease, the EXPEC in chicken leading to urinary tract infections--another game-changer: Avoiding Chicken To Avoid Bladder Infections.

I have a bunch of videos on gut flora--the microbiome. They include:

In health,

Michael Greger, M.D.

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

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

Original Link

The Best Diet for Rheumatoid Arthritis

The Best Diet for Rheumatoid Arthritis.jpeg

Rheumatoid arthritis is a chronic systemic autoimmune disease affecting millions. It is characterized by persistent pain, stiffness, and progressive joint destruction leading to crippling deformities, particularly in the hands and feet. What can we do to prevent and treat it?

In my video Why Do Plant-Based Diets Help Rheumatoid Arthritis?, I show a famous 13-month randomized controlled trial of plant-based diets for rheumatoid arthritis where patients were put on a vegan diet for three and a half months and then switched to an egg-free lactovegetarian diet for the remainder of the study. Compared to the control group (who didn't change their diet at all), the plant-based group experienced significant improvements starting within weeks. Their morning stiffness improved within the first month, cutting the number of hours they suffered from joint stiffness in half. Their pain level dropped from 5 out of 10 down to less than 3 out of 10. Disability levels dropped, and subjects reported feeling better; they had greater grip strength, fewer tender joints, less tenderness per joint, and less swelling. They also had a drop in inflammatory markers in their blood, such as sedimentation rate, C-reactive protein, and white blood cell count. As a bonus, they lost about 13 pounds and kept most of that weight off throughout the year.

What does diet have to do with joint disease?

Rheumatoid arthritis is an autoimmune disease, in which our own body attacks the lining of our joints. There's also a different autoimmune disease called rheumatic fever, in which our body attacks our heart. Why would it do that? It appears to be a matter of friendly fire.

Rheumatic fever is caused by strep throat, which is itself caused by a bacterium that has a protein that looks an awful lot like a protein in our heart. When our immune system attacks the strep bacteria, it also attacks our heart valves, triggering an autoimmune attack by "molecular mimicry." The protein on the strep bacteria is mimicking a protein in our heart, so our body gets confused and attacks both. That's why it's critical to treat strep throat early to prevent our heart from getting caught in the crossfire.

Researchers figured that rheumatoid arthritis might be triggered by an infection as well. A clue to where to start looking was the fact that women seem to get it three times more frequently than men. What type of infection do women get more than men? Urinary tract infections (UTIs). So researchers started testing the urine of rheumatoid arthritis sufferers and, lo and behold, found a bacterium called Proteus mirabilis. Not enough to cause symptoms of a UTI, but enough to trigger an immune response. And indeed, there's a molecule in the bacterium that looks an awful lot like one of the molecules in our joints.

The theory is that anti-Proteus antibodies against the bacterial molecule may inadvertently damage our own joint tissues, leading eventually to joint destruction. Therefore, interventions to remove this bacteria from the bodies of patients, with consequent reduction of antibodies against the organism, should lead to a decrease in inflammation.

As we saw in my video Avoiding Chicken to Avoid Bladder Infections, urinary tract infections originate from the fecal flora. The bacteria crawl up from the rectum into the bladder. How might we change the bugs in our colons? By changing our diet.

Some of the first studies published more than 20 years ago to fundamentally shift people's gut flora were done using raw vegan diets, figuring that's about as fundamental a shift from the standard Western diet as possible. Indeed, within days researchers could significantly change subjects' gut flora. When researchers put rheumatoid arthritis sufferers on that kind of diet, they experienced relief, and the greatest improvements were linked to greatest changes in gut flora. The diet was considered so intolerable, though, that half the patients couldn't take it and dropped out, perhaps because they were trying to feed people things like "buckwheat-beetroot cutlets" buttered with a spread made out of almonds and fermented cucumber juice.

Thankfully, regular vegetarian and vegan diets work too, changing the intestinal flora and improving rheumatoid arthritis. However, we didn't specifically have confirmation that plant-based diets brought down anti-Proteus antibodies until 2014. Subjects that responded to the plant-based diet showed a significant drop in anti-Proteus mirabilis antibodies compared to the control group. Maybe it just dropped immune responses across the board? No, antibody levels against other bugs remained the same, so the assumption is that the plant-based diet reduced urinary or gut levels of the bacteria.

A shift from an omnivorous to a vegetarian diet has a profound influence on the composition of urine as well. For example, those eating plant-based had higher levels of lignans in their urine. Up until now, it was thought that they only protected people from getting cancer, but we now know lignans can also have antimicrobial properties. Perhaps they help clear Proteus mirabilis from the system. Either way, these data suggest a new type of therapy for the management of rheumatoid arthritis: anti-Proteus measures including plant-based diets.


I have to admit I had never even heard of Proteus mirabilis. That's why I love doing work--I learn as much as you do!

I explored another unconventional theory as to why plant-based diets are so successful in treating inflammatory arthritis in Potassium and Autoimmune Disease.

There's another foodborne bacteria implicated in human disease, the EXPEC in chicken leading to urinary tract infections--another game-changer: Avoiding Chicken To Avoid Bladder Infections.

I have a bunch of videos on gut flora--the microbiome. They include:

In health,

Michael Greger, M.D.

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

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

Original Link

The Best Diet to Prevent Kidney Stones

The Best Diet to Prevent Kidney Stones.jpeg

In my video How to Prevent Kidney Stones With Diet you can see what the jagged surface of a kidney stone looks like under a microscope. Imagine one of those scraping down your urinary canal! Kidney stones affect approximately 1 in 11 people in the United States. Twenty years ago it was only 1 in 20, representing a dramatic increase in the prevalence of the disease that started rising after World War II. Our first clue as to why was a study published in the 70's, which found a striking relationship between stone incidence and the consumption of animal protein. This was a population study, though, so it couldn't prove cause and effect.

That study inspired researchers in Britain to do an interventional study, adding animal protein to subjects' diets, such as an extra can of tuna fish a day, and measuring stone-forming risk factors in their urine. Participants' overall probability of forming stones increased 250% during those days they were eating that extra fish. And the so-called "high animal protein diet" was just enough to bring intake up to that of the average American. So Americans' intake of meat appears to markedly increase the risk of kidney stones.

What about consuming no meat at all? By the late 70's we knew that the only dietary factor consistently associated with kidney stones was animal protein. The higher the intake of animal protein, the more likely the individual was to not only get their first kidney stone, but to then suffer from subsequent multiple stones. This effect was not found for high protein intake in general, but specifically high animal protein intake. Conversely, a diet low in animal protein may dramatically reduce the overall probability of forming stones. This may explain the apparently low incidence of stones in vegetarian societies, so researchers advocated "a more vegetarian form of diet" as a means of reducing the risk.

It wasn't until 2014 that vegetarian kidney stone risk was studied in detail, though. Using hospital admissions data, researchers found that vegetarians were indeed at a lower risk of being hospitalized for kidney stones. It's not all or nothing, though. Among meat-eaters, increasing meat intake is associated with a higher risk of developing kidney stones, whereas a high intake of fresh fruit, fiber, and magnesium may reduce the risk.

Which animal protein is the worst? People who form kidney stones are commonly advised to restrict the intake of red meat to decrease stone risk, but what about chicken and fish? Despite compelling evidence that excessive animal protein consumption enhances the risk of stone formation, the effect of different sources of animal protein had not been explored until another study in 2014. Researchers compared the effects of salmon and cod, chicken breast meat, and burger and steak. In terms of uric acid production, they found that gram for gram fish may actually be worse. However, the overall effects were complex. Basically, stone formers should be counseled to limit the intake of all animal proteins, and not by just a little bit. Only those who markedly decrease their animal protein intake may expect to benefit.

Making our urine more alkaline can also help prevent the formation of kidney stones (and even dissolve and cure uric acid stones). How can you tell the pH of your urine? See my video Testing Your Diet with Pee & Purple Cabbage.

For more on kidney stones, see How to Treat Kidney Stones with Diet and Do Vitamin C Supplements Prevent Colds but Cause Kidney Stones?. And check out my overview of kidney health in How Not to Die from Kidney Disease.

Uric acid can also crystallize in our joints, but the good news is that there are natural treatments. See Gout Treatment with a Cherry on Top and Treating Gout with Cherry Juice.

Kidney stones are just one more reason that Plant Protein is Preferable.

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.

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The Best Diet to Prevent Kidney Stones

The Best Diet to Prevent Kidney Stones.jpeg

In my video How to Prevent Kidney Stones With Diet you can see what the jagged surface of a kidney stone looks like under a microscope. Imagine one of those scraping down your urinary canal! Kidney stones affect approximately 1 in 11 people in the United States. Twenty years ago it was only 1 in 20, representing a dramatic increase in the prevalence of the disease that started rising after World War II. Our first clue as to why was a study published in the 70's, which found a striking relationship between stone incidence and the consumption of animal protein. This was a population study, though, so it couldn't prove cause and effect.

That study inspired researchers in Britain to do an interventional study, adding animal protein to subjects' diets, such as an extra can of tuna fish a day, and measuring stone-forming risk factors in their urine. Participants' overall probability of forming stones increased 250% during those days they were eating that extra fish. And the so-called "high animal protein diet" was just enough to bring intake up to that of the average American. So Americans' intake of meat appears to markedly increase the risk of kidney stones.

What about consuming no meat at all? By the late 70's we knew that the only dietary factor consistently associated with kidney stones was animal protein. The higher the intake of animal protein, the more likely the individual was to not only get their first kidney stone, but to then suffer from subsequent multiple stones. This effect was not found for high protein intake in general, but specifically high animal protein intake. Conversely, a diet low in animal protein may dramatically reduce the overall probability of forming stones. This may explain the apparently low incidence of stones in vegetarian societies, so researchers advocated "a more vegetarian form of diet" as a means of reducing the risk.

It wasn't until 2014 that vegetarian kidney stone risk was studied in detail, though. Using hospital admissions data, researchers found that vegetarians were indeed at a lower risk of being hospitalized for kidney stones. It's not all or nothing, though. Among meat-eaters, increasing meat intake is associated with a higher risk of developing kidney stones, whereas a high intake of fresh fruit, fiber, and magnesium may reduce the risk.

Which animal protein is the worst? People who form kidney stones are commonly advised to restrict the intake of red meat to decrease stone risk, but what about chicken and fish? Despite compelling evidence that excessive animal protein consumption enhances the risk of stone formation, the effect of different sources of animal protein had not been explored until another study in 2014. Researchers compared the effects of salmon and cod, chicken breast meat, and burger and steak. In terms of uric acid production, they found that gram for gram fish may actually be worse. However, the overall effects were complex. Basically, stone formers should be counseled to limit the intake of all animal proteins, and not by just a little bit. Only those who markedly decrease their animal protein intake may expect to benefit.

Making our urine more alkaline can also help prevent the formation of kidney stones (and even dissolve and cure uric acid stones). How can you tell the pH of your urine? See my video Testing Your Diet with Pee & Purple Cabbage.

For more on kidney stones, see How to Treat Kidney Stones with Diet and Do Vitamin C Supplements Prevent Colds but Cause Kidney Stones?. And check out my overview of kidney health in How Not to Die from Kidney Disease.

Uric acid can also crystallize in our joints, but the good news is that there are natural treatments. See Gout Treatment with a Cherry on Top and Treating Gout with Cherry Juice.

Kidney stones are just one more reason that Plant Protein is Preferable.

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.

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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.

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