How Much Water Should We Drink Every Day?

How Much Water Should We Drink Every Day?.jpeg

More than 2000 years ago Hippocrates (460-377 BCE) said, "If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health." What does that mean when it comes to water? Water has been described as a neglected, unappreciated, and under-researched subject, and further complicating the issue, a lot of the papers extolling the need for proper hydration are funded by the bottled water industry.

It turns out the often quoted "drink at least eight glasses of water a day" dictum has little underpinning scientific evidence . Where did that idea come from? The recommendation was traced to a 1921 paper, in which the author measured his own pee and sweat and determined we lose about 3% of our body weight in water a day, or about 8 cups (see How Many Glasses of Water Should We Drink in a Day?). Consequently, for the longest time, water requirement guidelines for humanity were based on just one person.

There is evidence that not drinking enough may be associated with falls and fractures, heat stroke, heart disease, lung disorders, kidney disease, kidney stones, bladder and colon cancer, urinary tract infections, constipation, dry mouth, cavities, decreased immune function and cataract formation. The problem with many of these studies is that low water intake is associated with several unhealthy behaviors, such as low fruit and vegetable intake, more fast-food, less shopping at farmers markets. And who drinks lots of water? People who exercise a lot. No wonder they tend to have lower disease rates!

Only large and expensive randomized trials could settle these questions definitively. Given that water cannot be patented, such trials seem unlikely; who's going to pay for them? We're left with studies that find an association between disease and low water intake. But are people sick because they drink less, or are they drinking less because they're sick? There have been a few large prospective studies in which fluid intake is measured before disease develops. For example, a Harvard study of 48,000 men found that the risk of bladder cancer decreased by 7% for every extra daily cup of fluid we drink. Therefore, a high intake of water--like 8 cups a day--may reduce the risk of bladder cancer by about 50%, potentially saving thousands of lives.

The accompanying editorial commented that strategies to prevent the most prevalent cancers in the West are remarkably straightforward in principle. To prevent lung cancer, quit smoking; to prevent breast cancer, maintain your ideal body weight and exercise; and to prevent skin cancer, stay out of the sun. Now comes this seemingly simple way to reduce the risk of bladder cancer: drink more fluids.

Probably the best evidence we have for a cut off of water intake comes from the Adventist Health Study, in which 20,000 men and women were studied. About one-half were vegetarian, so they were also getting extra water by eating more fruits and vegetables. Those drinking 5 or more glasses of water a day had about half the risk of dying from heart disease compared to those who drank 2 or fewer glasses a day. Like the Harvard study, this protection was found after controlling for other factors such as diet and exercise. These data suggest that it was the water itself that was decreasing risk, perhaps by lowering blood viscosity (blood thickness).

Based on all the best evidence to date, authorities from Europe, the U.S. Institute of Medicine, and the World Health Organization recommend between 2.0 and 2.7 liters (8 to 11 cups) of water a day for women, and 2.5 to 3.7 liters (10 to 15 cups) a day for men. This includes water from all sources, not just beverages. We get about a liter from food and the water our body makes. So this translates into a recommendation for women to drink 4 to 7 cups of water a day and men 6 to 11 cups, assuming only moderate physical activity at moderate ambient temperatures.

We can also get water from all the other drinks we consume, including caffeinated drinks, with the exception of stronger alcoholic drinks like wines and spirits. Beer can leave you with more water than you started with, but wine actively dehydrates you. However, in the cancer and heart disease studies I mentioned above, the benefits were only found with increased water consumption, not other beverages.

I've previously touched on the cognitive benefits of proper hydration here: Does a Drink Of Water Make Children Smarter?

Surprised tea is hydrating? See my video Is Caffeinated Tea Dehydrating?

Surprised that the 8-a-day rested on such flimsy evidence? Unfortunately, so much of what we do in medicine has shaky underpinnings. That's the impetus behind the idea of evidence-based medicine (what a concept!). Ironically, this new movement may itself undermine some of the most effective treatments. See Evidence-Based Medicine or Evidence-Biased?

How else can we reduce our risk of bladder cancer? See Raw Broccoli and Bladder Cancer Survival.

What kind of water? I recommend tap water, which tends to be preferable from a chemical and microbial contamination standpoint. What about buying one of those fancy alkalizing machines? See Alkaline Water: a Scam?

It's so nice to have data on such a fundamental question. We have much to thank the Adventists for. You will see their studies cropping up frequently. See, for example, Plant-Based Diets and Diabetes, The Okinawa Diet: Living to 100, and Evidence-Based Eating.

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. 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

Foods that Affect Testosterone Levels

Foods that Affect Testosterone Levels.jpeg

A number of studies suggest that exposure to industrial pollutants may affect sexual function, for example, loss of libido, sexual dysfunction, and impotence. This may be due to effects on testosterone levels. In a study of men who ate a lot of contaminated fish, an elevation in PCB levels in the blood was associated with a lower concentration of testosterone levels. These pollutants are found predominantly in fish, but also meat and dairy. The lowest levels are found in plants (see Dietary Pollutants May Affect Testosterone Levels).

Testosterone doesn't just play a role in the determination of secondary sex characteristics like facial hair at puberty. It also regulates normal sexual functioning and the overall physical and psychological well-being of adult men. Abnormally low levels of testosterone can lead to decreased physical endurance and memory capacity, loss of libido, drop in sperm count, loss of bone density, obesity, and depression.

Endocrine-disrupting compounds that build up in fish may be able to mimic or block hormone receptors, or alter rates of synthesis or breakdown of sex steroid hormones. In children, these pollutants may actually impair sexual development. Boys who are exposed may grow up with smaller penises (although only by about two-thirds of an inch shorter at most). Researchers have tried exposing cells from aborted fetal human penises to these kinds of dietary pollutants, and gene expression related to genital development is indeed affected at real-life exposure levels. We're not sure if the effects on penis length are due to the pro-estrogenic effects of the toxins, though, or the anti-testosterone effects.

You've heard of save the whales? Well, male reproductive organs may be at risk from environmental hazards as well.

I previously addressed how we discovered the endocrine disruptor phenomenon in Alkylphenol Endocrine Disruptors and Allergies, as well as where they're found (Dietary Sources of Alkylphenol Endocrine Disruptors).

For more on sustaining male virility, see Male Fertility and Diet, The Role of Diet in Declining Sperm Counts, and Dairy Estrogen and Male Fertility.

I've talked about the role a plastics chemical may play in male sexual functioning (BPA Plastic and Male Sexual Dysfunction). But it's not just toxins, it's the total diet (Survival of the Firmest: Erectile Dysfunction and Death), and not only in men (Cholesterol and Female Sexual Dysfunction). My latest on the topic is Best Foods to Improve Sexual Function.

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. Image has been modified.

Original Link

Foods that Affect Testosterone Levels

Foods that Affect Testosterone Levels.jpeg

A number of studies suggest that exposure to industrial pollutants may affect sexual function, for example, loss of libido, sexual dysfunction, and impotence. This may be due to effects on testosterone levels. In a study of men who ate a lot of contaminated fish, an elevation in PCB levels in the blood was associated with a lower concentration of testosterone levels. These pollutants are found predominantly in fish, but also meat and dairy. The lowest levels are found in plants (see Dietary Pollutants May Affect Testosterone Levels).

Testosterone doesn't just play a role in the determination of secondary sex characteristics like facial hair at puberty. It also regulates normal sexual functioning and the overall physical and psychological well-being of adult men. Abnormally low levels of testosterone can lead to decreased physical endurance and memory capacity, loss of libido, drop in sperm count, loss of bone density, obesity, and depression.

Endocrine-disrupting compounds that build up in fish may be able to mimic or block hormone receptors, or alter rates of synthesis or breakdown of sex steroid hormones. In children, these pollutants may actually impair sexual development. Boys who are exposed may grow up with smaller penises (although only by about two-thirds of an inch shorter at most). Researchers have tried exposing cells from aborted fetal human penises to these kinds of dietary pollutants, and gene expression related to genital development is indeed affected at real-life exposure levels. We're not sure if the effects on penis length are due to the pro-estrogenic effects of the toxins, though, or the anti-testosterone effects.

You've heard of save the whales? Well, male reproductive organs may be at risk from environmental hazards as well.

I previously addressed how we discovered the endocrine disruptor phenomenon in Alkylphenol Endocrine Disruptors and Allergies, as well as where they're found (Dietary Sources of Alkylphenol Endocrine Disruptors).

For more on sustaining male virility, see Male Fertility and Diet, The Role of Diet in Declining Sperm Counts, and Dairy Estrogen and Male Fertility.

I've talked about the role a plastics chemical may play in male sexual functioning (BPA Plastic and Male Sexual Dysfunction). But it's not just toxins, it's the total diet (Survival of the Firmest: Erectile Dysfunction and Death), and not only in men (Cholesterol and Female Sexual Dysfunction). My latest on the topic is Best Foods to Improve Sexual Function.

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. 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

What Are the Benefits of Organic?

What Are the Benefits of Organic?.jpeg

The medical literature has been historically hostile to organic foods, blaming in part erroneous information supplied by the health food movement for our ignorance of nutrition. But until just a few generations ago, all food was organic. It's kind of ironic that what we now call conventional food really isn't very conventional for our species.

By eating organic we can reduce our exposure to pesticides, but it remains unclear whether such a reduction in exposure is clinically relevant. In my video, Are Organic Foods Safer?, I talked about some of the test tube studies comparing health-related properties of organic versus conventional foods. Organic produce was found to have higher antioxidant and antimutagenic activity combined with better inhibition of cancer cell proliferation, but in terms of studies on actual people rather than petri dishes, there isn't much science either way.

Why can't you just compare the health of those who buy organic to those who don't? Organic consumers do report being significantly healthier than conventional consumers, but they also tend to eat more plant foods in general and less soda and alcohol, processed meat, or milk, and just eat healthier in general. No wonder they feel so much better!

Therefore, there is an urgent need for interventional trials, or studies following cohorts of people eating organic over time like the Million Women Study in the UK, which was the first to examine the association between the consumption of organic food and subsequent risk of cancer. The only significant risk reduction they found, though, was for non-Hodgkin's lymphoma. This is consistent with data showing a higher risk of developing lymphoma in those who have higher levels of pesticides stored in their butt fat, a study undertaken because farmworkers have been found to have higher rates of lymphoma.

Parental farmworker exposure is also associated with a birth defect of the penis called hypospadias, and so researchers decided to see if moms who failed to choose organic were at increased risk. Indeed they found that frequent consumption of conventional high-fat dairy products was associated with about double the odds of the birth defect. This could just be because those that choose organic have other related healthy behaviors, or it could be that high-fat foods like dairy products bioamplify the fat-soluble toxins in our environment.

In my video, Are Organic Foods Healthier?, you can see two other general population pesticide studies that have raised concerns. One study found about a 50 to 70% increase in the odds of ADHD among children with pesticide levels in their urine, and another that found triple the odds of testicular cancer among men with higher levels of organochlorine pesticides in their blood. 90% of such pollutants come from fish, meat, and dairy, which may help explain rising testicular cancer rates in many western countries since World War II.

What about interventional trials? All we have in the medical literature so far are studies showing organically grown food provides health benefits to fruit flies raised on diets of conventional versus organic produce when subjected to a variety of tests designed to assess overall fly health. And what do you know--flies raised on diets made from organically grown produce lived longer. Hmm, insects eating insecticides don't do as well. Not exactly much of a breakthrough!


For how to best get pesticides off of conventional produce, see my video How to Make Your Own Fruit and Vegetable Wash.

Pesticides are one thing, but Are Organic Foods More Nutritious?

Overall, Are the Benefits of Organic Food Underrated or Overrated?

For more on the impact of food contaminants during pregnancy, see:

In health,

Michael Greger, M.D.

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

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

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What Are the Benefits of Organic?

What Are the Benefits of Organic?.jpeg

The medical literature has been historically hostile to organic foods, blaming in part erroneous information supplied by the health food movement for our ignorance of nutrition. But until just a few generations ago, all food was organic. It's kind of ironic that what we now call conventional food really isn't very conventional for our species.

By eating organic we can reduce our exposure to pesticides, but it remains unclear whether such a reduction in exposure is clinically relevant. In my video, Are Organic Foods Safer?, I talked about some of the test tube studies comparing health-related properties of organic versus conventional foods. Organic produce was found to have higher antioxidant and antimutagenic activity combined with better inhibition of cancer cell proliferation, but in terms of studies on actual people rather than petri dishes, there isn't much science either way.

Why can't you just compare the health of those who buy organic to those who don't? Organic consumers do report being significantly healthier than conventional consumers, but they also tend to eat more plant foods in general and less soda and alcohol, processed meat, or milk, and just eat healthier in general. No wonder they feel so much better!

Therefore, there is an urgent need for interventional trials, or studies following cohorts of people eating organic over time like the Million Women Study in the UK, which was the first to examine the association between the consumption of organic food and subsequent risk of cancer. The only significant risk reduction they found, though, was for non-Hodgkin's lymphoma. This is consistent with data showing a higher risk of developing lymphoma in those who have higher levels of pesticides stored in their butt fat, a study undertaken because farmworkers have been found to have higher rates of lymphoma.

Parental farmworker exposure is also associated with a birth defect of the penis called hypospadias, and so researchers decided to see if moms who failed to choose organic were at increased risk. Indeed they found that frequent consumption of conventional high-fat dairy products was associated with about double the odds of the birth defect. This could just be because those that choose organic have other related healthy behaviors, or it could be that high-fat foods like dairy products bioamplify the fat-soluble toxins in our environment.

In my video, Are Organic Foods Healthier?, you can see two other general population pesticide studies that have raised concerns. One study found about a 50 to 70% increase in the odds of ADHD among children with pesticide levels in their urine, and another that found triple the odds of testicular cancer among men with higher levels of organochlorine pesticides in their blood. 90% of such pollutants come from fish, meat, and dairy, which may help explain rising testicular cancer rates in many western countries since World War II.

What about interventional trials? All we have in the medical literature so far are studies showing organically grown food provides health benefits to fruit flies raised on diets of conventional versus organic produce when subjected to a variety of tests designed to assess overall fly health. And what do you know--flies raised on diets made from organically grown produce lived longer. Hmm, insects eating insecticides don't do as well. Not exactly much of a breakthrough!


For how to best get pesticides off of conventional produce, see my video How to Make Your Own Fruit and Vegetable Wash.

Pesticides are one thing, but Are Organic Foods More Nutritious?

Overall, Are the Benefits of Organic Food Underrated or Overrated?

For more on the impact of food contaminants during pregnancy, see:

In health,

Michael Greger, M.D.

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

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

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The Food Safety Risk of Organic versus Conventional

The Food Safety Risk of Organic versus Conventional.jpeg

The stated principles of organic agriculture are "health, ecology, fairness, and care," but if you ask people why they buy organic, the strongest predictor is concern for their own health. People appear to spend more for organic foods for selfish reasons, rather than altruistic motives. Although organic foods may not have more nutrients per dollar (see my video Are Organic Foods More Nutritious?), consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

Food safety-wise, researchers found no difference in the risk for contamination with food poisoning bacteria in general. Both organic and conventional animal products have been found to be commonly contaminated with Salmonella and Campylobacter, for example. Most chicken samples (organic and inorganic), were found to be contaminated with Campylobacter, and about a third with Salmonella, but the risk of exposure to multidrug-resistant bacteria was lower with the organic meat. They both may carry the same risk of making us sick, but food poisoning from organic meat may be easier for doctors to treat.

What about the pesticides? There is a large body of evidence on the relation between exposure to pesticides and elevated rate of chronic diseases such as different types of cancers, diabetes, neurodegenerative disorders like Parkinson's, Alzheimer's, and ALS, as well as birth defects and reproductive disorders--but these studies were largely on people who live or work around pesticides.

Take Salinas Valley California, for example, where they spray a half million pounds of the stuff. Daring to be pregnant in an agricultural community like that may impair childhood brain development, such that pregnant women with the highest levels running through their bodies (as measured in their urine) gave birth to children with an average deficit of about seven IQ points. Twenty-six out of 27 studies showed negative effects of pesticides on brain development in children. These included attention problems, developmental disorders, and short-term memory difficulties.

Even in urban areas, if you compare kids born with higher levels of a common insecticide in their umbilical cord blood, those who were exposed to higher levels are born with brain anomalies. And these were city kids, so presumably this was from residential pesticide use.

Using insecticides inside your house may also be a contributing risk factor for childhood leukemia. Pregnant farmworkers may be doubling the odds of their child getting leukemia and increase their risk of getting a brain tumor. This has lead to authorities advocating that awareness of the potentially negative health outcome for children be increased among populations occupationally exposed to pesticides, though I don't imagine most farmworkers have much of a choice.

Conventional produce may be bad for the pregnant women who pick them, but what about our own family when we eat them?

Just because we spray pesticides on our food in the fields doesn't necessarily mean it ends up in our bodies when we eat it, or at least we didn't know that until a study was published in 2006. Researchers measured the levels of two pesticides running through children's bodies by measuring specific pesticide breakdown products in their urine. In my video, Are Organic Foods Safer?, you can see the levels of pesticides flowing through the bodies of three to 11-year olds during a few days on a conventional diet. The kids then went on an organic diet for five days and then back to the conventional diet. As you can see, eating organic provides a dramatic and immediate protective effect against exposures to pesticides commonly used in agricultural production. The study was subsequently extended. It's clear by looking at the subsequent graph in the video when the kids were eating organic versus conventional. What about adults, though? We didn't know... until now.

Thirteen men and women consumed a diet of at least 80% organic or conventional food for seven days and then switched. No surprise, during the mostly organic week, pesticide exposure was significantly reduced by a nearly 90% drop.

If it can be concluded that consumption of organic foods provides protection against pesticides, does that also mean protection against disease? We don't know. The studies just haven't been done. Nevertheless, in the meantime, the consumption of organic food provides a logical precautionary approach.

For more on organic foods:

For more on the infectious disease implications of organic versus conventional, see Superbugs in Conventional vs. Organic Chicken. Organic produce may be safer too. See Norovirus Food Poisoning from Pesticides. Organic eggs may also have lower Salmonella risk, which is an egg-borne epidemic every year in the US. See my video Who Says Eggs Aren't Healthy or Safe?

More on Parkinson's and pesticides in Preventing Parkinson's Disease With Diet.

Those surprised by the California data might have missed my video California Children Are Contaminated.

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: IFPRI -IMAGES / Flickr. This image has been modified.

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