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

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

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.

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.

Original Link

What Animal Protein Does in Your Colon

What Animal Protein Does in Your Colon.jpeg

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

But I was wrong!

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

In health,

Michael Greger, M.D.

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

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

Original Link

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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Deep Breathing Exercise for Nausea

Deep Breathing Exercise for Nausea.jpeg

One of the most common fears patients express when facing surgery is postoperative nausea, which can range from minor queasiness to protracted periods of vomiting. Feeling sick to one's stomach and throwing up after surgery is a common problem, affecting between a quarter and a half of those placed under general anesthesia, and more than half of those at high risk (women who don't smoke and have a history of motion sickness).

I've explored the science behind treating nausea with ginger (see Natural Nausea Remedy Recipe), but if you're too nauseous to eat, what do you do? Well, people are often sent home with anti-nausea rectal suppositories. Surveys, however, show that cultural and sexual attitudes may make a number of people sensitive to anything involving the rectum. Though the wording of the question researchers asked was, "are you happy to have a drug put in your back passage?" I can imagine many of the respondents thinking "well, maybe I wouldn't so much mind, but wouldn't exactly be happy about it," especially when you're feeling sick and throwing up.

For women who've had a C-section, they might not want to take drugs at all if they're breastfeeding, so researchers decided to put aromatherapy to the test. Research has shown that essential oils of both spearmint and peppermint are effective in reducing nausea and vomiting after chemotherapy, but this was after swallowing them.

Would just the smell of peppermint help with nausea? I explore this in my video Peppermint Aromatherapy for Nausea. Researchers had women take deep whiffs of peppermint extract (like you'd buy at a store) and it seemed to work. Eighty percent of the mint-sniffers felt better within just a few minutes, compared to no improvement in the placebo group who sniffed water with green food coloring, or the control group who didn't sniff anything.

The study was criticized for being small and for not using pure peppermint oil. Peppermint extract is peppermint oil plus alcohol. Maybe it was the smell of alcohol that made people better? And that's actually not too much of a stretch. In 1997, researchers reported a simple, innocuous, and inexpensive treatment for postoperative nausea and vomiting--the smell of isopropyl alcohol, which is what is found in those alcohol wipes, the little prep pads that nurses swab you with before shots. They found that they could just effectively tear one open and wave it under someone's nose and relieve nausea and vomiting in more than 80% of folks after surgery. It has been since shown to work as well as a leading anti-nausea drug, and may even work faster, cutting nausea in half within 10 to 15 minutes, rather than 20 or 25.

So was it the alcohol, the peppermint, or both? Researchers decided to put it to the test. They instructed patients to take three slow, deep breaths, smelling alcohol, peppermint, or nothing. The smell of peppermint cut nausea in half within five minutes, and so did the alcohol. But so did smelling nothing! So maybe it had nothing to do with the scent; maybe it was just the instruction to take slow, deep breaths. That would make it a really cost-effective intervention. Maybe it shouldn't be so surprising, given the proximity of the vomiting and breathing centers within the brain.

And indeed, controlled breathing was found effective with or without any scent. So next time you feel nauseous, inhale deeply through your nose to the count of three, hold your breath to the count of three, and exhale out the mouth to the count of three. Do that three times.

Ironically, the researchers continued to advocate using those nasty smelling alcohol pads even though they themselves showed they weren't any more effective than breathing alone. Why? Since isopropyl alcohol has a readily detectable odor, patients are more likely to think that their post-operation nausea and vomiting is being actively treated when they inhale alcohol vapors rather than just engaging in breathing exercises.


What do you think of still using the alcohol pads even though they were shown to offer no additional benefit? I have a whole video on such questions: The Lie That Heals: Should Doctors Give Placebos?

For those who can swallow, I offer more about powdered ginger in my video Dangerous Advice From Health Food Store Employees.

There's more on aromatherapy here:

What about actually eating the peppermint?

Of course, the best way to avoid postsurgical nausea is to try to avoid surgery in the first place. Those that eat healthy may be less likely to go under the knife. See Say No to Drugs by Saying Yes to More Plants.

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

Deep Breathing Exercise for Nausea

Deep Breathing Exercise for Nausea.jpeg

One of the most common fears patients express when facing surgery is postoperative nausea, which can range from minor queasiness to protracted periods of vomiting. Feeling sick to one's stomach and throwing up after surgery is a common problem, affecting between a quarter and a half of those placed under general anesthesia, and more than half of those at high risk (women who don't smoke and have a history of motion sickness).

I've explored the science behind treating nausea with ginger (see Natural Nausea Remedy Recipe), but if you're too nauseous to eat, what do you do? Well, people are often sent home with anti-nausea rectal suppositories. Surveys, however, show that cultural and sexual attitudes may make a number of people sensitive to anything involving the rectum. Though the wording of the question researchers asked was, "are you happy to have a drug put in your back passage?" I can imagine many of the respondents thinking "well, maybe I wouldn't so much mind, but wouldn't exactly be happy about it," especially when you're feeling sick and throwing up.

For women who've had a C-section, they might not want to take drugs at all if they're breastfeeding, so researchers decided to put aromatherapy to the test. Research has shown that essential oils of both spearmint and peppermint are effective in reducing nausea and vomiting after chemotherapy, but this was after swallowing them.

Would just the smell of peppermint help with nausea? I explore this in my video Peppermint Aromatherapy for Nausea. Researchers had women take deep whiffs of peppermint extract (like you'd buy at a store) and it seemed to work. Eighty percent of the mint-sniffers felt better within just a few minutes, compared to no improvement in the placebo group who sniffed water with green food coloring, or the control group who didn't sniff anything.

The study was criticized for being small and for not using pure peppermint oil. Peppermint extract is peppermint oil plus alcohol. Maybe it was the smell of alcohol that made people better? And that's actually not too much of a stretch. In 1997, researchers reported a simple, innocuous, and inexpensive treatment for postoperative nausea and vomiting--the smell of isopropyl alcohol, which is what is found in those alcohol wipes, the little prep pads that nurses swab you with before shots. They found that they could just effectively tear one open and wave it under someone's nose and relieve nausea and vomiting in more than 80% of folks after surgery. It has been since shown to work as well as a leading anti-nausea drug, and may even work faster, cutting nausea in half within 10 to 15 minutes, rather than 20 or 25.

So was it the alcohol, the peppermint, or both? Researchers decided to put it to the test. They instructed patients to take three slow, deep breaths, smelling alcohol, peppermint, or nothing. The smell of peppermint cut nausea in half within five minutes, and so did the alcohol. But so did smelling nothing! So maybe it had nothing to do with the scent; maybe it was just the instruction to take slow, deep breaths. That would make it a really cost-effective intervention. Maybe it shouldn't be so surprising, given the proximity of the vomiting and breathing centers within the brain.

And indeed, controlled breathing was found effective with or without any scent. So next time you feel nauseous, inhale deeply through your nose to the count of three, hold your breath to the count of three, and exhale out the mouth to the count of three. Do that three times.

Ironically, the researchers continued to advocate using those nasty smelling alcohol pads even though they themselves showed they weren't any more effective than breathing alone. Why? Since isopropyl alcohol has a readily detectable odor, patients are more likely to think that their post-operation nausea and vomiting is being actively treated when they inhale alcohol vapors rather than just engaging in breathing exercises.


What do you think of still using the alcohol pads even though they were shown to offer no additional benefit? I have a whole video on such questions: The Lie That Heals: Should Doctors Give Placebos?

For those who can swallow, I offer more about powdered ginger in my video Dangerous Advice From Health Food Store Employees.

There's more on aromatherapy here:

What about actually eating the peppermint?

Of course, the best way to avoid postsurgical nausea is to try to avoid surgery in the first place. Those that eat healthy may be less likely to go under the knife. See Say No to Drugs by Saying Yes to More Plants.

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