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 Happened to the Rice Diet?

What Happened to the Rice Diet?.jpeg

During his career at Duke, Dr. Walter Kempner treated more than 18,000 patients with his rice diet. The diet was originally designed as a treatment for kidney failure and out-of-control high blood pressure at a time when these diagnoses were essentially a death sentence. Patients who would have died in all other hospitals had a reasonable chance for survival if they came under Kempner's care.

The results were so dramatic that many experienced physicians suspected him of falsifying data, because he was essentially reversing terminal diseases with rice and fruit, diseases understood to be incurable by the best of modern medicine at the time. Intensive investigations into his clinic vindicated his work, however, which other researchers were then able to replicate and validate.

Kempner was criticized for his lack of controls, meaning that when patients came to him he didn't randomly allocate half to his rice treatment and put the other half on conventional therapy. Kempner argued that the patients each acted as their own controls. For example, one patient, after the medical profession threw everything they had at him, still had blood pressure as high as 220 over 160. A normal blood pressure is considered to be around 120 over 80--which is where Kempner's rice diet took him. Had the patient not been given the rice diet, his pressures might have been even lower, though: zero over zero, because he'd likely be dead. The "control group" in Kempner's day had a survival expectancy estimated at 6 months. To randomize patients to conventional care would be to randomize them to their deaths.

We can also compare those who stuck to the diet to those who didn't. In one study, of those who started the rice diet but then stopped it within a year, 80% died. For those who made it a year but then gave up the diet, instead of an 80% chance of dying, they had about a 50% chance, a flip of the coin. Of those that stuck with the program, 90% lived to tell the tale.

Beginning in the late 1950's, drugs became available that effectively reduced blood pressure and hypertension, leading to a decreased demand for the rice diet. What conclusions can we draw from this all-but-forgotten therapy for hypertension? Not only was it the first effective therapy for high blood pressure, it may be equal to or more effective than our current multi-drug treatments. See Drugs & the Demise of the Rice Diet.

This causes one to speculate on the current practice of placing patients on one drug, then another, and perhaps a third until the blood pressure is controlled, with lip-service advocacy of a moderate reduction in dietary sodium, fat, and protein intake. At the same time, the impressive effectiveness of the rice-fruit diet, which is able to quickly stop the leakage from our arteries, lower increased intracranial pressure, reduce heart size, reverse the ECG changes, reverse heart failure, reduce weight, and markedly improve diabetes, is ignored.

Should we return to the Kempner protocol of starting with the most effective therapy, saving drugs for patients who fail to respond or who are unable or unwilling to restrict their diet? Today many people follow a plant-based diet as a choice, which is similar to what Kempner was often able to transition people to. After their high blood pressure was cured by the rice diet, patients were often able to gradually transition to a less strenuous dietary regime without adding medications and with no return of the elevated blood pressure.

If the Kempner sequence of a strictest of strict plant-based diets to a saner plant-based type diet offers the quickest and best approach to effective therapy, why isn't it still in greater use? The powerful role of the pharmaceutical industry in steering medical care away from dietary treatment to medications should be noted. Who profits from dietary treatment? Who provides the support for investigation and the funds for clinical trials? There is more to overcome than just the patient's reluctance to change their diet.

What Kempner wrote to a patient in 1954 is as true now as it was 60 years ago:

"[D]rugs can be very useful if properly employed and used in conjunction with intensive dietary treatment. However, the real difficulty is that Hypertensive Vascular Disease with all its possible complications--heart disease, kidney disease, stroke, blindness--is still treated very casually, a striking contrast to the attitude toward cancer. Since patients, physicians, and the chemical industry prefer the taking, prescribing, and selling of drugs to a treatment inconvenient to patient and physician and of no benefit to the pharmaceutical industry, the mortality figures for these diseases are still rather appalling."

Despite hundreds of drugs on the market now, high blood pressure remains the #1 cause of death and disability in the world, killing off 9 million people a year. A whole food plant-based diet treats the underlying cause. As Dr. Kempner explained to a patient, "If you should find a heap of manure on your living room floor, I do not recommend that you go buy some Air-Wick [an air freshener] and perfume. I recommend that you get a bucket and shovel and a strong scrubbing brush. Then, when your living room floor is clean again, why, you may certainly apply some Air-Wick if you wish."

As the great physician Maimonides said about 800 years ago, any illness that can be treated by diet alone should be treated by no other means.

For background on this amazing story, see Kempner Rice Diet: Whipping Us Into Shape. He would be proud that there is a whole medical specialty now: Lifestyle Medicine: Treating the Causes of Disease.

This reminds me of the role statin cholesterol-lowering drugs have played in seducing people into the magic bullet approach, but as with all magic it appears to mostly be misdirection:

Check out a couple of my recent overview videos for more on this topic: How Not to Die from Heart Disease and Taking Personal Responsibility for Your Health.

In this day and age, What Diet Should Physician's Recommend?

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

What Happened to the Rice Diet?

What Happened to the Rice Diet?.jpeg

During his career at Duke, Dr. Walter Kempner treated more than 18,000 patients with his rice diet. The diet was originally designed as a treatment for kidney failure and out-of-control high blood pressure at a time when these diagnoses were essentially a death sentence. Patients who would have died in all other hospitals had a reasonable chance for survival if they came under Kempner's care.

The results were so dramatic that many experienced physicians suspected him of falsifying data, because he was essentially reversing terminal diseases with rice and fruit, diseases understood to be incurable by the best of modern medicine at the time. Intensive investigations into his clinic vindicated his work, however, which other researchers were then able to replicate and validate.

Kempner was criticized for his lack of controls, meaning that when patients came to him he didn't randomly allocate half to his rice treatment and put the other half on conventional therapy. Kempner argued that the patients each acted as their own controls. For example, one patient, after the medical profession threw everything they had at him, still had blood pressure as high as 220 over 160. A normal blood pressure is considered to be around 120 over 80--which is where Kempner's rice diet took him. Had the patient not been given the rice diet, his pressures might have been even lower, though: zero over zero, because he'd likely be dead. The "control group" in Kempner's day had a survival expectancy estimated at 6 months. To randomize patients to conventional care would be to randomize them to their deaths.

We can also compare those who stuck to the diet to those who didn't. In one study, of those who started the rice diet but then stopped it within a year, 80% died. For those who made it a year but then gave up the diet, instead of an 80% chance of dying, they had about a 50% chance, a flip of the coin. Of those that stuck with the program, 90% lived to tell the tale.

Beginning in the late 1950's, drugs became available that effectively reduced blood pressure and hypertension, leading to a decreased demand for the rice diet. What conclusions can we draw from this all-but-forgotten therapy for hypertension? Not only was it the first effective therapy for high blood pressure, it may be equal to or more effective than our current multi-drug treatments. See Drugs & the Demise of the Rice Diet.

This causes one to speculate on the current practice of placing patients on one drug, then another, and perhaps a third until the blood pressure is controlled, with lip-service advocacy of a moderate reduction in dietary sodium, fat, and protein intake. At the same time, the impressive effectiveness of the rice-fruit diet, which is able to quickly stop the leakage from our arteries, lower increased intracranial pressure, reduce heart size, reverse the ECG changes, reverse heart failure, reduce weight, and markedly improve diabetes, is ignored.

Should we return to the Kempner protocol of starting with the most effective therapy, saving drugs for patients who fail to respond or who are unable or unwilling to restrict their diet? Today many people follow a plant-based diet as a choice, which is similar to what Kempner was often able to transition people to. After their high blood pressure was cured by the rice diet, patients were often able to gradually transition to a less strenuous dietary regime without adding medications and with no return of the elevated blood pressure.

If the Kempner sequence of a strictest of strict plant-based diets to a saner plant-based type diet offers the quickest and best approach to effective therapy, why isn't it still in greater use? The powerful role of the pharmaceutical industry in steering medical care away from dietary treatment to medications should be noted. Who profits from dietary treatment? Who provides the support for investigation and the funds for clinical trials? There is more to overcome than just the patient's reluctance to change their diet.

What Kempner wrote to a patient in 1954 is as true now as it was 60 years ago:

"[D]rugs can be very useful if properly employed and used in conjunction with intensive dietary treatment. However, the real difficulty is that Hypertensive Vascular Disease with all its possible complications--heart disease, kidney disease, stroke, blindness--is still treated very casually, a striking contrast to the attitude toward cancer. Since patients, physicians, and the chemical industry prefer the taking, prescribing, and selling of drugs to a treatment inconvenient to patient and physician and of no benefit to the pharmaceutical industry, the mortality figures for these diseases are still rather appalling."

Despite hundreds of drugs on the market now, high blood pressure remains the #1 cause of death and disability in the world, killing off 9 million people a year. A whole food plant-based diet treats the underlying cause. As Dr. Kempner explained to a patient, "If you should find a heap of manure on your living room floor, I do not recommend that you go buy some Air-Wick [an air freshener] and perfume. I recommend that you get a bucket and shovel and a strong scrubbing brush. Then, when your living room floor is clean again, why, you may certainly apply some Air-Wick if you wish."

As the great physician Maimonides said about 800 years ago, any illness that can be treated by diet alone should be treated by no other means.

For background on this amazing story, see Kempner Rice Diet: Whipping Us Into Shape. He would be proud that there is a whole medical specialty now: Lifestyle Medicine: Treating the Causes of Disease.

This reminds me of the role statin cholesterol-lowering drugs have played in seducing people into the magic bullet approach, but as with all magic it appears to mostly be misdirection:

Check out a couple of my recent overview videos for more on this topic: How Not to Die from Heart Disease and Taking Personal Responsibility for Your Health.

In this day and age, What Diet Should Physician's Recommend?

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 to Prevent Kidney Stones

The Best Diet to Prevent Kidney Stones.jpeg

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

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

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

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

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

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

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

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

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

In health,

Michael Greger, M.D.

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

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

Original Link

The Best Diet to Prevent Kidney Stones

The Best Diet to Prevent Kidney Stones.jpeg

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

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

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

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

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

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

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

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

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

In health,

Michael Greger, M.D.

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

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

Original Link

Are the Benefits of Organic Food Underrated or Overrated?

Vegsource.jpeg

Pesticides have been classified as probable carcinogens for 25 years. Different pesticides have been associated with different cancers through a variety of mechanisms, including genetic damage--direct hits to our DNA or chromosomes--and epigenetic modification, changes in the way our genes are expressed. These effects have been documented in workers who are spraying the pesticides, but exposure to pesticide residues that remain on food is much smaller.

More recently, higher cancer rates have also been noted in people who live in areas where pesticides are heavily sprayed, but what about the food we buy at the store? Organic fruits and vegetables have fewer pesticides, but even the levels on conventional produce are generally well below acceptable limits. There is still scientific controversy about the safety of some pesticides even under the regulatory limits, however, given the possible additive effects of the mixture of pesticides to which we're exposed. The pesticide approval process also doesn't take into account toxic breakdown products such as dioxins that can form once pesticides are released into the environment.

Cadmium is another issue. In the largest review to date, involving hundreds of studies, not only did organic foods have more antioxidant phytonutrients, but lower concentrations of cadmium. Cadmium is one of three highly toxic heavy metals (along with lead and mercury) found in the food supply. Cadmium accumulates in the body, so we should try to keep intake as low as possible. Organic crops only have about half the cadmium, which is thought to come from the phosphate fertilizers that are added to conventional crops.

Of course, not all organic foods are healthy. The organic food industry is now worth tens of billions of dollars, and they didn't get that way just selling carrots. We can now buy pesticide-free potato chips and organic jelly beans. Organic foods can be even worse because, for example, people falsely judge organic Oreo cookies to have fewer calories than conventional Oreos, and so may eat more. Forgoing exercise was deemed more acceptable when the person had just chosen an organic dessert rather than a conventional one. In fact, leniency toward forgoing exercise was slightly greater after choosing an organic dessert than after eating no dessert at all--organic cookies were effectively viewed as having negative calories! Organic junk food is still junk food.

Not only do people tend to overestimate the nutritional benefits of organic foods, they also overestimate the risks of pesticides. People think that as many people die from pesticide residues on conventional food as die in motor vehicle accidents in the United States. Surveys have found organic food buyers may think eating conventional produce is almost as bad as smoking a pack of cigarettes. That kind of thinking is dangerous because it could potentially lead to a decrease in overall fruit and vegetable consumption.

If just half of the U.S. population were to increase fruit and vegetable consumption by a single serving a day, an estimated 20,000 cancer cases might be avoided each year. That's how powerful produce may be. But, because the model was using conventional fruits and veggies, the pesticide burden from those extra fruits and vegetables might result in 10 additional cancer cases. So overall, if half of us ate one more serving, we'd just prevent 19,990 cases of cancer a year.

Now that was a paper written by scientists-for-hire paid for by the Alliance for Food and Farming, which is a bunch of conventional produce growers, so they probably exaggerated the benefits and minimized the risks, but I think the bottom line is sound. We get a tremendous benefit from eating conventional fruits and vegetables that far outweighs whatever tiny bump in risk we may get from the pesticides. Why not reap the benefits without the risk and choose organic? Great! But we should never let concern about pesticides stop us from stuffing our face with as many fruits and vegetables as possible.

My video, Are the Benefits of Organic Food Underrated or Overrated?, was the final installment of a 5-part series on organics. The first four videos are:

I've covered the issue of cadmium in our diet before in Cadmium and Cancer: Plant vs. Animal Foods and Male Fertility and Diet. Heavy metals are found concentrated in seafood and organ meats, but can also be found in certain supplements and protein powders.

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

Are the Benefits of Organic Food Underrated or Overrated?

Vegsource.jpeg

Pesticides have been classified as probable carcinogens for 25 years. Different pesticides have been associated with different cancers through a variety of mechanisms, including genetic damage--direct hits to our DNA or chromosomes--and epigenetic modification, changes in the way our genes are expressed. These effects have been documented in workers who are spraying the pesticides, but exposure to pesticide residues that remain on food is much smaller.

More recently, higher cancer rates have also been noted in people who live in areas where pesticides are heavily sprayed, but what about the food we buy at the store? Organic fruits and vegetables have fewer pesticides, but even the levels on conventional produce are generally well below acceptable limits. There is still scientific controversy about the safety of some pesticides even under the regulatory limits, however, given the possible additive effects of the mixture of pesticides to which we're exposed. The pesticide approval process also doesn't take into account toxic breakdown products such as dioxins that can form once pesticides are released into the environment.

Cadmium is another issue. In the largest review to date, involving hundreds of studies, not only did organic foods have more antioxidant phytonutrients, but lower concentrations of cadmium. Cadmium is one of three highly toxic heavy metals (along with lead and mercury) found in the food supply. Cadmium accumulates in the body, so we should try to keep intake as low as possible. Organic crops only have about half the cadmium, which is thought to come from the phosphate fertilizers that are added to conventional crops.

Of course, not all organic foods are healthy. The organic food industry is now worth tens of billions of dollars, and they didn't get that way just selling carrots. We can now buy pesticide-free potato chips and organic jelly beans. Organic foods can be even worse because, for example, people falsely judge organic Oreo cookies to have fewer calories than conventional Oreos, and so may eat more. Forgoing exercise was deemed more acceptable when the person had just chosen an organic dessert rather than a conventional one. In fact, leniency toward forgoing exercise was slightly greater after choosing an organic dessert than after eating no dessert at all--organic cookies were effectively viewed as having negative calories! Organic junk food is still junk food.

Not only do people tend to overestimate the nutritional benefits of organic foods, they also overestimate the risks of pesticides. People think that as many people die from pesticide residues on conventional food as die in motor vehicle accidents in the United States. Surveys have found organic food buyers may think eating conventional produce is almost as bad as smoking a pack of cigarettes. That kind of thinking is dangerous because it could potentially lead to a decrease in overall fruit and vegetable consumption.

If just half of the U.S. population were to increase fruit and vegetable consumption by a single serving a day, an estimated 20,000 cancer cases might be avoided each year. That's how powerful produce may be. But, because the model was using conventional fruits and veggies, the pesticide burden from those extra fruits and vegetables might result in 10 additional cancer cases. So overall, if half of us ate one more serving, we'd just prevent 19,990 cases of cancer a year.

Now that was a paper written by scientists-for-hire paid for by the Alliance for Food and Farming, which is a bunch of conventional produce growers, so they probably exaggerated the benefits and minimized the risks, but I think the bottom line is sound. We get a tremendous benefit from eating conventional fruits and vegetables that far outweighs whatever tiny bump in risk we may get from the pesticides. Why not reap the benefits without the risk and choose organic? Great! But we should never let concern about pesticides stop us from stuffing our face with as many fruits and vegetables as possible.

My video, Are the Benefits of Organic Food Underrated or Overrated?, was the final installment of a 5-part series on organics. The first four videos are:

I've covered the issue of cadmium in our diet before in Cadmium and Cancer: Plant vs. Animal Foods and Male Fertility and Diet. Heavy metals are found concentrated in seafood and organ meats, but can also be found in certain supplements and protein powders.

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 Way to Wash Fruit and Vegetables

The Best Way to Wash Fruit and Vegetables.jpeg

How might we reduce our exposure to pesticide residues on fruits and vegetables? What about staying away from imported produce? Well, it turns out domestic produce may be even worse, dispelling the notion that imported fruits and vegetables pose greater potential health risks to consumers.

Buying organic dramatically reduces dietary exposure to pesticides, but it does not eliminate the potential risk. Pesticide residues are detectable in about one in ten organic crop samples, due to cross-contamination from neighboring fields, the continued presence of very persistent pesticides like DDT in the soil, and accidental or fraudulent use.

By choosing organic, one hopes to shift exposures from a range of uncertain risk to more of a range of negligible risk, but even if all we had to eat were the most pesticide-laden of conventional produce, there is a clear consensus in the scientific community that the health benefits from consuming fruits and vegetables outweigh any potential risks from pesticide residues. And we can easily reduce whatever risk there is by rinsing our fruits and vegetables under running water.

There are, however, a plethora of products alleged by advertisers to reduce fruit and produce pesticide residues more effectively than water and touted to concerned consumers. For example, Procter & Gamble introduced a fruit and vegetable wash. As part of the introduction, T.G.I. Friday's jumped on board bragging on their menus that the cheese and bacon puddles they call potato skins were first washed with the new product. After all, it was proclaimed proven to be 98% more effective than water in removing pesticides.

So researchers put it to the test and it did no better than plain tap water.

Shortly thereafter Procter & Gamble discontinued the product, but numerous others took its place claiming their vegetable washes are three, four, five or even ten times more effective than water, to which a researcher replied, "That's mathematically impossible." If water removes 50%, you can't take off ten times more than 50%. They actually found water removed up to 80% of pesticide residues like the fungicide, Captan, for example. So, for veggie washes to brag they are three, four, five, ten times better than water is indeed mathematically questionable.

Other fruit and vegetable washes have since been put to the test. Researchers compared FIT Fruit & Vegetable Wash, Organiclean, Vegi-Clean, and dishwashing soap to just rinsing in plain tap water. 196 samples of lettuce, strawberries, and tomatoes were tested, and researchers found little or no difference between just rinsing with tap water compared to any of the veggie washes (or the dish soap). They all just seemed like a waste of money. The researchers concluded that just the mechanical action of rubbing the produce under tap water seemed to do it, and that using detergents or fruit and vegetable washes do not enhance the removal of pesticide residues from produce above that of just rinsing with tap water alone.

That may not be saying much, though. Captan appears to be the exception. When plain water was tried against a half dozen other pesticides, less than half the residues were removed.

Fingernail polish works better, but the goal is to end up with a less toxic, not a more toxic tomato.

We need a straightforward, plausible, and safe method for enhanced pesticide removal. Is there anything we can add to the water to boost its pesticide-stripping abilities? Check out my video, How to Make Your Own Fruit & Vegetable Wash.

If you soak potatoes in water, between about 2% to 13% of the pesticides are removed, but a 5% acetic acid solution removes up to 100%. What's that? Plain white vinegar. But 5% is full strength.

What about diluted vinegar? Diluted vinegar only seemed marginally better than tap water for removing pesticide residues. Using full strength vinegar would get expensive, though. Thankfully there's something cheaper that works even better: salt water.

A 10% salt solution appears to work as good or better than full-strength vinegar. To make a 10% salt solution you just have to mix up about one-part salt to nine-parts water (though make sure to rinse all of the salt off before eating!).

There's not much you can do for the pesticides in animal products, though. The top sources of some pesticides are fruits and vegetables; but for other pesticides, it's dairy, eggs, and meat because the chemicals build up in fat. What do you do about pesticides in animal products? Hard boiling eggs appears to destroy more pesticides that scrambling, but for the pesticides that build up in the fat in fish or chicken, cooking can sometimes increase pesticide levels that obviously can't just wash off. In fact, washing meat, poultry, or eggs is considered one of the top ten dangerous food safety mistakes.

For more on organic foods, see:

The most important reason to wash produce is to reduce the risk of food-borne illness. Ironically, the food poisoning viruses may be found in the pesticides themselves. Check out my video Norovirus Food Poisoning from Pesticides.

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