What a Single Fatty Meal Can Do to Our Arteries

Oct12 Fatty Meal copy.jpeg

The phenomenon of postprandial angina was described more than 200 years ago: chest pain that occurs after a meal, even if you're just sitting down and resting. This could be intuitively attributed to redistribution of blood flow away from the heart to the gut during digestion. However, such a mechanism could not be demonstrated experimentally.

The problem appears to be within the coronary arteries themselves. The clue came in 1955 when researchers found they could induce angina in people with heart disease just by having them drink fat. My video Fatty Meals May Impair Artery Function includes a fascinating graph of so-called lactescence, or milkiness, over time. It shows how their blood became increasingly milky with fat over the next five hours, and each of the ten attacks of angina was found to occur about four-and-a-half to five hours after the fatty meal, right when blood milkiness was at or near its peak. After a nonfat meal with the same bulk and calories, but made out of starch, sugar, and protein, no anginal pain was elicited in any of the patients.

To understand how the mere presence of fat in the blood can affect blood flow to the heart, we need to understand the endothelium, the inner lining of all of our blood vessels. Our arteries are not just rigid pipes; they are living, breathing organs that actively dilate or constrict, thinning or thickening the blood and releasing hormones, depending on what's needed. This is all controlled by the single inner layer, the endothelium, which makes it the body's largest endocrine (hormone-secreting) organ. When it's all gathered up, the endothelium weighs a total of three pounds and has a combined surface area of 700 square yards.

We used to think the endothelium was just an inert layer lining our vascular tree, but now we know better:

Researchers found that low-fat meals tend to improve endothelial function, whereas high-fat meals tend to worsen it. This goes for animal fat, as well as isolated plant fats, such as sunflower oil. But, maybe it's just the digestion of fat rather than the fat itself? Our body can detect the presence of fat in the digestive tract and release a special group of hormones and enzymes. Researchers tried feeding people fake fat and found that the real fat deprived the heart of blood while the fake fat didn't. Is our body really smart enough to tell the difference?

A follow-up study settled the issue. Researchers tried infusing fat directly into people's bloodstream through an IV to sneak it past your mouth and brain. Within hours, their arteries stiffened, significantly crippling their ability to relax and dilate normally. So it was the fat after all! This decrease in the ability to vasodilate coronary arteries after a fatty meal, just when you need it, could explain the phenomenon of after-meal angina in patients with known coronary artery disease.


This effect could certainly help explain the findings in Low Carb Diets and Coronary Blood Flow. My video Olive Oil and Artery Function addresses less refined fats like extra virgin olive oil,.

For more on angina, see the beginning of my 2014 annual talk--From Table to Able: Combating Disabling Diseases with Food--and How Not to Die from Heart Disease.

Another consequence of endothelial dysfunction is lack of blood flow to other organs. Check out Survival of the Firmest: Erectile Dysfunction and Death and Atkins Diet: Trouble Keeping It Up.

Fat in the bloodstream can also impair our ability to control blood sugar levels. Learn more with What Causes Insulin Resistance?, The Spillover Effect Links Obesity to Diabetes, and Lipotoxicity: How Saturated Fat Raises Blood Sugar.

Finally, for more on how diet affects our arteries, check out Tea and Artery Function, Vinegar and Artery Function, and Plant-Based Diets and Artery Function.

In health,

Michael Greger, M.D.

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

Original Link

What a Single Fatty Meal Can Do to Our Arteries

Oct12 Fatty Meal copy.jpeg

The phenomenon of postprandial angina was described more than 200 years ago: chest pain that occurs after a meal, even if you're just sitting down and resting. This could be intuitively attributed to redistribution of blood flow away from the heart to the gut during digestion. However, such a mechanism could not be demonstrated experimentally.

The problem appears to be within the coronary arteries themselves. The clue came in 1955 when researchers found they could induce angina in people with heart disease just by having them drink fat. My video Fatty Meals May Impair Artery Function includes a fascinating graph of so-called lactescence, or milkiness, over time. It shows how their blood became increasingly milky with fat over the next five hours, and each of the ten attacks of angina was found to occur about four-and-a-half to five hours after the fatty meal, right when blood milkiness was at or near its peak. After a nonfat meal with the same bulk and calories, but made out of starch, sugar, and protein, no anginal pain was elicited in any of the patients.

To understand how the mere presence of fat in the blood can affect blood flow to the heart, we need to understand the endothelium, the inner lining of all of our blood vessels. Our arteries are not just rigid pipes; they are living, breathing organs that actively dilate or constrict, thinning or thickening the blood and releasing hormones, depending on what's needed. This is all controlled by the single inner layer, the endothelium, which makes it the body's largest endocrine (hormone-secreting) organ. When it's all gathered up, the endothelium weighs a total of three pounds and has a combined surface area of 700 square yards.

We used to think the endothelium was just an inert layer lining our vascular tree, but now we know better:

Researchers found that low-fat meals tend to improve endothelial function, whereas high-fat meals tend to worsen it. This goes for animal fat, as well as isolated plant fats, such as sunflower oil. But, maybe it's just the digestion of fat rather than the fat itself? Our body can detect the presence of fat in the digestive tract and release a special group of hormones and enzymes. Researchers tried feeding people fake fat and found that the real fat deprived the heart of blood while the fake fat didn't. Is our body really smart enough to tell the difference?

A follow-up study settled the issue. Researchers tried infusing fat directly into people's bloodstream through an IV to sneak it past your mouth and brain. Within hours, their arteries stiffened, significantly crippling their ability to relax and dilate normally. So it was the fat after all! This decrease in the ability to vasodilate coronary arteries after a fatty meal, just when you need it, could explain the phenomenon of after-meal angina in patients with known coronary artery disease.


This effect could certainly help explain the findings in Low Carb Diets and Coronary Blood Flow. My video Olive Oil and Artery Function addresses less refined fats like extra virgin olive oil,.

For more on angina, see the beginning of my 2014 annual talk--From Table to Able: Combating Disabling Diseases with Food--and How Not to Die from Heart Disease.

Another consequence of endothelial dysfunction is lack of blood flow to other organs. Check out Survival of the Firmest: Erectile Dysfunction and Death and Atkins Diet: Trouble Keeping It Up.

Fat in the bloodstream can also impair our ability to control blood sugar levels. Learn more with What Causes Insulin Resistance?, The Spillover Effect Links Obesity to Diabetes, and Lipotoxicity: How Saturated Fat Raises Blood Sugar.

Finally, for more on how diet affects our arteries, check out Tea and Artery Function, Vinegar and Artery Function, and Plant-Based Diets and Artery Function.

In health,

Michael Greger, M.D.

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

Original Link

Reversing Diabetic Blindness with Diet

Reversing Diabetic Blindness with Diet.jpeg

Though many reported feeling better on Dr. Walter Kempner's rice and fruit diet, he refused to accept such anecdotal evidence as proof of success. He wanted objective measurements. The most famous were his "eyegrounds photographs," taken with a special camera that allowed one to visualize the back of the eye. In doing so, he proved diet can arrest the bleeding, oozing, and swelling you see in the back of the eye in people with severe kidney, hypertensive, or heart disease. Even more than that, he proved that diet could actually reverse it, something never thought possible.

In my video, Can Diabetic Retinopathy Be Reversed?, you can see before and after images of the back of patients' eyes. He found reversal to such a degree that even those who could no longer distinguish large objects were able to once again read fine print. Dr. Kempner had shown a reversal of blindness with diet.

The results were so dramatic that the head of the department of ophthalmology at Duke, where Kempner worked, was questioned as to whether they were somehow faked. He assured them they were not. In fact, he wrote in one person's chart, "This patient's eyegrounds are improved to an unbelievable degree." Not only had he never seen anything like it, he couldn't remember ever seeing a patient with such advanced disease even being alive 15 months later.

The magnitude of the improvements Kempner got--reversal of end-stage heart and kidney failure--was surprising, simply beyond belief. But as Kempner said as his closing sentence of a presentation before the American College of Physicians, "The important result is not that the change in the course of the disease has been achieved by the rice diet but that the course of the disease can be changed."

Now that we have high blood pressure drugs, we see less hypertensive retinopathy, but we still see a lot of diabetic retinopathy, now the leading cause of blindness in American adults. Even with intensive diabetes treatment--at least three insulin injections a day with the best modern technology has to offer--the best we can offer is usually just a slowing of the progression of the disease.

So, in the 21st century, we slow down your blindness. Yet a half century ago, Kempner proved we could reverse it. Kempner started out using his plant-based rice diet ultra-low in sodium, fat, cholesterol, and protein to reverse kidney and heart failure; he actually assumed the diet would make diabetes worse. He expected a 90% carbohydrate diet would increase insulin requirements, however, the opposite proved to be true. He took the next 100 patients with diabetes who walked through his door who went on the rice diet for at least three months and found their fasting blood sugars dropped despite a drop in the insulin they were taking. What really blew people away was this: Forty-four of the patients had diabetic retinopathy, and, in 30% of the cases, their eyes improved. That's not supposed to happen; diabetic retinopathy had been considered "a sign of irreversible destruction." What does this change mean in real life? Patients went from unable to even read headlines to normal vision.

The remarkable success Dr. Kempner had reversing some of the most dreaded complications of diabetes with his rice and fruit diet was not because of weight loss. The improvements occurred even in those patients who did not lose significant weight, so it must have been something specific about the diet. Maybe it was his total elimination of animal protein, animal fat, and cholesterol? Or perhaps it was his radical reduction in sodium, fat, and protein in general? We don't know.

How do we treat diabetic retinopathy these days? With steroids and other drugs injected straight into the eyeball. If that doesn't work, there's always pan-retinal laser photocoagulation, in which laser burns are etched over nearly the entire retina. Surgeons literally burn out the back of your eye. Why would they do that? The theory is that by killing off most of the retina, the little pieces you leave behind may get more blood flow.

When I see that, along with Kempner's work, I can't help but feel like history has been reversed. It seems as though it should have gone like, "Can you believe 50 years ago the best we had was this barbaric, burn-out-your-socket surgery? Thank goodness we've since learned that through dietary means alone, we can reverse the blindness." But instead of learning, medicine seems to have forgotten.

I documented the extraordinary Kempner story previously in Kempner Rice Diet: Whipping Us Into Shape and Drugs and the Demise of the Rice Diet. The reason I keep coming back to this is not to suggest people should go on such a diet (it is too extreme and potentially dangerous to do without strict medical supervision), but to show the power of dietary change to yield tremendous healing effects.

The best way to prevent diabetic blindness is to prevent or reverse diabetes in the first place. See, for example:

Why wouldn't a diet of white rice make diabetes worse? See If White Rice Is Linked to Diabetes, What About China?

For more on the nitty gritty on what is the actual cause of type 2 diabetes, 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: Community Eye Health / Flickr. This image has been modified.

Original Link

Reversing Diabetic Blindness with Diet

Reversing Diabetic Blindness with Diet.jpeg

Though many reported feeling better on Dr. Walter Kempner's rice and fruit diet, he refused to accept such anecdotal evidence as proof of success. He wanted objective measurements. The most famous were his "eyegrounds photographs," taken with a special camera that allowed one to visualize the back of the eye. In doing so, he proved diet can arrest the bleeding, oozing, and swelling you see in the back of the eye in people with severe kidney, hypertensive, or heart disease. Even more than that, he proved that diet could actually reverse it, something never thought possible.

In my video, Can Diabetic Retinopathy Be Reversed?, you can see before and after images of the back of patients' eyes. He found reversal to such a degree that even those who could no longer distinguish large objects were able to once again read fine print. Dr. Kempner had shown a reversal of blindness with diet.

The results were so dramatic that the head of the department of ophthalmology at Duke, where Kempner worked, was questioned as to whether they were somehow faked. He assured them they were not. In fact, he wrote in one person's chart, "This patient's eyegrounds are improved to an unbelievable degree." Not only had he never seen anything like it, he couldn't remember ever seeing a patient with such advanced disease even being alive 15 months later.

The magnitude of the improvements Kempner got--reversal of end-stage heart and kidney failure--was surprising, simply beyond belief. But as Kempner said as his closing sentence of a presentation before the American College of Physicians, "The important result is not that the change in the course of the disease has been achieved by the rice diet but that the course of the disease can be changed."

Now that we have high blood pressure drugs, we see less hypertensive retinopathy, but we still see a lot of diabetic retinopathy, now the leading cause of blindness in American adults. Even with intensive diabetes treatment--at least three insulin injections a day with the best modern technology has to offer--the best we can offer is usually just a slowing of the progression of the disease.

So, in the 21st century, we slow down your blindness. Yet a half century ago, Kempner proved we could reverse it. Kempner started out using his plant-based rice diet ultra-low in sodium, fat, cholesterol, and protein to reverse kidney and heart failure; he actually assumed the diet would make diabetes worse. He expected a 90% carbohydrate diet would increase insulin requirements, however, the opposite proved to be true. He took the next 100 patients with diabetes who walked through his door who went on the rice diet for at least three months and found their fasting blood sugars dropped despite a drop in the insulin they were taking. What really blew people away was this: Forty-four of the patients had diabetic retinopathy, and, in 30% of the cases, their eyes improved. That's not supposed to happen; diabetic retinopathy had been considered "a sign of irreversible destruction." What does this change mean in real life? Patients went from unable to even read headlines to normal vision.

The remarkable success Dr. Kempner had reversing some of the most dreaded complications of diabetes with his rice and fruit diet was not because of weight loss. The improvements occurred even in those patients who did not lose significant weight, so it must have been something specific about the diet. Maybe it was his total elimination of animal protein, animal fat, and cholesterol? Or perhaps it was his radical reduction in sodium, fat, and protein in general? We don't know.

How do we treat diabetic retinopathy these days? With steroids and other drugs injected straight into the eyeball. If that doesn't work, there's always pan-retinal laser photocoagulation, in which laser burns are etched over nearly the entire retina. Surgeons literally burn out the back of your eye. Why would they do that? The theory is that by killing off most of the retina, the little pieces you leave behind may get more blood flow.

When I see that, along with Kempner's work, I can't help but feel like history has been reversed. It seems as though it should have gone like, "Can you believe 50 years ago the best we had was this barbaric, burn-out-your-socket surgery? Thank goodness we've since learned that through dietary means alone, we can reverse the blindness." But instead of learning, medicine seems to have forgotten.

I documented the extraordinary Kempner story previously in Kempner Rice Diet: Whipping Us Into Shape and Drugs and the Demise of the Rice Diet. The reason I keep coming back to this is not to suggest people should go on such a diet (it is too extreme and potentially dangerous to do without strict medical supervision), but to show the power of dietary change to yield tremendous healing effects.

The best way to prevent diabetic blindness is to prevent or reverse diabetes in the first place. See, for example:

Why wouldn't a diet of white rice make diabetes worse? See If White Rice Is Linked to Diabetes, What About China?

For more on the nitty gritty on what is the actual cause of type 2 diabetes, 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: Community Eye Health / Flickr. This image has been modified.

Original Link

Treating Kidney Stones with Diet

Treating Kidney Stones with Diet.jpeg

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

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

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

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

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

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

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

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

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

In health,

Michael Greger, M.D.

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

Image Credit: Sally Plank

Original Link

Treating Kidney Stones with Diet

Treating Kidney Stones with Diet.jpeg

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

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

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

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

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

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

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

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

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

In health,

Michael Greger, M.D.

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

Image Credit: Sally Plank

Original Link

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

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