How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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

How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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

How Much Fiber Should You Eat Every Day?

How Much Fiber Should You Eat Every Day.jpeg

High dietary fiber intake may help prevent strokes. The belief that dietary fiber intake is protectively associated with certain diseases was postulated 40 years ago and then enormously fueled and kept alive by a great body of science since. Today it is generally believed that eating lots of fiber-rich foods helps prevent obesity, diabetes, and cardiovascular diseases such as stroke.

Strokes are the second most common cause of death worldwide. Moreover, stroke is a leading cause of disability, and so preventing strokes in the first place--what's called primary prevention--should therefore, be a key public health priority (see How to Prevent a Stroke).

The best observational studies to date found that fiber appears to significantly protect against the risk of stroke. Different strokes for different folks, depending, evidently, on how much fiber they ate. Notably, increasing fiber just seven grams a day was associated with a 7% reduction in stroke risk. And seven grams is easy, that's like a serving of whole grain pasta with tomato sauce and an apple.

What's the mechanism? Maybe it's that fiber helps lower cholesterol and blood sugar levels. Or it could just be that those eating more fiber are just eating more vegetables, or fewer calories, or less meat and fat, or improving digestion, all of which may slim us down and lower our blood pressure and the amount of inflammation in our bodies. Does it really matter, though? As Dr. Burkitt commented on the biblical passage, "A man scatters seed on the land--the seed sprouts and opens--how, he does not know," the farmer doesn't wait to find out. Had the farmer postponed his sowing until he understood seed germination, he would not have lasted very long. So yes, let's keep trying to figure out why fiber is protective, but in the meanwhile, we should be increasing our intake of fiber, which is to say increasing our intake of whole plant foods.

It's never too early to start eating healthier. Strokes are one of many complications of arterial stiffness. Though our first stroke might not happen until our 50's, our arteries may have been stiffening for decades leading up to it. Hundreds of kids were followed for 24 years, from age 13 in through 36 and researchers found that lower intake of fiber during a young age was associated with stiffening of the arteries leading up to the brain. Even by age 13, they could see differences in arterial stiffness depending on diet. Fiber intake is important at any age.

Again, it doesn't take much. One extra apple a day or an extra quarter cup of broccoli might translate into meaningful differences in arterial stiffness in adulthood. If you really don't want a stroke, we should try to get 25 grams a day of soluble fiber (found concentrated in beans, oats, nuts, and berries) and 47 grams a day of insoluble fiber (concentrated in whole grains). One would have to eat an extraordinarily healthy diet to get that much, yet these cut-off values could be considered as the minimum recommended daily intake of soluble and insoluble fiber to prevent stroke. The researchers admit these are higher than those commonly and arbitrarily proposed as "adequate" levels by scientific societies, but should we care about what authorities think is practical? They should just share the best scienceand let us make up our own minds.

Someone funded by Kellogg's wrote in to complain that in practice, such fiber intakes are "unachievable" and that the message should just be the more, the better--like maybe just have a bowl of cereal or something.

The real Dr. Kellogg was actually one of our most famous physicians, credited for being one of the first to sound the alarm about smoking, and who may have been the first American physician to have recognized the field of nutrition as a science. He would be rolling in his grave today if he knew what his family's company had become.


More on preventing strokes can be found here:

More on the wonders of fiber in:

It really is never too early to start eating healthier. See, for example, Heart Disease Starts in Childhood, How to Prevent Prediabetes in Children, Heart Disease May Start in the Womb, and Should All Children Have their Cholesterol Checked?

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

Evidence-Based Nutrition

NF-Jan12 Evidence-Based Medicine or Evidence-Biased?.jpg

Dr. Esselstyn's landmark study, demonstrating that even advanced triple vessel coronary artery disease could be reversed with a plant-based diet, has been criticized for being such a small study. But the reason we're used to seeing large studies is that they typically show such small effects. Drug manufacturers may need to study 7,000 people in order to show a barely statistically significant 15% drop in ischemic events in a subsample of patients. Esselstyn achieved a 100% drop in those who stuck to his diet, all the more compelling considering that those 18 participants experienced 49 coronary events (like heart attacks) in the eight years before they went on the diet. These patients were the sickest of the sick, most of whom having already failed surgical intervention. When the effects are so dramatic, how many people do you need?

Before 1885, a symptomatic rabies infection was a death sentence, until little Joseph Meister became the first to receive Pasteur's experimental rabies vaccine. The results of this and one other case were so dramatic compared with previous experience that the new treatment was accepted with a sample size of two. That is, the results were so compelling that no randomized controlled trial was necessary. Having been infected by a rabid dog, would you be willing to participate in a randomized controlled trial, when being in the control group had a certainty of a ''most awful death''? Sadly, such a question is not entirely rhetorical.

In the 1970's, a revolutionary treatment for babies with immature lungs called "extracorporeal membranous oxygenation" (ECMO), transformed immature lung mortality from 80% dead to 80% alive nearly overnight. The standard therapy caused damage to infants' lungs and was a major cause of morbidity and mortality in infants. ECMO is much gentler on babies' lungs, "providing life support while allowing the lungs to 'rest.'"

Despite their dramatic success, the researchers who developed ECMO felt forced to perform a randomized controlled trial. They didn't want to; they knew they'd be condemning babies to death. They felt compelled to perform such a trial because their claim that ECMO worked would, they judged, carry little weight amongst their medical colleagues unless supported by a randomized controlled trial. Therefore, at Harvard's Children's Hospital, 39 infants were randomized to either get ECMO or conventional medical therapy. The researchers decided ahead of time to stop the trial after the 4th death so as not to kill too many babies. And that's what they did. The study was halted after the fourth conventional medical therapy death, at which point nine out of nine ECMO babies had survived. Imagine being the parent to one of those four children.

Similarly, imagine being the child of a parent who died other conventional medical or surgical therapy for heart disease.

In her paper "How evidence-based medicine biases physicians against nutrition," Laurie Endicott Thomas reminds us that medical students in the United States are taught very little about nutrition (See Evidence-Based Medicine or Evidence-Biased?). Worse yet, according to Thomas, their training actually biases them against the studies that show the power of dietary approaches to managing disease by encouraging them to ignore any information that does not come from a double-blind, randomized controlled trial. Yet humans cannot be blinded to a dietary intervention--we tend to notice what we're eating--and, as a result, physicians are biased in favor of drug treatments and against dietary interventions for the management of chronic disease.

Evidence-based medicine is a good thing. However, Thomas points out that the medical profession may be focusing too much on one type of evidence to the exclusion of all others. Unfortunately, this approach can easily degenerate into "ignoring-most-of-the-truly-important-evidence" based medicine.

Heart disease is a perfect example. On healthy enough plant based diets, our number one cause of death may simply cease to exist. The Cornell-Oxford-China Study showed that even small amounts of animal-based food was associated with a small, but measurable increase in the risk of some chronic diseases. In other words, "the causal relationship between dietary patterns and coronary artery disease was already well established before Dean Ornish and Caldwell Esselstyn undertook their clinical studies." The value of their studies was not so much in providing evidence that such a dietary change would be effective, but in showing that "physicians can persuade their patients to make such changes," and in "providing interesting data on the speed and magnitude of the change in severe atherosclerotic lesions as a result of dietary therapy."

Therefore, any complaints that these studies were small or unblinded are simply irrelevant. Because the evidence of the role of diet in causing atherosclerosis is already so overwhelming, "assigning a patient to a control group eating the standard American diet could be considered a violation of research ethics."

Evidence of the value of plant-based diets for managing chronic disease has been available in the medical literature for decades. Walter Kempner at Duke University, John McDougall, the Physician's Committee for Responsible Medicine, Nathan Pritikin, and Denis Burkitt all warned us that the standard Western diet is the standard cause of death and disability in the Western world. Yet physicians, especially in the US, are still busily manning the ambulances at the bottom of the cliff instead of building fences at the top.

If you're not familiar with Dr. Esselstyn's work, I touch on it in:

Sadly, medical students learn little about these powerful tools:

If you haven't heard of Pritikin, I introduce him here: Engineering a Cure

An intro to Dr. Ornish: Convergence of Evidence

Dr. Burkitt: Dr. Burkitt's F-Word Diet

The Cornell-Oxford-China Study: China Study on Sudden Cardiac Death

Dr. Walter Kempner: Kempner Rice Diet: Whipping Us Into Shape

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, From Table to Able, and Food as Medicine.

Image Credit: clement127 / Flickr

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Colon Cancer Prevention: Is it the Fiber or the Phytates?

NF - May21 Phytates for the Prevention of Cancer.jpg

Dietary factors are considered the most important environmental risk factors for cancer. Within recent years, a large number of naturally occurring health-enhancing substances of plant origin known as phytonutrients have been recognized to have beneficial effects on certain cancers. Beans, chickpeas, split peas and lentils are packed with all sorts of wonderful nutrients, but the reason they may protect against several degenerative diseases may be due to non-nutritive compounds, or even so-called "antinutrient" compounds like phytates.

Phytates have a somewhat negative reputation for binding to certain minerals (like iron, zinc and manganese) and slowing their absorption. But they have also been found to offer anti-inflammatory health benefits. "The reputation of phytate has had a roller coaster ride ever since its discovery; it has undergone alternate eminence and infamy." (I previously explored the surprising new science about phytates in my video Phytates for the Prevention of Osteoporosis). Could they play a potential role in preventing colon cancer?

In the U.S., colon cancer is the second leading cause of cancer death, but some parts of the world have had just a tiny fraction of our rates, with the highest rates reported in Connecticut, and the lowest in Kampala, Uganda. The famous surgeon Denis Burkitt spent 24 years in Uganda and most of the hospitals he contacted there had never seen a case of colon cancer. Noting they live off diets centered on whole plant foods, he figured that maybe it was the fiber that was so protective.

Some studies have called that interpretation into question. Danes appear to have more colon cancer than Finns, yet Danes consume almost twice the dietary fiber. What else, then, could explain the low cancer rates among plant-based populations? Well, fiber isn't the only thing found in whole plant foods, but missing from processed and animal foods. Maybe it's the phytate.

Dietary phytate, rather than fiber per se, may be the most important variable governing the frequency of colon cancer, as phytate is known to be a powerful inhibitor of the iron-mediated production of hydroxyl radicals, a particularly dangerous type of free radical. So the standard American diet may be a double whammy, the heme iron in muscle meat plus the lack of phytate in refined plant foods to extinguish the iron radicals.

This may account for what researchers found in the Adventist study, highlighted in my video, Phytates for the Prevention of Cancer. They found excess risk of cancer for higher intakes of both red meat and white meat, suggesting all meats contribute to colon cancer formation -- about twice the risk for red meat eaters, and three times the risk for those eating chicken and fish.

Those who eat meat could reduce their risk in two ways: by cutting down on meat or by eating more beans, an excellent source of phytates.

So it's not just how much meat we eat, but our meat to vegetables ratio. Between the two extremes (high-vegetable and low-meat diets versus high-meat and low-vegetable diets) a risk ratio of about eight appears to exist, sufficient to explain a substantial part of the international variation in the incidence of colorectal cancer. Those with the worst of both worlds, high meat and low vegetable, were at eight times the risk.

More on colon cancer in Stool Size Matters.

Here are a few of my latest videos on the latest wonders of the musical fruit:

What about that music, though? See my blog Beans and Gas: Clearing the air.

What about soybeans and cancer? See Breast Cancer Survival and Soy and BRCA Breast Cancer Genes and Soy.

Other ways to mediate the effects of meat intake can be found in my video Reducing Cancer Risk in Meateaters.

For more about how phytates may play a role in both cancer prevention and treatment see Phytates for Rehabilitating Cancer Cells and Phytates for the Treatment of Cancer.

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Ton Rulkens / Flickr

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Don’t Forget Fiber

NF-Feb17 Why We Shouldn't Forget About Fiber.jpg

The famous surgeon Denis Burkitt is better known for his discovery of a childhood cancer now known as Burkitt's lymphoma than for his 1979 international bestseller, Don't Forget the Fibre in Your Diet.

Anyone asked to list the twenty or more most important advances in health made in the last few decades would be likely to include none of what Dr. Burkitt considered to be among the most significant. What was the number one most important advance in health according to one of the most famous medical figures of the 20th century? The discovery that "Many of the major and commonest diseases in modern Western culture are universally rare in third-world communities, were uncommon even in the United States until after World War l" yet are now common in anyone following the Western lifestyle. So it's not genetics--they're lifestyle diseases (See Dr. Burkitt's F-Word Diet). This means they must potentially be preventable.

Those eating the standard American diet have very high levels of a long list of diseases--such as heart disease and colon cancer--that were similar to the rates of disease in the ruling white class in apartheid Africa. Conversely, the rates in the Bantu population were very low. These native Africans ate the same three sister diets of many Native Americans, a plant-based diet centered around corn, beans, and squash. In fact, it was reported that cancer was so seldom seen in American Indians a century ago they were considered practically immune to cancer--and heart disease. What are "very low" rates? 1300 Bantus were autopsied over five years in a Bantu hospital and maybe one case of ischemic heart disease, the West's number one killer.

The Bantu's rates of heart and intestinal disease is similar to poor Indians, whereas wealthier Indians who ate more animal and refined foods were closer to those in Japan--unless they moved to the U.S. and started living like us. You find similar trends for the other so-called Western diseases, which Burkitt thought were related to the major dietary changes that followed the lndustrial Revolution: a reduction in healthy whole plant foods--the source of starch and fiber-and a great increase in consumption of animal fats, salt, and sugar. His theory was that it was the fiber. He believed all of these major diseases may be caused by a diet deficient in whole plant foods, the only natural source of fiber.

Fiber? In a survey of 2,000 Americans, over 95% of graduate school-educated participants and health care providers weren't even aware of the daily recommended fiber intake. Doctors don't even know. How much fiber should we shoot for? The Institute of Medicine recommends 38 grams for men 50 years and younger and 30 grams for men over 50 years. Women 50 years and younger should get 25 and those older than 50 should get 21 grams. But these levels are just the minimum. I recommend we look to our evolutionary past for more clues on fiber intake. See my video Paleolithic Lessons.

One analogy Dr. Burkitt used is this: "If a floor is flooded as a result of a dripping tap, it is of little use to mop up the floor unless the tap is turned off. The water from the tap represents the cause of disease, the flooded floor the diseases filling our hospital beds. Medical students learn far more about methods of floor mopping than about turning off taps, and doctors who are specialists in mops and brushes can earn infinitely more than those dedicated to shutting off taps." And the drug companies is more than happy to sell us rolls of paper towels, so patients can buy a new roll every day for the rest of their lives. To paraphrase Ogden Nash: modern medicine is making great progress, but just headed in the wrong direction.

How do we know that diet was the critical factor? Because when we place people stricken with these diseases on plant-based diets, their disease can be reversed (Our Number One Killer Can Be Stopped). In fact it was the work of Burkitt and others in Africa that led to the disease reversal work of pioneers like Nathan Pritikin (Engineering a Cure).

More on fiber:

And for more of the scoop on poop:

-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 Uprooting the Leading Causes of Death, More Than an Apple a Day, and From Table to Able.

Image Credit: Rachel Hathaway / Flickr

Original Link