Plant versus Animal Iron

Plant versus Animal Iron.jpeg

It is commonly thought that those who eat plant-based diets may be more prone to iron deficiency, but it turns out that they're no more likely to suffer from iron deficiency anemia than anybody else. This may be because not only do those eating meat-free diets tend to get more fiber, magnesium, and vitamins like A, C, and E, but they also get more iron.

The iron found predominantly in plants is non-heme iron, which isn't absorbed as well as the heme iron found in blood and muscle, but this may be a good thing. As seen in my video, The Safety of Heme vs. Non-Heme Iron, avoidance of heme iron may be one of the key elements of plant-based protection against metabolic syndrome, and may also be beneficial in lowering the risk from other chronic diseases such as heart disease.

The data linking coronary heart disease and the intake of iron, in general, has been mixed. This inconsistency of evidence may be because of where the iron comes from. The majority of total dietary iron is non-heme iron, coming mostly from plants. So, total iron intake is associated with lower heart disease risk, but iron intake from meat is associated with significantly higher risk for heart disease. This is thought to be because iron can act as a pro-oxidant, contributing to the development of atherosclerosis by oxidizing cholesterol with free radicals. The risk has been quantified as a 27% increase in coronary heart disease risk for every 1 milligram of heme iron consumed daily.

The same has been found for stroke risk. The studies on iron intake and stroke have had conflicting results, but that may be because they had never separated out heme iron from non-heme iron... until now. Researchers found that the intake of meat (heme) iron, but not plant (non-heme) iron, was associated with an increased risk of stroke.

The researchers also found that higher intake of heme iron--but not total or plant (non-heme) iron--was significantly associated with greater risk for type 2 diabetes. There may be a 16% increase in risk for type 2 diabetes for every 1 milligram of heme iron consumed daily.

The same has also been found for cancer, with up to 12% increased risk for every milligram of daily heme iron exposure. In fact, we can actually tell how much meat someone is eating by looking at their tumors. To characterize the mechanisms underlying meat-related lung cancer development, researchers asked lung cancer patients how much meat they ate and examined the gene expression patterns in their tumors. They identified a signature pattern of heme-related gene expression. Although they looked specifically at lung cancer, they expect these meat-related gene expression changes may occur in other cancers as well.

We do need to get enough iron, but only about 3% of premenopausal white women have iron deficiency anemia these days. However, the rates are worse in African and Mexican Americans. Taking into account our leading killers--heart disease, cancer, and diabetes--the healthiest source of iron appears to be non-heme iron, found naturally in abundance in whole grains, beans, split peas, chickpeas, lentils, dark green leafy vegetables, dried fruits, nuts, and seeds.

But how much money can be made on beans, though? The processed food industry came up with a blood-based crisp bread, made out of rye flour and blood from cattle and pigs, which is one of the most concentrated sources of heme iron, about two-thirds more than blood from chickens. If blood-based crackers don't sound particularly appetizing, you can always snack on cow blood cookies. And there are always blood-filled biscuits, whose filling has been described as "a dark-colored, chocolate flavored paste with a very pleasant taste." (It's dark-colored because spray-dried pig blood can have a darkening effect on the food product's color.) The worry is not the color or taste, it's the heme iron, which, because of its potential cancer risk, is not considered safe to add to foods intended for the general population.

Previously, I've touched on the double-edged iron sword in Risk Associated With Iron Supplements and Phytates for the Prevention of Cancer. It may also help answer Why Was Heart Disease Rare in the Mediterranean?

Those eating plant-based diets get more of most nutrients since whole plant foods are so nutrient dense. See Nutrient-Dense Approach to Weight Management.

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

Plant versus Animal Iron

Plant versus Animal Iron.jpeg

It is commonly thought that those who eat plant-based diets may be more prone to iron deficiency, but it turns out that they're no more likely to suffer from iron deficiency anemia than anybody else. This may be because not only do those eating meat-free diets tend to get more fiber, magnesium, and vitamins like A, C, and E, but they also get more iron.

The iron found predominantly in plants is non-heme iron, which isn't absorbed as well as the heme iron found in blood and muscle, but this may be a good thing. As seen in my video, The Safety of Heme vs. Non-Heme Iron, avoidance of heme iron may be one of the key elements of plant-based protection against metabolic syndrome, and may also be beneficial in lowering the risk from other chronic diseases such as heart disease.

The data linking coronary heart disease and the intake of iron, in general, has been mixed. This inconsistency of evidence may be because of where the iron comes from. The majority of total dietary iron is non-heme iron, coming mostly from plants. So, total iron intake is associated with lower heart disease risk, but iron intake from meat is associated with significantly higher risk for heart disease. This is thought to be because iron can act as a pro-oxidant, contributing to the development of atherosclerosis by oxidizing cholesterol with free radicals. The risk has been quantified as a 27% increase in coronary heart disease risk for every 1 milligram of heme iron consumed daily.

The same has been found for stroke risk. The studies on iron intake and stroke have had conflicting results, but that may be because they had never separated out heme iron from non-heme iron... until now. Researchers found that the intake of meat (heme) iron, but not plant (non-heme) iron, was associated with an increased risk of stroke.

The researchers also found that higher intake of heme iron--but not total or plant (non-heme) iron--was significantly associated with greater risk for type 2 diabetes. There may be a 16% increase in risk for type 2 diabetes for every 1 milligram of heme iron consumed daily.

The same has also been found for cancer, with up to 12% increased risk for every milligram of daily heme iron exposure. In fact, we can actually tell how much meat someone is eating by looking at their tumors. To characterize the mechanisms underlying meat-related lung cancer development, researchers asked lung cancer patients how much meat they ate and examined the gene expression patterns in their tumors. They identified a signature pattern of heme-related gene expression. Although they looked specifically at lung cancer, they expect these meat-related gene expression changes may occur in other cancers as well.

We do need to get enough iron, but only about 3% of premenopausal white women have iron deficiency anemia these days. However, the rates are worse in African and Mexican Americans. Taking into account our leading killers--heart disease, cancer, and diabetes--the healthiest source of iron appears to be non-heme iron, found naturally in abundance in whole grains, beans, split peas, chickpeas, lentils, dark green leafy vegetables, dried fruits, nuts, and seeds.

But how much money can be made on beans, though? The processed food industry came up with a blood-based crisp bread, made out of rye flour and blood from cattle and pigs, which is one of the most concentrated sources of heme iron, about two-thirds more than blood from chickens. If blood-based crackers don't sound particularly appetizing, you can always snack on cow blood cookies. And there are always blood-filled biscuits, whose filling has been described as "a dark-colored, chocolate flavored paste with a very pleasant taste." (It's dark-colored because spray-dried pig blood can have a darkening effect on the food product's color.) The worry is not the color or taste, it's the heme iron, which, because of its potential cancer risk, is not considered safe to add to foods intended for the general population.

Previously, I've touched on the double-edged iron sword in Risk Associated With Iron Supplements and Phytates for the Prevention of Cancer. It may also help answer Why Was Heart Disease Rare in the Mediterranean?

Those eating plant-based diets get more of most nutrients since whole plant foods are so nutrient dense. See Nutrient-Dense Approach to Weight Management.

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

Can Oatmeal Reverse Heart Disease?

Can Oatmeal Reverse Heart Disease?.jpeg

Fiber continues to be singled out as a nutrient of public health concern. We're getting only about half the minimum recommended intake on average. There is a fiber gap in America. Less than 3 percent meet the recommended minimum. This means that less than 3 percent of all Americans eat enough whole plant foods, the only place fiber is found in abundance. If even half of the adult population ate 3 more grams a day--a quarter cup of beans or a bowl of oatmeal--we could potentially save billions in medical costs. And that's just for constipation! The consumption of plant foods, of fiber-containing foods, may reduce the risk for diabetes, heart disease, stroke, cancer, and obesity as well.

The first to make this link between fiber intake and killer disease was probably Dr. Hugh Trowell. He spent 30 years practicing medicine in Africa and suspected it was the Africans high consumption of corn, millet, sweet potatoes, greens, and beans that protected them from chronic disease. This twisted into the so-called "fiber hypothesis," but Trowell didn't think it was the fiber itself, but the high-fiber foods themselves that were protective. There are hundreds of different substances in whole plant foods besides fiber that may have beneficial effects. For example, the fiber in oatmeal can lower our blood cholesterol levels so that less gets stuck in our arteries, but there also are anti-inflammatory and antioxidant phytonutrients in oats that can prevent atherosclerotic build-up and then help maintain arterial function (see Can Oatmeal Reverse Heart Disease?).

Visionaries like Trowell were not entrapped by the reductionist "simple-minded" focus on dietary fiber and insisted that the whole plant foods should receive the emphasis. Fiber intake was just a marker for plant food intake. Those with the highest fiber intake and the lowest cholesterol were those whose who ate exclusively plant-based diets.

Risk factors like cholesterol are one thing, but can these individual foods actually affect the progression of heart disease, the #1 killer of Americans? We didn't know until 2005. Hundreds of older women were subjected to coronary angiograms, where we inject dye into the coronary arteries of the heart to see how wide open they are. Each participant got an angiogram at the beginning of the study and one a few years later, all while researchers analyzed their diets. The arteries of women eating less than a serving of whole grains a day significantly narrowed, whereas the arteries of women who ate just a single serving or more also significantly narrowed, but they narrowed less. These were all women with heart disease eating the standard American diet, so their arteries were progressively clogging shut. But there was significantly less clogging in the women eating more whole grains, significantly less progression of their atherosclerosis. A similar slowing of their disease might be expected from taking cholesterol-lowering statin drugs. But do we want to just slow the rate at which we die from heart disease, or do we want to not die from heart disease at all?

A strictly plant-based diet has been shown to reverse the progression of heart disease, opening up arteries back up. Yes, whole grains, like drugs, can help counter the artery-clogging effects of the rest of the diet. Having oatmeal with bacon and eggs is better than just eating bacon and eggs, but why not stop eating an artery-clogging diet altogether?

Oatmeal offers a lot more than fiber, though. See Oatmeal Lotion for Chemotherapy-Induced Rash and Can Oatmeal Help Fatty Liver Disease?

Trowell's work had a big influence on Dr. Denis Burkitt. See Dr. Burkitt's F-Word Diet.

This reminds me of other interventions like hibiscus tea for high blood pressure (Hibiscus Tea vs. Plant-Based Diets for Hypertension) or amla for diabetes (Amla Versus Diabetes). Better to reverse the disease completely.

And for an overview of how whole plant foods affect disease risks, be sure to check out the videos on our new Introduction page!

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: Rachel Hathaway / Flickr. This image has been modified.

Original Link

Can Oatmeal Reverse Heart Disease?

Can Oatmeal Reverse Heart Disease?.jpeg

Fiber continues to be singled out as a nutrient of public health concern. We're getting only about half the minimum recommended intake on average. There is a fiber gap in America. Less than 3 percent meet the recommended minimum. This means that less than 3 percent of all Americans eat enough whole plant foods, the only place fiber is found in abundance. If even half of the adult population ate 3 more grams a day--a quarter cup of beans or a bowl of oatmeal--we could potentially save billions in medical costs. And that's just for constipation! The consumption of plant foods, of fiber-containing foods, may reduce the risk for diabetes, heart disease, stroke, cancer, and obesity as well.

The first to make this link between fiber intake and killer disease was probably Dr. Hugh Trowell. He spent 30 years practicing medicine in Africa and suspected it was the Africans high consumption of corn, millet, sweet potatoes, greens, and beans that protected them from chronic disease. This twisted into the so-called "fiber hypothesis," but Trowell didn't think it was the fiber itself, but the high-fiber foods themselves that were protective. There are hundreds of different substances in whole plant foods besides fiber that may have beneficial effects. For example, the fiber in oatmeal can lower our blood cholesterol levels so that less gets stuck in our arteries, but there also are anti-inflammatory and antioxidant phytonutrients in oats that can prevent atherosclerotic build-up and then help maintain arterial function (see Can Oatmeal Reverse Heart Disease?).

Visionaries like Trowell were not entrapped by the reductionist "simple-minded" focus on dietary fiber and insisted that the whole plant foods should receive the emphasis. Fiber intake was just a marker for plant food intake. Those with the highest fiber intake and the lowest cholesterol were those whose who ate exclusively plant-based diets.

Risk factors like cholesterol are one thing, but can these individual foods actually affect the progression of heart disease, the #1 killer of Americans? We didn't know until 2005. Hundreds of older women were subjected to coronary angiograms, where we inject dye into the coronary arteries of the heart to see how wide open they are. Each participant got an angiogram at the beginning of the study and one a few years later, all while researchers analyzed their diets. The arteries of women eating less than a serving of whole grains a day significantly narrowed, whereas the arteries of women who ate just a single serving or more also significantly narrowed, but they narrowed less. These were all women with heart disease eating the standard American diet, so their arteries were progressively clogging shut. But there was significantly less clogging in the women eating more whole grains, significantly less progression of their atherosclerosis. A similar slowing of their disease might be expected from taking cholesterol-lowering statin drugs. But do we want to just slow the rate at which we die from heart disease, or do we want to not die from heart disease at all?

A strictly plant-based diet has been shown to reverse the progression of heart disease, opening up arteries back up. Yes, whole grains, like drugs, can help counter the artery-clogging effects of the rest of the diet. Having oatmeal with bacon and eggs is better than just eating bacon and eggs, but why not stop eating an artery-clogging diet altogether?

Oatmeal offers a lot more than fiber, though. See Oatmeal Lotion for Chemotherapy-Induced Rash and Can Oatmeal Help Fatty Liver Disease?

Trowell's work had a big influence on Dr. Denis Burkitt. See Dr. Burkitt's F-Word Diet.

This reminds me of other interventions like hibiscus tea for high blood pressure (Hibiscus Tea vs. Plant-Based Diets for Hypertension) or amla for diabetes (Amla Versus Diabetes). Better to reverse the disease completely.

And for an overview of how whole plant foods affect disease risks, be sure to check out the videos on our new Introduction page!

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: Rachel Hathaway / Flickr. This image has been modified.

Original Link

High Blood Pressure: Normal but Not Natural

High Blood Pressure - Normal but Not Natural.jpeg

The most comprehensive and systematic analysis of causes of death ever undertaken allows us to answer questions like, how many lives could we save if people cut back on soda? The answer is 299,521. Soft drinks aren't just bad because they're empty calories. More than just not being a health-promoting item, soda appears to be an actively death-promoting item. Of course, it's not as deadly as processed meats such as bacon, bologna, ham, or hot dogs, which account for about 800,000 deaths every year--killing twice as many women as domestic violence and five times more people than all illegal drugs combined.

On the other hand, eating more whole grains could save 1.7 million lives. And more vegetables could save 1.8 million lives every year. If only we ate more nuts and seeds, we'd save 2 and a half million lives. But fruit is apparently what the world needs most (they didn't look at beans) with 4.9 million lives hanging in the balance every year. The cure is not drugs or vaccines; the cure is fruit. The #1 dietary risk factor for death in the world may be not eating enough fruit.

One reason why plant-based diets can save so many millions is because the #1 killer risk factor in the world is high blood pressure, laying to waste nine million people year after year. In the United States, high blood pressure affects nearly 78 million--that's one in three of us. As we age our pressures get higher and higher, such that by age 60, it strikes more than half of that population. If it affects most of us when we get older, maybe it's less a disease and more just a natural, inevitable consequence of getting older?

No.

We've known for nearly a century that high blood pressure need never occur. Researchers measured the blood pressure of a thousand people in rural Kenya. Up until age 40, the blood pressures of rural Africans were about the same as Europeans and Americans, down around 120's over 80's, but as Westerners age, our pressures creep up such that by age 60 the average person is hypertensive, exceeding 140 over 90. But the pressures of those in rural Africa improved with age; not only did they not develop hypertension, their blood pressures actually got better.

The 140/90 cut-off is arbitrary. Just like studies that show the lower our cholesterol the better--there's really no safe level above about 150--blood pressure studies also support a "lower the better" approach. Even people who start out with blood pressure under 120/80 appear to benefit from blood pressure reduction. The ideal blood pressure, the no-benefit-from-reducing-it-further blood pressure, appears to be 110/70. Is it possible to get blood pressures under 110 over 70? It's not just possible, it can be normal for those eating healthy enough diets (see How Not to Die from High Blood Pressure).

Over two years at a rural Kenyan hospital, 1,800 patients were admitted. How many cases of high blood pressure were found? Zero. Wow. They must have had low rates of heart disease. Actually, they had no rates of heart disease. Not low risk--no risk. Not a single case of arteriosclerosis was found.

Having a "normal" blood pressure may set you up for dying from "normal" causes such as heart attacks and strokes. For more on this concept, see When Low Risk Means High Risk. It's like having a normal cholesterol level (see Optimal Cholesterol Level).

It seems high blood pressure is a choice. Like cavities: Cavities and Coronaries: Our Choice.

Even end-stage malignant hypertension can be reversed with diet (thereby demonstrating it was the diet and not other lifestyle factors that protected traditional plant-based populations). See Kempner Rice Diet: Whipping Us Into Shape.

Flax seeds, hibiscus tea, whole grains, and nitrate-rich vegetables may offer additional protection:

Why not just take the drugs? See The Actual Benefit of Diet vs. Drugs and Why Prevention is Worth a Ton of Cure. And be sure to check out my summary video, How Not to Die from High Blood Pressure, as well as The Evidence that Salt Raises Blood Pressure.

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

High Blood Pressure: Normal but Not Natural

High Blood Pressure - Normal but Not Natural.jpeg

The most comprehensive and systematic analysis of causes of death ever undertaken allows us to answer questions like, how many lives could we save if people cut back on soda? The answer is 299,521. Soft drinks aren't just bad because they're empty calories. More than just not being a health-promoting item, soda appears to be an actively death-promoting item. Of course, it's not as deadly as processed meats such as bacon, bologna, ham, or hot dogs, which account for about 800,000 deaths every year--killing twice as many women as domestic violence and five times more people than all illegal drugs combined.

On the other hand, eating more whole grains could save 1.7 million lives. And more vegetables could save 1.8 million lives every year. If only we ate more nuts and seeds, we'd save 2 and a half million lives. But fruit is apparently what the world needs most (they didn't look at beans) with 4.9 million lives hanging in the balance every year. The cure is not drugs or vaccines; the cure is fruit. The #1 dietary risk factor for death in the world may be not eating enough fruit.

One reason why plant-based diets can save so many millions is because the #1 killer risk factor in the world is high blood pressure, laying to waste nine million people year after year. In the United States, high blood pressure affects nearly 78 million--that's one in three of us. As we age our pressures get higher and higher, such that by age 60, it strikes more than half of that population. If it affects most of us when we get older, maybe it's less a disease and more just a natural, inevitable consequence of getting older?

No.

We've known for nearly a century that high blood pressure need never occur. Researchers measured the blood pressure of a thousand people in rural Kenya. Up until age 40, the blood pressures of rural Africans were about the same as Europeans and Americans, down around 120's over 80's, but as Westerners age, our pressures creep up such that by age 60 the average person is hypertensive, exceeding 140 over 90. But the pressures of those in rural Africa improved with age; not only did they not develop hypertension, their blood pressures actually got better.

The 140/90 cut-off is arbitrary. Just like studies that show the lower our cholesterol the better--there's really no safe level above about 150--blood pressure studies also support a "lower the better" approach. Even people who start out with blood pressure under 120/80 appear to benefit from blood pressure reduction. The ideal blood pressure, the no-benefit-from-reducing-it-further blood pressure, appears to be 110/70. Is it possible to get blood pressures under 110 over 70? It's not just possible, it can be normal for those eating healthy enough diets (see How Not to Die from High Blood Pressure).

Over two years at a rural Kenyan hospital, 1,800 patients were admitted. How many cases of high blood pressure were found? Zero. Wow. They must have had low rates of heart disease. Actually, they had no rates of heart disease. Not low risk--no risk. Not a single case of arteriosclerosis was found.

Having a "normal" blood pressure may set you up for dying from "normal" causes such as heart attacks and strokes. For more on this concept, see When Low Risk Means High Risk. It's like having a normal cholesterol level (see Optimal Cholesterol Level).

It seems high blood pressure is a choice. Like cavities: Cavities and Coronaries: Our Choice.

Even end-stage malignant hypertension can be reversed with diet (thereby demonstrating it was the diet and not other lifestyle factors that protected traditional plant-based populations). See Kempner Rice Diet: Whipping Us Into Shape.

Flax seeds, hibiscus tea, whole grains, and nitrate-rich vegetables may offer additional protection:

Why not just take the drugs? See The Actual Benefit of Diet vs. Drugs and Why Prevention is Worth a Ton of Cure. And be sure to check out my summary video, How Not to Die from High Blood Pressure, as well as The Evidence that Salt Raises Blood Pressure.

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

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.

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Benefits of Oatmeal for Fatty Liver Disease

Benefits of Oatmeal for Fatty Liver Disease.jpeg

If oatmeal is so powerful that it can clear up some of the ravages of chemotherapy just applied to the skin (see my video Oatmeal Lotion for Chemotherapy-Induced Rash), what might it do if we actually ate it? Oats are reported to possess varied drug-like activities like lowering blood cholesterol and blood sugar, boosting our immune system, anticancer, antioxidant, and anti-atherosclerosis activites, in addition to being a topical anti-inflammatory, and reprtedly may also be useful in controlling childhood asthma and body weight.

Whole-grain intake in general is associated with lower risk of type 2 diabetes, cardiovascular disease, and weight gain, as shown in my video Can Oatmeal Help Fatty Liver Disease?. All of the cohort studies on type 2 diabetes and heart disease show whole grain intake is associated with lower risk.

Researchers have observed the same for obesity--consistently less weight gain for those who consumed a few servings of whole grains every day. All the forward-looking population studies demonstrate that a higher intake of whole grains is associated with lower body mass index and body weight gain. However, these results do not clarify whether whole grain consumption is simply a marker of a healthier lifestyle or a factor favoring lower body weight.

For example, high whole grain consumers--those who eat whole wheat, brown rice, and oatmeal for breakfast--tend to be more physically active, smoke less, and consume more fruit, vegetables, and dietary fiber than those that instead reach for fruit loops. Statistically, one can control these factors, effectively comparing nonsmokers to nonsmokers with similar exercise and diet as most of the studies did, and they still found whole grains to be protective via a variety of mechanisms.

For example, in terms of helping with weight control, the soluble fiber of oatmeal forms a gel in the stomach, delaying stomach emptying, making one feel full for a longer period. It seems plausible that whole grain intake does indeed offer direct benefits, but only results of randomized controlled intervention studies can provide direct evidence of cause and effect. In other words, the evidence is clear that oatmeal consumers have lower rates of disease, but that's not the same as proving that if we start eating more oatmeal, our risk will drop. To know that, we need an interventional trial, ideally a blinded study where you give half the people oatmeal, and the other half fake placebo oatmeal that looks and tastes like oatmeal, to see if it actually works. And that's what we finally got--a double-blinded randomized trial of overweight and obese men and women. Almost 90% of the real oatmeal-treated subjects had reduced body weight, compared to no weight loss in the control group. They saw a slimmer waist on average, a 20 point drop in cholesterol, and an improvement in liver function.

Nonalcoholic fatty liver disease, meaning a fatty liver caused by excess food rather than excess drink, is now the most common cause of liver disease in the United States, and can lead in rare cases to cirrhosis of the liver, cancer of the liver, and death. Theoretically, whole grains could help prevent and treat fatty liver disease, but this is the first time it had been put to the test. A follow-up study in 2014 confirmed these findings of a protective role of whole grains, but refined grains was associated with increased risk. So one would not expect to get such wonderful results from wonder bread.

How can you make your oatmeal even healthier? See Antioxidants in a Pinch.

Whole Grains May Work As Well As Drugs for hypertension, but refined grain intake may linked with high blood pressure and diseases like diabetes. But If White Rice is Linked to Diabetes, What About China?.

More on keeping the liver healthy in videos like:

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