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

Is it Better to Bake, Boil, or Steam Sweet Potatoes?

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I previously talked about the cancer fighting properties of sweet potatoes (See Anti-Cancer Potential of Sweet Potato Proteins) and what would happen if you centered your diet around them (The Okinawa Diet: Living to 100). It seems that the only potential downside to eating too many sweet potatoes is that you could get yellow palms (or nose as you can see in the video, The Best Way to Cook Sweet Potatoes), a harmless condition called "carotenemia." Caused by elevated levels of beta carotene in the blood, it was first noticed a century ago when carrots were introduce into infant diets. It's treated mostly by just reassuring parents that it's harmless, but if we don't want our child's nose to be yellow, we can decrease their beta carotene intake and in a few months it will be gone.

When picking out varieties at the supermarket, the intensity of the yellow or orange flesh color of the sweet potato is directly correlated to its nutritional content, so the more intense the better. Though if you really want intensity, sweet potato varieties don't just range from white to yellow and orange, but from pink to deep purple. The natural pigments that cause these colors may have special anticancer effects.

What is the best way to cook sweet potatoes? Boiling may actually retain most of the antioxidant power of sweet potatoes, compared to roasting and steaming. If we compare baking to boiling microscopically, boiling helps thin out the cell walls and gelatinize the starch, which may enhance the bioavailability of nutrients. At the same time, the glycemic index of boiled sweet potatoes was found to be about half that of baking or roasting, so boiled sweet potatoes give us less of a blood sugar spike.

Make sure to keep the skin on, though. The peel of a sweet potato has nearly ten times the antioxidant power as the flesh (an antioxidant capacity comparable to that of blueberries). However, the peel's nutrition really takes a hit when baked, which wipes out over two thirds of the antioxidants, whereas microwaving or boiling are comparatively much gentler. The same is true for the rest of the sweet potato. Baking can also cause an 80% drop in vitamin A levels, twice as much as boiling. Therefore, from a nutritional standpoint, boiling rather than baking should be recommended for cooking sweet potato.

Boiling may theoretically be best, but sweet potatoes are so incredibly healthy that the actual best way to prepare them is whichever way will get you to eat the most of them! The exception is deep frying, which can lead to the formation of acrylamide, a potential human carcinogen.

What about cooking methods for other vegetables? See my video Best Cooking Method.

Want more information about acrylamide, the potential crispy carb carcinogen? See my video Cancer Risk from French Fries. And for why deep frying in general might not be good, Deep Frying Toxins and Carcinogens in the Smell of Frying Bacon.

-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: Avital Pinnick / Flickr

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Sweet Potato Proteins vs. Cancer

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Sweet potatoes can be considered a superfood. They are one of the healthiest and cheapest vegetables on the planet. (And one day, perhaps, even off the planet, as NASA has chosen the sweet potato for space missions.) A study out of the University of Washington aimed to identify which vegetables provided the most nutrients per dollar. In my video, Anti-Cancer Potential of Sweet Potato Proteins, you can see a graph of affordability versus nutrition for different foods. The healthiest foods, like dark green leafy vegetables, may also be the cheapest, and the highest nutrient-rich food scores per dollar were obtained for sweet potatoes.

Sweet potatoes are not just packed with nutrition but may also have special cancer-fighting properties. In 1931, a unique protein was discovered in sweet potatoes. It turns out that 80% of the protein in sweet potatoes is a type of protease inhibitor with potential anticancer effects. These proteins were originally tested against leukemia and appeared to suppress the growth of leukemia cells in a petri dish.

But how would a sweet potato protein ever get into our bloodstream? As soon as most proteins hit our stomach, they start getting digested. To get around the digestion issue, researchers tried sweet potato protein against tongue cancer cells (sweet potato proteins certainly come in contact with our mouth!). Tongue cancer is often treated with chemotherapy, and most of the chemo drugs for tongue cancer have adverse effects, so it is indispensable for us to find other therapeutic strategies. Sweet potato protein rapidly diminished viability of the cancer in vitro within a matter of days, leading the researchers to propose that sweet potatoes may be useful for human tongue cancer. But could they possibly help with other cancers as well?

Remarkably, this special class of proteins doesn't just survive digestion, but may also be absorbed into the bloodstream intact (in at least two of the nine women with advanced cervical cancer researchers tried giving them to).

Most recently, sweet potato proteins were tried on colorectal cancer cells, one of our most common and deadly cancers. Normally we just surgically remove the colon, but that only works in the early stages since there are often "micrometastases" outside the colon that can subsequently lead to cancer recurrence and death, so we've been searching for anti-metastatic agents. Not only does sweet potato protein slow down the growth of colon cancer cells, but it may also decrease cancer cell migration and invasion.

Sweet potato consumption has also been associated with lower gallbladder cancer rates, but it has never been directly put to the test, but what's the downside?

Sweet potatoes are one of my favorite snacks. During the harsh Boston winters during my medical training, I used to put two freshly microwaved sweet potatoes in my coat pockets as natural hand-warmers. When they cooled down, my hand-warmers became instant healthy snacks!

More videos on getting the most nutrition for one's dollar:

What other vegetables might contain cancer fighting properties? See #1 AntiCancer Vegetable.

Are sweet potatoes best steamed? Should we eat the skin? Find out in my video: Best Way to Cook Sweet Potatoes.

-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: thebittenword.com / Flickr

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Why Deep Fried Foods May Cause Cancer

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In the latest study on dietary patterns and breast cancer risk among women, healthier eating was associated with eliminating three-quarters of the odds of breast cancer, whereas less healthy eating was associated with up to nearly eight times the odds. Included in the unhealthy eating pattern was the consumption of deep-fried foods, which have previously been linked to breast cancer, pancreatic cancer, lung cancer, oral and throat cancers, esophageal cancer, and cancer of the voicebox. No deep fried foods? What's a Southern belle to do? Instead of deep fried foods, how about the traditional Southern diet, characterized by high intakes of cooked greens, beans, legumes, cabbage, sweet potatoes and cornbread, which may reduce the risk of invasive breast cancer significantly.

What about the consumption of deep-fried foods and risk of prostate cancer? Researchers at the Fred Hutchinson Cancer Research Center and the University of Washington found that eating French fries, fried chicken, fried fish, and doughnuts was associated with about a third greater odds of prostate cancer. After stratifying for tumor aggressiveness, they found slightly stronger associations with more aggressive disease, suggesting that regular intake of deep-fried foods may contribute to the progression of prostate cancer as well.

What in deep fried foods is so bad for us? Just heating oil that hot can generate potentially carcinogenic compounds, and then known carcinogens such as heterocyclic amines and polycyclic aromatic hydrocarbons form when the muscles of chickens and fish are cooked at that temperature. Deep-fried plants, on the other hand, can form acrylamide.

I did a video about acrylamide back in 2008, suggesting it's a probable human carcinogen (See Acrylamide in French Fries). Since then, studies have suggested pregnant women may want to cut back on French fries to protect the growth of their baby's body and brain. Based on a study (highlighted in my video, Cancer Risk from French Fries) feeding people a little bag of potato chips every day for a month, it now seems acrylamide may also cause inflammation as well, which could explain its purported role in cancer progression.

Acrylamide intake has been associated with endometrial cancer, ovarian cancer, lung cancer, kidney cancer, and esophageal cancer. How much cancer risk are we talking about? Taiwanese researchers examined lifetime cancer risk and French fry consumption. The researchers picked on French fries because they comprise by far the greatest percentage contribution of acrylamide to the diets of children. They estimated that, at most, one or two boys and girls out of every ten thousand would develop cancer eating French fries that they would otherwise not have developed if they hadn't eaten French fries. So it's not as bad as eating something like fried fish, or fried chicken, but how much is that saying?

The level of cancer risk in both boys and girls associated with French fries depends on how long and hot they're fried. In Europe, the food industry swore that they'd self-regulate and control fry times to decrease acrylamide levels, but we've yet to see any subsequent change in acrylamide levels in French fries.

Researchers continue to urge that the cooking temperature should be as low as possible and the cooking time should be as short as possible, "while still maintaining a tasty quality" of course. We wouldn't want to reduce cancer risk too much--they might not taste as good!

Blanching the potatoes first reduces acrylamide formation, but potato chip companies complain that, not only would it muck with the flavor, but it would reduce the nutritional properties by leaching away some of the vitamin C. But if we're relying on potato chips to get our vitamin C, acrylamide is probably the least of our worries.

More on heterocyclic amines:

There are some things we can do to counteract the effects of these carcinogens, though:

I touch on polycyclic aromatic hydrocarbons in Meat Fumes: Dietary Secondhand Smoke and Is Liquid Smoke Flavoring Carcinogenic?
Certain fats may play a role in breast cancer survival as well: Breast Cancer Survival, Butterfat, and Chicken and Breast Cancer Survival and Trans Fat.

-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: Kim Love / Flickr

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