Tree Nuts or Peanuts for Breast Cancer Prevention?

Tree Nuts or Peanuts For Breast Cancer Prevention?By: Micheal Greger, MD, Director of Public Health and Animal Agriculture at the Humane Society of the United States.

That Black Women’s Health Study, which highlighted collards and carrots, was out of Boston University. Across the Charles River, the Harvard Nurse’s Health Study also tried to determine which plants were particularly protective in reducing breast cancer risk, and they identified nuts.

The intake of fiber and nuts during adolescence and incidence of proliferative benign breast disease, such as fibrocystic breast disease, fibroadenomas—noncancerous breast lumps—but is considered a marker for increased breast cancer risk. Depending on what biopsies show it could indicate anywhere from 30% to 1300% greater risk of going on to develop cancer.

Breast cancer can take decades to develop, so they wanted to start early, asking women what their diets were like in high school. Now in adults it’s clear, as you can see in this 2012 review, the more fiber you get in your diet the lower your risk of breast cancer… And same thing, apparently, when you’re younger. Women who had the most fiber intake during adolescence have a 25% lower risk of this potentially precancerous breast disease. But there’s fiber in fruits, vegetables, beans, whole grains, nuts, seeds—all whole plant foods.

Did any class of plant foods stick out? Nuts was found to be particularly protective. Two servings a week was associated with a 36% lower risk, but that raises the question, which type of nuts? Like peanut butter and jelly sandwiches or do you have to eat true nuts, like almonds, pecans, walnuts, that sort of thing. Just tree nuts, or peanuts as well? And the answer is both. Compared to those who rarely ate nuts, those eating just one or two handfuls a week during high school appeared to drop risk around 30%,

In summary, their study observed significant inverse associations between adolescent dietary intake of fiber and nuts and risk of proliferative benign breast disease. Our results provide supportive evidence of the important role of dietary exposures during a unique period in a woman’s life in the earlier stage of breast carcinogenesis, the early stage of breast cancer development. These findings, if corroborated, may suggest a viable means for breast cancer prevention.”

Doctor’s Note

Harvard also found that fiber and nut consumption was associated with a significantly longer lifespan in women. See What Women Should Eat to Live Longer. Soy consumption during adolescence also seems particularly protective. See Thursday’s video Why Do Asian Women Have Less Breast Cancer?. The reference to the Black Women’s Health Study was referring to Friday’s video-of-the-day Preventing Breast Cancer By Any Greens Necessary. What effect might even just a few weeks on a diet full of plants have on breast cancer cell growth? See Answer to the Pritikin Puzzle. Don’t nuts make you fat, though? You’d be surprised—see Nuts and Obesity: The Weight of Evidence.

Please also check out my associated blog posts  for more context:  Go Nuts for Breast Cancer Prevention and Breast Cancer & Alcohol: How Much Is Safe?

Michael Greger M.D.About Michael Greger M.D.Michael Greger, M.D., is a physician, author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United States.

Photo Source: NutritionFacts.org

Which Nut Fights Cancer Better?

Walnuts for Breast Cancer PreventionBy: Dr. Michael Greger, Director of Public Health and Animal Agriculture at the Humane Society of the United States.

In my video on nuts and breast cancer prevention, I featured data from the Harvard Nurse’s Study suggesting early nut consumption may be a viable means for breast cancer prevention. A follow-up study involving the daughters of the nurses corroborated the findings. Those eating more peanut butter, nuts, beans, lentils, soybeans or corn were found to just have a fraction of the risk for fibrocystic breast disease, which places one at higher risk of cancer, and the protective effects were found to be strongest for those most at risk, the ones with a family history of breast cancer.

A new study even found two handfuls of nuts a week may protect against pancreatic cancer, one of our most fatal malignancies. We’re not sure why they work. Nuts are described as nutritionally precious, packed with all sorts of goodies, which may explain some of the mechanisms by which nut components induce cancer cell death, and inhibit cancer growth and spread in vitro, but which nuts work the best?

In my video #1 Anticancer vegetable we learned that two classes of vegetables, the broccoli family vegetables, and the garlic family vegetables most effectively suppressed breast cancer cell growth.

Then in Which Fruit Fights Cancer Better? Cranberries and lemons took the title.

What about nuts? In terms of antioxidant content, walnuts and pecans steal the show. Twenty-five walnuts have the antioxidant equivalent of eight grams of vitamin C, that’s like the vitamin C found in a hundred oranges. Ah, but how do they do against cancer?

Here is a graph of human cancer cell proliferation versus increasing concentrations of the ten most common nuts eaten in the United States. If you drip water on these cancer cells as a control, nothing happens. They start out powering away at 100% growth and they keep powering away at 100% growth. And hazelnuts, pistachios and brazil nuts don’t do much better.

Pine nuts, cashews, and macadamias start pulling away from the pack. Almonds appear twice as protective, halving cancer cell growth at only half the dose, but these three are the winners, causing a dramatic drop in cancer proliferation at just tiny doses: walnuts and pecans, with the bronze going to peanuts. This was nuts versus human liver cancer cells, like they did in the fruit study.

They found similar results pitting nuts against human colon cancer cells, which is particularly useful, since ingested nuts would come in direct contact with colon cancer tumors in the real world, whereas for something like breast cancer, even if nuts suppressed breast cancer cell growth in a petri dish, that doesn’t necessarily mean nut consumption would suppress breast tumor growth, since the protective nut compounds might not even get absorbed into the bloodstream.

To test that you’d have to like design an experiment where you drip the blood of nut-eaters versus non-nut eaters on breast cancer, and that’s exactly what researchers a Penn State recently did. And they wanted to know what it was about nuts that was so protective, so they fed people whole walnuts, just the walnut oil, or just the walnut skins, and then over the next six hours dripped their blood on human breast cancer cells in a petri dish, and the blood of those eating walnuts suppressed the growth of human breast cancer, but just the oil or just the skin didn’t work.

These data suggest that some components of walnuts are absorbed, circulate in the blood and affect either directly or indirectly breast cancer cell proliferation.

Michael Greger M.D.About Michael Greger M.D.
Michael Greger, M.D., is a physician, author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous “meat defamation” trial. Currently Dr. Greger proudly serves as the Director of Public Health and Animal Agriculture at the Humane Society of the United States.

Photo Source: http://www.Walnuts.org

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