Sharon B. Salomon, M.S., R.D.

Studies indicate regular exercise might reduce the risk of developing breast cancer

Let's face it. The statistics for breast cancer are alarming. The American Cancer Society (ACS) estimates that 192,370 U.S. women will be diagnosed with invasive breast cancer in 2009. Of those, 40,610 will die. On the positive side, these numbers represent an overall decrease since the 1990s, which researchers attribute to a decrease in the number of women on hormone replacement therapy.

Although it doesn't look like we can prevent breast cancer altogether, you can shift the odds in your favor by making lifestyle changes--changes that should sound familiar to all of us: Eat a healthful diet that includes plenty of plant foods, stay active, maintain a healthy weight and drink alcohol only moderately or not at all.

In a recent American Institute for Cancer Research (AICR)/World Cancer Research Fund research review--the largest to look at lifestyle and breast cancer ever conducted--it was found that women can reduce their risk by 40 percent through such lifestyle changes.


If only it were as simple as chowing down on a bushel of blueberries or a side of salmon, we'd all be safe. Unfortunately, the "superfoods" connection isn't that clear-cut. Scientists are investigating so-called superfoods like berries, flax, soy, salmon and tea, to see if they offer significant protection. They are studying both the whole food, as well as individual nutrients, such as omega-3 fatty acids from salmon and walnuts, lignans from flaxseed, and antioxidants from tea to determine if they are protective.

So far, the research connecting these foods with cancer prevention has been inconsistent, but since these are foods that health experts recommend, it can't hurt to add them to your diet.

If you're wondering why so many research studies on health seem to contradict each other, the reason might well be genes. Each woman's unique genetic make-up may influence how her body uses certain foods. Susan McCann, Ph.D., R.D., Associate Member of the Division of Cancer Prevention and Population Sciences at Roswell Park Cancer Institute, Buffalo, NY, has an opinion about that: "Everyone's genes are different. So some people may benefit from a particular diet while others do not. Some people may need a different combination of fruits and vegetables and grains to gain the optimum advantage."


Does how we flavor our food affect cancer risk? Winston J. Craig, Ph.D., R.D., reports in an article in the American Society for Clinical Nutrition that the National Cancer Institute has identified several commonly used herbs as possessing cancer-preventive properties that make them worthy of adding to your menu. These include garlic, onions, chives, basil, mint, oregano, rosemary, sage, thyme, turmeric, ginger, licorice root, anise, caraway, celery, chervil, cilantro, coriander, cumin, dill, fennel, parsley and tarragon.


As early as the 1990s, cancer researchers were investigating the role that vitamin D might play in reducing breast cancer risk. Food sources of vitamin D are limited, but unlike with other vitamins, we can make our own supply of vitamin D with unobstructed exposure to ultraviolet rays from the sun.

A study in the International Journal of Epidemiology in 1990 supported a relationship between a reduction in breast cancer risk and regions with greater sunlight exposure. In a 2009 review article in Reproductive Sciences, researchers concluded that sufficient vitamin D may have a protective function on mammary cells, reducing breast cancer risk.

On the other hand, overexposure to ultraviolet rays is related to skin cancer. Using sunscreen to protect against skin cancer reduces the body's ability to absorb the sun's rays to make vitamin D. The solution? Some experts suggest getting 15 minutes of unprotected exposure a day and eating vitamin D-rich foods, such as salmon, egg yolks and vitamin-D fortified foods. You can consult your healthcare provider regarding assessing your vitamin D levels or whether supplementation is appropriate for you.


What if it's not one food, but a combination of foods or nutrients that reduce risk? French researchers found that breast cancer risk was reduced in women who consumed garlic and foods with fiber and onions in a 1998 study published in European Journal of Epidemiology. It may be a synergism among nutrients in many whole plant-based foods that offers protection.

Say "Cheers" to breast cancer risk reduction? One lifestyle factor stands out: Alcohol intake is linked with a higher risk of breast cancer. Women who have two to five drinks daily have about one-and-a-half times the risk of women who drink no alcohol. The ACS suggests that if you drink at all, limit it to one drink a day.


The Shanghai Breast Cancer Study, a large population-based cohort study involving 75,000 Chinese women that started in 1996, found that women with breast cancer were less physically active than women who did not have breast cancer.

According to an earlier study of post-menopausal women, breast cancer risk was substantially reduced for women who exercised at high levels throughout their lifetime. And a 2008 study conducted by the German Cancer Research Center found that physical activity during post-menopausal years might reduce risk for developing breast cancer by about one-third, independent of weight gain.


It also seems wise to maintain a healthy weight throughout life. According to the ACS, being overweight or obese is linked to a higher risk of breast cancer, especially for post-menopausal women and weight gain that takes place during adulthood. The risk seems to be higher if the extra fat accumulates in the waist area.

Perhaps the best advice for breast cancer prevention comes from Alice Bender, M.S., R.D., Nutrition Communications Manager for AICR, who says "Maintaining a healthy weight, avoiding alcohol and getting regular exercise are the lifestyle behaviors that current research indicates will make the most difference in reducing risk for breast cancer. A plant-based diet, with appropriate fats, is key to achieving and maintaining a healthy weight--so vegetables, fruits, legumes and whole grains play a role indirectly."


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Women's Health - Breast Cancer: Gain a Fighting Edge Through Diet and Lifestyle