Diet plays a huge role in the prevention of almost every disease. American women have five times the risk of developing breast cancer as Japanese women who consume a traditional Japanese diet. Second- and third-generation Japanese-American women who adopt a typical American diet have almost the same incidence of breast cancer as other American women. And a Westernized diet in Japan is now causing an increase in breast cancer among women there.

Here are some lifestyle measures for prevention:

* Get active. Regular physical activity, at least 30 minutes on most days, has been shown to be protective against breast cancer. This may be because it results in weight loss and decrease in body fat; therefore, it lowers circulating estrogen levels.

* Reduce exposure to xenoestrogens. We are exposed to a large number of synthetic chemical compounds that have estrogen-like activity. These include common pesticides, industrial pollutants and hormone residues in meat, poultry and dairy products. While the research on their link with breast cancer is conflicting, we recommend limiting exposure as much as you can. Choosing hormone-free dairy and animal products and organic produce is a good start.

* Early detection is key. Women ages 20-39 should have a clinical breast exam performed by a health care professional every three years in addition to conducting a self-examination every month. If you are 40 years of age or older, annual breast exams and mammograms are recommended. Your physician may request one at an earlier age if you display other risk factors.

Nutrition and Supplements

* Pay close attention to your diet. The original thought that breast cancer risk increased with a high-fat diet may have been too simple. There are several factors that we now believe are more closely associated with risk.

* Choose fats wisely. Studies have shown that women with a higher intake of olive oil have less breast cancer. Omega-3 fats, found in cold-water fish (especially wild salmon and sardines), freshly ground flaxseed and walnuts have also been associated with inhibiting the growth of breast tumors.

* Eat generous amounts of vegetables and fruit, which are loaded with cancer-protective phytochemicals. Our recommendation is 8 to 10 servings a day.

* Use freshly ground flaxseed or other sources of fiber every day. Diets that are high in fiber - lignins specifically – seem to increase the excretion of estrogen or modify the metabolism of estrogen and reduce the risk of breast cancer.

* Eat more soy. There has been some recent discussion on the possible negative effect of soy on risk of breast cancer, especially hormone receptor positive forms of the disease. Although the isoflavones in soy do have a mild estrogenic effect (they are able to bind to estrogen receptor sites in human tissue), soy foods also contain many cancer-protective substances. For this reason, and also because population studies have failed to show a relationship between soy consumption and increased risk of breast cancer, we recommend one serving of whole soy foods a day.

* Make green tea your beverage of choice. Green tea consumption is linked with lower incidence of many kinds of cancer.

* Drink very little, if any, alcohol. Alcohol consumption, even in modest amounts, is associated with increased risk of breast cancer.

* Take a multivitamin with folic acid, vitamin D and antioxidants. All these nutrients have been shown to be related to a reduced risk of breast cancer. Although the diet should be the primary source of most of these, a good daily supplement can help provide insurance that your intake is adequate.

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