How good are soy milk and soy products for you anyway? Well at least it does not adversely affect on women with breast cancer or that have survived this top killer. Data from a multi-institution collaborative study, the After Breast Cancer Pooling Project was used to draw these conclusions presented this week at the AACR 102nd Annual Meeting.

Xiao Ou Shu, professor of medicine at Vanderbilt Epidemiology Center, Vanderbilt University Medical Center said:

“There has been widespread concern about the safety of soy food for women with breast cancer. Soy foods contain large amounts of isoflavones that are known to bind to estrogen receptors and have both estrogen-like and anti-estrogenic effects. There are concerns that isoflavones may increase the risk of cancer recurrence among breast cancer patients because they have low estrogen levels due to cancer treatment.”

The chemical structure of isoflavones is very similar to that of estrogen. Because of this similarity in structure, they can interfere with the action of women’s estrogen. Depending on the type of estrogen receptor on the cells, isoflavones may reduce or activate the activity of estrogen.

Isoflavones can compete with estrogen for the same receptor sites thereby decreasing the health risks of excess estrogen. They can also increase the estrogen activity. If during menopause the body’s natural level of estrogen drops, isoflavones can compensate this by binding to the same receptor, thereby easing menopause symptoms as a result.

The best way to consume isoflavones is in the form of soy or soy foods, so you can benefit from other healthy components of soy. Soy contains many types of isoflavones, but the most beneficial are genistein and daidzein. The highest amounts of soy isoflavones can be found in soy nuts and tempeh. Another natural source of isoflavones is red clover.

The new study included 18,312 women between the ages of 20 and 83 years who had invasive primary breast cancer.

Soy isoflavones intake was assessed for 16,048 of these women on average of 13 months after breast cancer diagnosis using food frequency questionnaires for a group of soy isoflavones in three cohorts and on tofu and soy milk consumption in one cohort.

Women in the highest intake category of more than 23 mg per day of isoflavones had a 9% reduced risk of mortality and a 15% reduced risk for recurrence, compared to those who had the lowest intake level.

Shu adds:

“Our results indicate it may be beneficial for women to include soy food as part of a healthy diet, even if they have had breast cancer.”

The FDA recommends that consumers incorporate four servings of at least 6.25 grams of soy protein into their daily diet – a total of at least 25 grams of soy protein each day.

The FDA has authorized use of health claims about the role of soy protein in reducing the risk of coronary heart disease (CHD) on labeling of foods containing soy protein. This final rule is based on the FDA’s conclusion that foods containing soy protein included in a diet low in saturated fat and cholesterol may reduce the risk of CHD by lowering blood cholesterol levels.

Recent clinical trials have shown that consumption of soy protein compared to other proteins such as those from milk or meat, can lower total and LDL-cholesterol levels.

Source: Isoflavones Information

Written by Sy Kraft, B.A.