Soy compound linked to lower breast cancer risk

Researchers found that among more than 24,000 middle-aged and older Japanese women, those with the highest levels of genistein, were only one-third as likely as other women to develop breast cancer over 10 years. Genistein is one of the major isoflavones, plant compounds found in soybeans, chick peas and other legumes that are structurally similar to the hormone estrogen, and are believed to bind to estrogen receptors on body cells. While some studies have linked soy consumption with a lower risk of breast cancer, others have found no protective effect. Some animal research, in fact, has suggested that genistein might spur tumor development and growth. The new findings, reported in the Journal of Clinical Oncology, suggest that this is not the case in women, at least when genistein is consumed through food alone. "This finding suggests a risk-reducing rather than a risk-enhancing effect of isoflavones on breast cancer, even at relatively high concentrations within the range achievable from dietary intake alone," write the researchers, led by Dr. Motoki Iwasaki of the National Cancer Center in Tokyo. The study included 24,226 women ages 40 to 69 who gave blood samples and completed a dietary assessment, then were followed for an average of 10 years. During that time, 144 women were diagnosed with breast cancer. When Iwasaki's team separated the women based on their blood levels of genistein at the study's start, they found that the one-quarter with highest levels were 65 percent less likely to develop breast cancer than the quarter of women with the lowest genistein levels.

Bonnie - this is consistent from what we have seen. Keep in mind several factors. Japanese women almost exclusively eat fermented soy (tofu, tempeh, miso, natto, etc.). Most of the soy consumed in the U.S. is NOT fermented. So please don't go running out to buy tons of soymilk, soynuts, soybeans, etc.