While research findings suggest there might be a slight benefit for women including soy in the diet as a
measure of breast cancer prevention, there is doubt that soy has any substantial benefit, and might actually cause more harm than good."At this point, women should not be taking high-dose soy supplements, especially those who are breast cancer survivors and women at increased risk for the disease," said Bruce Trock at Johns Hopkins' Brady Urological Institute and Kimmel Cancer Center. "We don't have long-term data on the effects of these supplements, and there is some evidence that they could be harmful."
Trock has research to back up his statement. In animal testing, soy products showed an increase in tumor growth. In human studies, they were able to observe changes in breast cell growth that might actually increase risk for breast cancer.
In the 1980's, soy became popular as a cancer prevention food after early laboratory data showed that high doses of compounds within soy, called isoflavones, may block estrogens, promote cell death and have anti-inflammatory qualities. Asian women, who have much lower rates of breast cancer, include tofu and bean curd, both soy foods, in their daily diet, and this was held up as an example of the benefits of soy. But, as Trock points out, "We need to take into account that Asian women are more physically active, drink less alcohol, have children earlier, and their entire diet is different from Western women, all of which decrease their breast cancer risk." The jury is still out on the subject of soy, and from the estrogen-positive breast cancer survivors I know, most are steering clear of soy at this time because there are too many questions still unanswered.











1. Portions of the original study were left out of this article. The original research with soy was done with SOY SUPPLEMENTS, and not with SOY FOODS. The use of the term "products" suggests soy foods were used. Below is a critical paragraph left out of this article.
"After averaging results from the studies, which span a quarter century, the overall relative reduction in breast cancer risk for soy eaters was a modest 14 percent in Caucasian women. The effect was not statistically significant in Asian women. Differences in pre- and postmenopausal women were slight and potentially biased due to the small number of studies that accounted for menopausal status."
Posted at 1:42PM on Apr 10th 2006 by Barbara Havlena