A study at the University of Texas Medical Branch at Galveston, to be presented during the 90 th annual meeting of the American Association for Cancer Research, shows that soya consumption may reduce breast cancer risk by lowering a woman's female hormone levels. Population-based studies have shown that soybean consumption is associated with reduced risk for breast, prostate and colon cancers.
Soybeans contain a significant quantity of estrogen-like compounds called isoflavones.
These isoflavones have been shown in animal models and in tissue cultures to be weak estrogens. Research has shown that they inhibit cell growth and blood vessel formation and induce cells to differentiate. High levels of ovarian steroids have been postulated to be risk factors for developing breast cancer. People from areas with low risk for breast cancer, such as Asia, produce lower levels of ovarian hormones than people residing in areas, such as America, with a high risk for breast cancer. Breast cancer patients produce higher endogenous levels of estrogens than non-breast cancer subjects.