Epidemiology of soy exposures and breast cancer risk.

High consumers of isoflavone-rich soy foods are less likely to develop breast cancer than rare- or non-consumers.

This study examined the effect of high dietary exposure to isoflavone-rich soy foods on breast cancer risk. Researchers reviewed data extracted from 11 published literatures on the subject. They observed that habitual consumption of more than 20 mg of isoflavone-rich soy foods per day significantly decreased the odds of developing breast cancer. On the other hand, daily dietary intake of 0.8-0.15 mg of isoflavones was found to have little or no effect on breast cancer risk. The findings of this review show that regular eating of large servings soy foods may protect women against breast cancer.