Eating soy foods during childhood may reduce breast cancer riskPrevious epidemiologic studies have already linked the consumption of soy foods with a reduced risk of breast cancer. Wu and co-workers at the University of Southern California were the first to conduct an epidemiologic case-control study specifically designed to investigate this association. They found that women consuming soy foods on a regular basis during adolescence and adulthood had half the risk of developing breast cancers than those who only eat little soy foods. They came to this conclusion after conducting a case control study in Asian women living in the US.
The study concluded that high soy food intake by Asians living in the US during adolescence was associated with a significant reduced risk of breast cancer and that this risk may be further reduced by high intake as an adult.
Source: Adolescent and adult soy intake and risk of breast cancer in Asian-Americans. Carcinogenesis. 2002 Sep;23(9):1491-6.