Following a diet high in phytoestrogens during adolescence may protect a woman from breast cancer in adulthood.

This study evaluated how high dietary ingestion of phytoestrogen during adolescence affects a woman's chances of developing breast cancer in adulthood. The study population included 3,024 women diagnosed with breast cancer and 3,024 Canadian women without the disease. 

Researchers noticed that the odds of developing breast cancer in adulthood declined significantly among women who enjoyed consuming high-phytoestrogen foods as adolescents. This study concluded that "adolescent dietary phytoestrogen intake may be associated with a decreased risk of adult breast cancer."