"Phytoestrogens, being weak estrogens, are like small, private planes with few passengers and no cargo, yet they still occupy the Jetway after landing. When phytoestrogens occupy the cell, normal estrogens cannot. Plant estrogens do not eliminate all of estrogen's effects, but they do minimize them, apparently reducing breast cancer risk and menstrual symptoms.
For men and boys, the phytoestrogens in soy do not appear to have any effect on hormone levels and have not been shown to affect sexual development or fertility. Research studies show that men consuming soy have less prostate cancer and better prostate cancer survival."
> Phytoestrogens, natural plant compounds abundantly found in soy and soy products, behave as weak estrogen mimics or as antiestrogens. They are considered to be EDCs [endocrine disrupting compounds], and have some beneficial effects on health, including reducing the risk of breast cancer and improving metabolic parameters. However, the supporting evidence that consumption of phytoestrogens is beneficial is indirect and inconsistent. Lifetime exposure to estrogenic substances, especially during critical periods of development, has been associated with formation of malignancies and several anomalies of the reproductive systems.
https://news.ycombinator.com/item?id=14855796