Estrogens have both benefits and risks.
Phytoestrogens are prototypical environmental estrogens known to induce infertility in livestock fed phytoestrogen-containing forage. Human exposure during development occurs primarily through phytoestrogen-rich soy infant formula. These data, taken together, suggest that it is important to define the degree of hazard, if any, caused by human, livestock or wildlife exposure to phytoestrogens so that potential risks and potential benefits, and the conditions under which they occur, can be defined.