Risks and benefits of phytoestrogens: where are we now?

The estrogenic effects of genistein, as reconfirmed by the American National Toxicology Program (USA-NTP), have led to several new clinical studies being undertaken. Here, we highlight the most relevant recent data, reporting either beneficial or adverse effects.

Phytoestrogens are natural molecules from edible plants exhibiting estrogenic activities. Post-USA-NTP studies investigated both human and animal reproductive and other physiological issues. These studies showed that estrogens can be either deleterious for reproduction and estrogen-dependent diseases, or beneficial for those with steroid deficiencies, that is more than 50. The specific outcome depends on exposure level and on the estrogenic status of the patients exposed. Recently, it was reported that, with the industrialization of soybean process, phytoestrogen exposure dramatically increased in both humans and cattle, whereas traditional Asian soy-food-processing empirically removed isoflavones. Phytoestrogen exposure has also become more widespread with the progressive internationalization of soybean use in human and cattle food.

Phytoestrogens should be considered as modern endocrine disruptors and studied as such.