Genistein, a naturally occurring chemical present in soy, has attracted scientific interest for its possible benefits in cancer and heart disease prevention. Genistein is a type of chemical called a phytoestrogen—an estrogen-like substance present in some plants. There are two main types of phytoestrogens: isoflavones and lignans . Soy is the most abundant source of isoflavones, with genistein the most abundant isoflavone in soy. Red clover is also a good source of genistein.
Like other phytoestrogens, genistein can work in two ways: either by increasing or decreasing the effects of estrogen. This happens because genistein binds to special sites on cells called estrogen receptors. Genistein stimulates these receptors, but not as strongly as real estrogen; at the same time, it blocks estrogen itself from attaching. The net result is that when there is a lot of estrogen in the body, such as before menopause, genistein may partly block its effects. Since estrogen appears to increase the risk of various forms of cancer, regular use of genistein by premenopausal women might help reduce this risk. On the other hand, if there is little human estrogen present, such as after menopause, genistein can partly make up for it. This is one rationale for using genistein to treat menopausal symptoms and to prevent osteoporosis.
Genistein might also be helpful for reducing heart disease risk.
For more information on the proper dosage of isoflavones in general, see the full Isoflavone article.
Isoflavone mixtures containing genistein have undergone considerably more study than genistein alone. Mixed isoflavones have shown promise for most of the conditions just mentioned, as well as menopausal symptoms and cyclic mastalgia .
What Is the Scientific Evidence for Genistein?
Menopausal Symptoms (Hot Flashes)
Most safety studies that have implications for genistein involved mixed isoflavones from soy or red clover. For more information, see the Safety Issues section of the Isoflavone article.
- Reviewer: EBSCO CAM Review Board
- Review Date: 09/2014 -
- Update Date: 09/18/2014 -