Soy Protein & Estrogen

Soy protein contains phytoestrogens, which are nonsteroidal estrogens of plant origin. These estrogen-like compounds are called isoflavones. Soy isoflavones have estrogenic activity that is approximately 1000-fold weaker compared to steroidal estrogen. Therefore, soy phytoestrogens are believed to have both anti-estrogenic and estrogenic effects. Currently, researchers are gaining insight into the health effects of soy. If you want to use soy protein, talk to your doctor first.

Soy Estrogens and Menopausal Symptoms

In recent times, soy has attracted much scientific attention as a dietary supplement for menopausal symptoms. However, more research is needed to determine its safety and effectiveness. Menopausal symptoms, such as anxiety, depression, insomnia, hot flashes and night sweats, are mostly associated with low levels of estrogen and high stress levels. Soy isoflavones can occupy estrogen receptors and act as estrogens in humans. Thus, soy isoflavones can help mitigate menopausal symptoms.

Soy Estrogens and Osteoporosis

Soy isoflavones can help women with progressive bone loss disease, which is also called osteoporosis. Older women are more vulnerable to osteoporosis and fractures. In fact, soy isoflavones can curb reduced bone density in menopausal women. Estrogen deficiency may be a cause of osteoporosis in aging women. Soy isoflavones resemble the body's own estrogen and thus can prevent excessive bone loss after menopause.

Soy Estrogens and Breast Cancer

Animal studies used to examine the effect of human and plant estrogens in breast cancer have given contradictory results. Genistein is the most robust isoflavone found in soy. It has been found that genistein administered to pre-pubertal female rats reduced the incidence of chemically induced mammary cancers. Other studies showed that genistein influenced the growth of existing estrogen-responsive breast cancer tumors.

Safety

More research is needed to prove the safety of soy isoflavones. Clinicians recommend isoflavones from whole foods, such as soy milk, soy sprout, soy flour and miso. Clinical trials showed that a daily diet containing 25g of soy protein provides about 50mg of isoflavones per day.