Hormone replacement therapy is used to diminish the symptoms of menopause, which can include hot flashes, mood swings and vaginal dryness. Many plant based foods contain phytoestrogens, and supplement manufacturers have created products based on the hypothesis that the estrogen found in these foods many help alleviate menopausal symptoms. This theory remains unproven, however, and you should not take phytoestrogen supplements without a doctor's recommendation. According to Cornell University, more research needs to be conducted to determine possible links between phytoestrogens and breast cancer.
What are Phytoestrogens?
Phytoestrogens are substances found in plants that have molecular structure similar to that of estrogen and bind to estrogen receptors in the body. Isoflavones, resveratrol and coumestans are three phytoestrogens found in food. Soybeans are rich in isoflavones. Grapes provide resveratrol. Alfalfa and clover sprouts have the highest concentration of coumestans, according to the Program on Breast Cancer and Environmental Risk Factors at Cornell University.
Soybeans
Soybeans are the largest source of phytoestrogens, according to the Centers for Disease Control and Prevention. Daidzein and genistein are two isoflavones found in soybeans and soybean products such as tofu. A study comparing the effects of soy isoflavones to hormone replacement therapy found that soy caused fewer or no adverse side effects compared to hormone replacement therapy, but soy was far less effective than HRT in relieving menopausal symptoms or osteoporosis.
Grapes
Grapes and grape products such as red wine contain resveratrol, a phytoestrogen that mimics some effects of estrogen while blocking others. Resveratrol is a popular supplement due to reports that it may be behind the "French paradox," the observation that French diets, typically high in saturated fat and cholesterol, have not resulted in high rates of heart disease among the French. According to NYU's Langone Medical Center, resveratrol is thought to have effects similar to soy, but there have not been sufficient studies to confirm these effects.
Sprouts
Clover and alfalfa sprouts are the richest source of coumestan phytoestrogens. This class of phytoestrogen has received the least amount of scientific study, according to Cornell. Coumestans are known to form powerful bonds with estrogen receptors in the body and are thus believed to have estrogenic effects. The dearth of research into this area means that more studies are needed to confirm the estrogenic effects of the coumestan found in sprouts.
References
- Center for Science in the Public Interest: Salt: Phytoestrogens for Menopause; David Schardt; January/February 2000
- "The Journal of Nutrition"; Soybean Isoflavones as an Alternative to Traditional Hormone Replacement Therapy: Are We There Yet?; Gregory L. Burcke, et al.; March 2000
- Centers for Disease Control and Prevention; Chemical Information: Phytoestrogens; April 2001
- Cornell University; Phytoestrogens and Breast Cancer; Barbour S. Warren, et al.; July 2002
- NYU Langone Medical Center: Resveratrol; February 2011
- "The American Journal of Clinical Nutrition"; Phytoestrogens and Breast Cancer; Regina G. Ziegler; February 2004
