Naturally occurring estrogenic chemicals in plants, also called phytoestrogens, have similar chemical structures to estrogenic compounds produced by the human body. The ability of phytoestrogens to bind to estrogen receptors throughout the human body is weaker than human-produced estrogens. In the 2011 issue of the "Australian Journal of Medical Herbalism," M Diana van Die, M.D., says eating phytoestogens may lower the risk for cardiovascular disease, osteoporosis and memory loss after menopause.
Phytoestrogen Food Sources
The type and concentration of estrogenic compounds in food varies. According to DietaryFiberFood.com, the four major groups of naturally occurring estrogenic chemicals in plants include isoflavones, flavones, coumestans and lignans. Isoflavones have antioxidant activity and can act at estrogen receptors. Lignans are converted to estrogenic compounds by enzyme action in the intestines. Coumestans have strong estrogenic activity with a chemical structure that allows it to bind strongly to estrogen receptors. According to the "Australian Journal of Medical Herbalism," soybeans contain the highest concentrations of isoflavones, flaxseeds and whole grains contain the highest concentration of lignans and red clover sprouts and alfalfa sprouts contain the highest concentration of coumestans.
Isoflavones and Memory
Soybeans are high in isoflavones used in estrogen replacement therapy. Estrogen influences areas of the brain for cognition and behavior. According to the July 2003 issue of "Journal of the American Dietetic Association" research indicates that both women and men on a high soy diet show improved episodic memory and function in the frontal lobe function of the brain.
Dietary Lignan Benefits
A study of pregnant women published in the October 2010 issue of "Reproductive Health" shows that participants who received dietary counseling to increase lignan-containing foods showed increases in lignans circulating in the blood. The researchers point out that lignans found in plants that are high in fiber including seeds, whole grains, vegetables, fruits and berries may provide protection from cardiovascular disease and breast and colon cancer.
Phytoestogens and Menopause
Phytoestrogens can be used in hormone replacement. A review of research published in the 2011 issue of "Australian Journal of Medical Herbalism" indicates estrogenic chemicals in soy, in particular the isoflavone genistein, may provide some benefit for reducing hot flashes. Die also says phytoestrogens reduce cholesterol and may help protect bone density after menopause.
Cautions
The Fall 1998 issue of "Forum for Applied Research and Public Policy," suggests that exposure to estrogenic compounds may play a role in lowered sperm counts and testicular cancer. Research is needed to determine long-term safety and mechanism of action of estrogenic compounds from the diet. Safety considerations related to breast and endometrial cancer published in the 2011 issue of "Australian Journal of Medical Herbalism" indicate that isoflavones bind to estrogen receptors and may increase risk for estrogen dependent tumors.
References
- "Australian Journal of Medical Herbalism"; Phytoestogens in Menopause; M Diana van Die Ph.D.; 2011
- DietaryFiberFood.com: Phytoestrogen and Its Food Sources
- "Journal of the American Dietetic Association"; New Studies: Soy Appears to Benefit Cognitive Function; Sandra E. File; July 2003
- Reproductive Health; Effect of Dietary Intervention on Serum Lignan Levels in Pregnant Women; Riitta Luoto et al.; October 2010
- "Forum for Applied Research and Public Policy"; Disruptive behavior. Relationship Between Environmental Pollutants, Male Fertility and Breast Cancer; Stephen H. Safe and Kavita Ramamoorthy; Fall 1998
