Phytoestrogens are compounds found in plants that mimic the effects of estrogen in the body. Some supplement manufacturers seek to capitalize on the existence of plant-based estrogens by marketing them as an alternative to hormone replacement therapy, but according to the Center for Science in the Public Interest, there is a dearth of evidence regarding the effectiveness of such use.
Types of Phytoestrogen
According to the Centers for Disease Control and Prevention, there are two main groups of phytoestrogens, called isoflavones and lignans. Another type of phytoestrogen that has gained a lot of attention is resveratrol. These three different types of phytoestrogens are derived from a variety of foods.
Isoflavones
Isoflavones come in many different forms, such as formononetin, daidzein, biochanin A and genistein. Soybeans and soy products are by far the richest source of isoflavones. Soy is often used as protein to fortify processed foods, such as meats, meat substitutes and bread. The techniques used to create these products can alter the phytoestrogen content of isoflavones, so it is difficult to determine precisely how much phytoestrogen is contained within them. A study published in "Food Additives and Contaminants" in 2004 concluded that hidden sources of phytoestrogens, such as beer, were so prevalent in the UK that it's fair to assume that the dietary intake of these plant-based estrogens is higher than previously estimated. Kudzu root and citrus fruits also contain isoflavones.
Lignan
Like isoflavones, lignan phytoestrogens also come in a variety of forms, such as matairesinol and secoisolariciresinol. When you consume these forms of lignan, the beneficial bacteria that inhabit your small intestine break them down into enterolactone and enterodiol, substances known to have estrogenic effects. Whole-wheat flour, flax seeds and tea are all sources of lignan.
Resveratrol
Resveratrol is another phytoestrogen, and its popularity as a nutritional supplement has mainly centered on its potential as an aid in thwarting age-related diseases. According to "Thrombosis Research," red wine is rich in resveratrol. In January 2011, the journal published research that found that resveratrol affects blood clotting in ways that are similar to estrogen. Resveratrol is also found in grape skins and peanuts.
References
- Centers for Disease Control and Prevention: Chemical Information -- Phytoestrogens
- Center for Science in the Public Interest; Phytoestrogens for Menopause; David Schardt; January 2000
- "Food Additives and Contaminants"; Determination of unusual soya and non-soya phytoestrogen sources in beer, fish products and other foods; D.B. Clarke, et al; October 2004
- "Thrombosis Research"; Resveratrol, A Phytoestrogen Found in Red Wine, Down-Regulates Protein S Expression in HepG2 Cells; Y. Hiroto, et al; January 2011
Member Comments