Researchers have started studying phytoestrogens (naturally occurring plant compounds that are similar to estrogen) and their potential role in preventing and treating osteoporosis and menopausal symptoms. The evidence has been conflicting. While it is safe to add these plant compounds to your diet in moderate amounts, synthetic isoflavones are not recommended.
Many postmenopausal women are looking for alternatives to hormone therapy, especially in light of research findings in 2003 from the Women's Health Initiative.
Phytoestrogens are naturally occurring plant compounds that are similar in some ways to estradiol, the most potent naturally occurring estrogen. However, phytoestrogens tend to have weaker effects than most estrogens, are not stored in the body, and can be easily broken down and eliminated.
Observational studies have found a lower prevalence of breast cancer, heart disease, and hip fracture rates among people living in places like Southeast Asia, where diets are typically high in phytoestrogens. As a result of these studies, a great deal of interest has been generated in the United States about the health benefits of phytoestrogens. According to the Food and Drug Administration (FDA), the sale of soy foods, a major source of phytoestrogens, has increased dramatically in the past decade.
Phytoestrogens consist of more than 20 compounds and can be found in more than 300 plants, such as herbs, grains, and fruits. The three main classes of dietary phytoestrogens are:
- Isoflavones (genistein, daidzein, glycitein, and equol) are primarily found in soybeans and soy products, chickpeas, and other legumes.
- Lignans (enterolactone and enterodiol) are found in oilseeds (primarily flaxseed), cereal bran, legumes, and alcohol (beer and bourbon).
- Coumestans (coumestrol) can be found in alfalfa and clover.
Most food sources containing these compounds typically include more than one class of phytoestrogens.