Potential Health Benefits of Dietary Phytoestrogens: A Review of the Clinical, Epidemiological, and Mechanistic Evidence1

Phytoestrogens represent a family of plant compounds that have been shown to have both estrogenic and antiestrogenic properties. A variety of these plant compounds and their mammalian metabolic products have been identified in various human body fluids and fall under two main categories: isoflavones and lignans. A wide range of commonly consumed foods contain appreciable amounts of these different phytoestrogens. For example, soy and flax products are particularly good sources of isoflavones and lignans, respectively. Accumulating evidence from molecular and cellular biology experiments, animal studies, and, to a limited extent, human clinical trials suggests that phytoestrogens may potentially confer health benefits related to cardiovascular diseases, cancer, osteoporosis, and menopausal symptoms. These potential health benefits are consistent with the epidemiological evidence that rates of heart disease, various cancers, osteoporotic fractures, and menopausal symptoms are more favorable among population...