ABSTRACT
Phytoestrogens are naturally occurring chemicals of plant origin that have the ability to cause estrogenic and/or antiestrogenic effects due to their structural similarities to the human hormone estradiol. The majority of phytoestrogens belong to a large group of substituted phenolic compounds known as flavonoids. Evidence is beginning to accrue that phytoestrogens may begin to offer protection against a wide range of human conditions, including breast, bowel, prostate, and other cancers; cardiovascular disease; brain function; alcohol abuse; osteoporosis; and menopausal symptoms. In general, phytoestrogens are relatively weak oestrogens, requiring much higher concentrations than estradiol to produce an equivalent biological response. Isoflavones are polyphenolic phytoestrogens that occur mainly as gluco-conjugates of genistein, daidzein, and glycitein. All the phytoestrogens and their metabolites contain at least one aromatic ring. Applications of phytoestrogens in industry are becoming prevalent. There is a global movement toward increased consumption of foods rich in phytoestrogens and tablet formulations of concentrated isoflavone extracts.
