In order to clarify the mechanisms of the effects of isoffavones, many studies e been performed. Intestinal microbial cells can convert daidzein ifferent products, including the isoflavonoids equol, dihydrodaidzein, and O-des- nethylangolensin.% It has been proposed that genistein was metabolized t dihy dogenistein and 6 -hydroxy-o-desmethylangolensin in humans. 6 Estrogenic activ ties of isoflavones are quite weak when compared to those of physiologic trogens 97 However, consumption of soybean foods in blood isoflavone creased of physiologic concentrations to several orders of magnitude higher than those estrogens 98 Isoflavones can also have antiestrogenic effects when placed in a high estrogen environment .10 Genistein inhibits several enzyme activities involve in ignal transduction and DNA topoisomerases I and II. lo n addition, genistein increases the in vitro concentrations of transforming growth factor B (TGF-B), an inhibitor of epithelial cell growth. OS This effect is thought to be an important contributor to the anticancer effect. Isoflavones have been shown to bind the estrogen new receptor, been discovered, to which receptors (ERs). Recently, a ERA, has natural estrogen, 17B-estra- genistein can bind, but the binding is weaker than for diol 10% It is possible that this finding, and the fact that ERB is expressed in differing amounts depending on the types of cells, support the observation that isoflavones have antiosteoporotic but weakly antiuterotrophic effects.