Soy contains certain isoflavones called genistein, daidzein and glycitein. They are called phytoestrogens because they are structurally similar to the hormone estrogen — and they interact with the estrogen receptors in the body. But instead of being dangerous, these isoflavones may be responsible for the beneficial effects of soy consumption! For example, women undergoing menopause can benefit from adding soy to their diet to deal with hot flashes.