Soy foods are rich in phytoestrogens and have controversial health benefits. Research on soy related to coronary heart disease (CHD), osteoporosis, cancer, cognition, and symptoms of menopause yield weak, inconsistent results. However, the U.S. Food and Drug Administration (FDA) allowed [Page 1290]health claims for soy foods in 1999, and soy markets quickly expanded. Increased intake of soy and contradictory research on health benefits remain a concern. This entry describes soy and phytoestrogens in food, health, policy, and controversies.