The role of isoflavones in cancer chemoprevention.

Cancer is one of the major health problems around the world. However, it has been estimated that more than two-thirds of human cancers could be prevented by modification of lifestyle including dietary modification.The incidences of hormone-related cancers are much higher in Western countries compared to Asian countries. One of the major differences in diet between these populations is that the Asians consume a traditional diet high in isoflavones. Epidemiologic evidence together with data from animal and in vitro studies strongly supports relationship between isoflavones and the lower risk of cancers. Isoflavones have been shown to inhibit carcinogenesis in vivo in animal experiments. It has been known that genistein, one of the major isoflavones, inhibits the growth of various cancer cells through the modulation of genes that are related to the control of cell cycle, apoptosis, and cell signaling pathways. Moreover, genistein has been found to be a potent inhibitor of oxidative stress, angiogenesis, and metastasis.Therefore, isoflavones exert beneficial effects on human health and may be promising agents for cancer prevention and/or treatment. However, further in depth experimental investigations along with clinical trials are needed to fully evaluate the value of isoflavones in human cancer prevention and/or treatment.