Diet is believed to play an important role in
cancer. It has been revealed by epidemiological studies that Asian populations, who consume
phytoestrogens in large amounts, have a lower incidence of
prostate cancer in comparison with the Western world, where consumption of soy is lower.
Genistein and
daidzein, the soy
phytoestrogens most widely studied, are believed to be potent
anticancer agents and have been shown to possess anticancer properties. It has been shown that these compounds inhibit the growth of
cancer cells through the modulation of genes controlling cell-cycle progression.
Genistein inhibits the activation of the kappa light
polypeptide gene enhancer in B-cells (NF-κB), signaling pathway, which is implicated in the balance between cell survival and programmed cell death (apoptosis).
Antioxidant and antiangiogenesis properties of
genistein have been also described. Soy
isoflavones are also implicated in reversion of epigenetic events observed in
prostate cancer. Significant advances have been made for understanding how soy
isoflavones are implicated in protection against
prostate cancer. However, more studies are needed to better-understand and elucidate all pathways mobilized by
genistein and
daidzein, in order to fully exploit their anticancer properties.