Pharmacokinetics of Dietary Isoflavones

Dietary isoflavones are reported to have significant influences on human health. The beneficial effects reported include reduced risk of cancers, decreased menopausal symptoms, reduced osteoporosis etc. Most of these benefits have been deduced from epidemiological studies involving soy bean as the source of dietary isoflavones, since soy bean is an important food crop in several parts of the world. Over the last 30 years, considerable progress has been made in understanding the fate of dietary isoflavones in humans. Now we understand that the pharmacokinetics of dietary isoflavones is a complex phenomenon and involving multifaceted biological processes. The role of gut micro flora in deciding the bioavailability of isoflavones is quite significant. This review examines various pharmacokinetic aspects of dietary isoflavones and factors influencing the systemic bioavailability of isoflavones. This review also attempts to identify important factors which may contribute to the inter-person differences in the effects of isoflavones. A. Isoflavone ring system showing the ring nomenclature and numbering