CHAPTER 29. Isoflavones and Prenatal Exposure to Equol

Polyphenolic compounds and more specifically isoflavonoids possess health benefits. Isoflavonoids are found naturally in plants, food products, beverages, and meat products, and are absorbed and/or metabolized in the gastrointestinal tract of mammals. The isoflavonoids molecules daidzein, genisten and equol (a metabolite of daidzein), particularly equol, are strong antioxidants. There is widespread historical exposure in various countries to isoflavonoid molecules, and the safety data in humans are without adverse health effects. Comparisons between human and rat newborn and adult parameters are presented. Equol is unique, being expressed in two different chemical confirmations, S-equol and R-equol, and both specifically bind 5α-dihydrotestosterone (5α-DHT). Perinatal studies demonstrate trans-placental transport of isoflavonoids in mammals. Animal studies covering perinatal development have examined genistein or equol in various doses and time intervals over a wide range of parameters. Studies in women during prenatal development or at birth provide valuable data for the quantification of isoflavonoid levels in the maternal, amniotic and fetal compartments. Animal studies provide valuable basic science information and serve as a data reference. However, animal data may corroborate or display divergent results compared with that observed in the human model. Therefore, further research is warranted to reveal the many benefits of isoflavonoid molecules in human health.