Phytoestrogens as neuroprotectants.

Recent large clinical trials demonstrating deleterious effects of postmenopausal hormone replacement therapy have raised interest in the use of food products and extracts containing phytoestrogens as potential safe alternatives for menopausal symptoms, age-related cognitive decline and neurodegenerative diseases. While numerous preclinical studies and various clinical trials point to beneficial effects of estrogens on the brain, phytoestrogens from several sources share many of these estrogenic effects, in addition to having unique activities distinct from natural estrogens. Numerous in vitro and in vivo studies show potential neuroprotective properties of phytoestrogens on the brain in conditions ranging from aging to neurodegenerative disease and cerebral ischemia. Although dosage, timing and safety concerns remain to be addressed before their therapeutic use in human populations can be recommended, their safety profile and some intriguing studies on human cognition in aging suggest that further clinical study of these compounds for brain health is warranted. Copyright 2009 Prous Science, S.A.U. or its licensors. All rights reserved.