Estrogen receptor-mediated effects of isoflavone supplementation were not observed in whole-genome gene expression profiles of peripheral blood mononuclear cells in postmenopausal, equol-producing women

Isoflavones (genistein, daidzein, and glycitein) are suggested to have benefits as well as risks for human health. Approximately one-third of the Western population is able to metabolize daidzein into the more potent metabolite equol. Having little endogenous estradiol, equol-producing postmenopausal women who use isoflavone supplements to relieve their menopausal symptoms could potentially be at high risk of adverse effects of isoflavone supplementation. The current trial aimed to study the effects of intake of an isoflavone supplement rich in daidzein compared with placebo on whole-genome gene expression profiles of peripheral blood mononuclear cells (PBMCs) in equol-producing, postmenopausal women. Thirty participants received an isoflavone supplement or a placebo for 8 wk each in a double-blind, randomized cross-over design. The isoflavone supplement was rich in daidzein (60%) and provided 94 mg isoflavones (aglycone equivalents) daily. Gene expression in PBMCs was significantly changed (P