Effects of the Phytoestrogen Genistein on Bone Metabolism in Osteopenic Postmenopausal Women

Background: Observational studies and small trials of short dura-tion suggest that the isoflavone phytoestrogen genistein reduces bone loss, but the evidence is not definitive. Objective: To assess the effects of genistein on bone metabolism in osteopenic postmenopausal women. Design: Randomized, double-blind, placebo-controlled trial. Setting: 3 university medical centers in Italy. Patients: 389 postmenopausal women with a bone mineral density (BMD) less than 0.795 g/cm2 at the femoral neck and no signifi-cant comorbid conditions. Intervention: After a 4-week stabilization period during which par-ticipants received a low-soy, reduced-fat diet, participants were randomly assigned to receive placebo (n 191) or 54 mg of genistein (n 198) daily for 24 months. Both the genistein and placebo tablets contained calcium and vitamin D