RESUMO
1. This study examines whether the supplementation of isoflavones (ISO) exerts beneficial effects on the bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DEXA). 2. Eighty-one healthy Japanese pre- and postmenopausal women were randomly assigned to the following two groups taking either ISO (100 mg) tablets (ISO group) or placebo tablets (P group) containing vitamins C (25 mg) and E (5 mg) daily for 24 weeks in a double-blind placebo controlled parallel design. 3. Seventy women completed the intervention study (34 on ISO, 36 on P), only ISO group was proven to increase significantly BMD (P < 0.05 vs before) and to significantly decrease body fat measured by the DEXA (P < 0.0001 vs before and P < 0.05 vs P group), while BMI was maintained in ISO group despite significant BMI increase in P group. Thus, percent changes in BMI were significantly different between ISO and P groups (P < 0.05) 24 weeks after the intervention. 4. This prospective DEXA study confirmed a long-term ISO supplementation, 100 mg/day could not only prevent menopausal bone resorption but also increase BMD and decrease body fat concomitantly with BMI reduction. Enough ISO supplementation may contribute to the risk reduction of osteoporosis and obesity and, thus to overall health promotion in menopausal women.