Psychological assessment of the effects of treatment with phytoestrogens on postmenopausal women: a randomized, double-blind, crossover, placebo-controlled study

Objective To investigate the effects of soy isoflavones on mood and cognitive function in postmenopausal women. Design Randomized, double-blind, cross-over, placebo-controlled trial. Setting University Hospital, Milan, Italy; A.G.UN.CO. Obstetrics and Gynaecology Centre, Rome, Italy. Patient(s) Seventy-eight postmenopausal women. Intervention(s) We administered 60 mg/day isoflavones or placebo for 6 months. After a washout period of 1 month, the patients who had been treated with phytoestrogens received placebo, and those who previously received placebo were administered phytoestrogens (for 6 months). Main Outcome Measure(s) Cognitive performance and mood were assessed by a battery of tests at the end of each treatment period. At the end of the study, the patients were also asked whether they preferred the first or second treatment. Result(s) The 17 scores on cognitive performance test and the 6 for mood assessments 6 showed an advantage for the treatment with phytoestrogens. Similarly, of the 8 visual analogue scales used to indicate mood, 7 improved significantly after the treatment with phytoestrogens. Moreover, 49 patients preferred phytoestrogens, 9 placebo, and 18 had no preference. The preference was not related to the order of treatment. Conclusion(s) These results suggest that isoflavones may have positive effects on postmenopausal women improving cognitive performance and mood.