Soy for the treatment of perimenopausal symptoms--a systematic review.

OBJECTIVES Many women have turned to complementary and alternative medicines for relief from their perimenopausal symptoms. The prevalence of plant-based medicine use among perimenopausal women highlights the need for investigation into these interventions. The aim of this study was to evaluate the benefit of soy preparations for the treatment of perimenopausal symptoms by performing a systematic review of randomised clinical trials (RCTs). METHODS Literature searches were performed using four computerised databases to identify RCTs of soy preparations for the treatment of perimenopausal symptoms. Manufacturers of soy products were contacted and our own files were also searched. There were no restrictions on the language of publication. Trials were considered if they used mono-preparations of soy or soy isoflavones, and if the outcome measures related to the physical and/or psychological impact of menopause in healthy women and scored at least three on the Jadad scale. RESULTS Thirteen RCTs were identified that investigated the use of soy preparations for perimenopausal symptoms. Ten of these trials fitted our inclusion criteria. The results of these studies are not conclusive. Four of these randomised controlled trials were positive, suggesting soy preparations are beneficial for perimenopausal symptoms. Six were negative; with one of the six showing a positive trend. CONCLUSIONS There is some evidence for the efficacy of soy preparations for perimenopausal symptoms. However, the heterogeneity of the studies performed to date means it is difficult to make a definitive statement. Adverse event data from the trials suggest that there are no serious safety concerns with soy products in short-term use.