Phytoestrogens for menopausal vasomotor symptoms: efficacy of soybean isoflavones supplements for alleviating menopausal symptoms is positively related to hot flushes frequency

Abstract

Purpose of investigation: This study was designed to measure the beneficial effects of a combination of nutraceutics containing soy isoflavones (80 mg) and to evaluate the effect of soy isoflavones on hot flushes (HF) and quality of life in a clinical setting, as the authors conducted an observational study. Materials and Methods: This study was conducted on 92 patients with complaints of hot flashes, divided into two groups of 46 each. Group 1 received no therapy and group 2 received 80 mg of isoflavones daily for six months. The patients were interviewed to calculate hot flashes, global and depression scores and were rescored after 2, 4, 8, 12 and 24 weeks. The primary outcome measure was a change in the HF score from baseline. Results: A total of 92 patients, 46 (50%) in the treated group and 46 (50%) in the untreated group, entered the study. Extracts containing high levels of genistein (a substance derived from soy) appeared to reduce the number of daily HF and need to be investigated further. No indication suggested that discrepant results were due to the amount of isoflavones in the active treatment arm, the severity of vasomotor symptoms or trial quality factors. Also, no evidence indicated that these treatments caused oestrogenic stimulation of the endometrium or of the vagina or other adverse effects when used for up to one year. Conclusions: This observational trial suggests a possible beneficial effect of a dietary soy supplement containing 80 mg of isoflavones/day in the management of menopausal symptoms such as HF.