Update on isoflavones during menopause: First-line treatment for mild climacteric disorders

Abstract

Isoflavones are so-called phyto-SERMs (Selective estrogen receptor modulators) and may be considered as a first-line treatment in mild climacteric disorders. They bind almost exclusively to estrogen receptor beta (ER-β) and exert corresponding therapeutic downstream effects within the cells. Extensive preclinical and clinical studies have demonstrated these effects as well as effects on other metabolic pathways such as the peroxisome proliferator-activated receptor (PPAR) system. Randomized controlled clinical trials and meta-analyses clearly showed a reduction of typical menopausal hot flushes and other menopausal complaints. Results are, however, quite heterogeneous with respect to different phytoestrogens used, different dosages, interindividual, ethnic, and geographical aspects. The influence of phytoestrogens on surrogate parameters concerning cardiovascular risk such as lipid and glucose metabolism or the metabolic syndrome or even osteoporosis seem to be favorable; however, studies with hard endpoint data such as heart attack, stroke, or fracture rates are scarce. The European Food Safety Authority stated in 2015 that after thoroughly investigating isoflavones, any increase in the risk of breast cancer, endometrium stimulation or thyroid function could not be demonstrated with dosages between 35 and 150 mg/day.