nutrients Review Isoflavone Supplements for Menopausal Women: A Systematic Review 1,2, 1, 3,4, Li-Ru Chen y, Nai-Yu Ko y and Kuo-Hu Chen * 1 Department of Physical Medicine and Rehabilitation, Mackay Memorial Hospital, Taipei 10449, Taiwan;
[email protected] (L.-R.C.);
[email protected] (N.-Y.K.) 2 Department of Mechanical Engineering, National Chiao-Tung University, Hsinchu 300, Taiwan 3 Department of Obstetrics and Gynecology, Taipei Tzu-Chi Hospital, The Buddhist Tzu-Chi Medical Foundation, Taipei 23142, Taiwan 4 School of Medicine, Tzu-Chi University, Hualien 970, Taiwan * Correspondence:
[email protected]; Tel.: +886-2-6628-9779 These authors contributed equally to this work. y Received: 17 September 2019; Accepted: 29 October 2019; Published: 4 November 2019 Abstract: Isoflavones have gained popularity as an alternative treatment for menopausal symptoms for people who cannot or are unwilling to take hormone replacement therapy. However, there is still no consensus on the effects of isoflavones despite over two decades of vigorous research. This systematic review aims to summarize the current literature on isoflavone supplements, focusing on the active ingredients daidzein, genistein, and S-equol, and provide a framework to guide future research. We performed a literature search in Ovid Medline using the search terms “isoflavone” and “menopause”, which yielded 95 abstracts and 68 full-text articles. We found that isoflavones reduce hot flashes even accounting for placebo effect, attenuate lumbar spine bone mineral density (BMD) loss, show beneficial effects on systolic blood pressure during early menopause, and improve glycemic control in vitro. There are currently no conclusive benefits of isoflavones on urogenital symptoms and cognition.