Genistein is a molecule classified as an isoflavone that is structurally similar to 17β-estradiol. It is found in soybeans, legumes such as fava beans, and kudzu. Genistein has been shown to support the body’s response to chronic inflammation. It may also help support bone and cellular health, cardiovascular function, and postmenopausal health. In addition, recent research indicates that it may play a supportive role in the presence of polycystic ovary syndrome (PCOS).

PCOS is a common endocrine disorder associated with certain genetic variants related to inflammation and androgen biosynthesis. The incidence of PCOS may often be associated with an elevated luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratio. Complications associated with PCOS include acne, alopecia, and abnormal uterine bleeding. Quality of life among those with PCOS is also lower when compared to healthy individuals and those with other gynecological illnesses.

A recently published systematic review by Nasimi Doost Azgomi and colleagues explored the potential role of genistein in the presence of PCOS. Nine animal studies and four clinical trials were included. Some animal studies involving genistein and PCOS models reported significant decreases in interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and the number of cystic follicles. Other animal studies reported significant improvements in ovarian secretory function, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and FSH levels, and LH/FSH ratios during genistein administration. Parameters related to antioxidative status, including glutathione, glutathione peroxidase, and superoxide dismutase activity, were also shown to improve in these animal studies.

The four clinical studies included in this systematic review ranged in sample size from 24 to 146 participants. Amounts of genistein varied from 36 to 50 mg daily and study durations were between 3 days and 12 weeks. Significant decreases in HOMA-IR, total cholesterol, triglycerides, low-density lipoprotein, testosterone, and LH were reported. Other improvements reported were in dehydroepiandrosterone (DHEA), high-sensitivity C-reactive protein (hs-CRP), glutathione, and malondialdehyde levels. Genistein was also reported to help support the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) which the authors postulate may help support mitochondrial function and healthy ovarian secretion of estrogen and progesterone.

Drawbacks to the study include a lack of heterogeneity in the amount of genistein administered. One clinical study that was included in the systematic review involved the administration of soy milk and did not quantify specific genistein amounts. More research is needed before clinical conclusions can be made.

Isoflavones have been shown to play a role in many aspects of health including supporting metabolic function, cardiovascular health, and a healthy inflammatory response. In addition, genistein may support health in the presence of PCOS.

By Colleen Ambrose, ND, MAT