The effects of quercetin supplementation on metabolic and hormonal parameters as well as plasma concentration and gene expression of resistin in overweight or obese women with polycystic ovary syndrome
What this study found
Quercetin showed favorable effects on several PCOS-related biomarkers, especially resistin and androgen-related measures. Plasma resistin fell from 2.88 ± 0.46 to 2.07 ± 0.23 ng/ml in the quercetin arm versus 2.85 ± 0.37 to 2.88 ± 0.40 ng/ml with placebo, with between-group significance after adjustment (adjusted p < 0.001); resistin mRNA expression was also lower with quercetin (0.64 ± 0.58 vs 1.00 ± 0.56 fold change, p = 0.008). Testosterone and LH also improved, with adjusted p values of 0.001 and 0.035, respectively. Fasting glucose, insulin, and HOMA-IR improved within the quercetin…
- Study & population
- This was a 12-week placebo-controlled intervention in overweight or obese women with polycystic ovary syndrome (PCOS) recruited from hospitals affiliated with Tehran University of Medical Sciences in Tehran, Iran.
- Intervention
- Quercetin was given orally at 1,000 mg/day for 12 weeks, using 500-mg capsules taken as two capsules daily with main meals, preferably breakfast and lunch.
- Key limitation
- The trial was relatively small and lasted only 12 weeks, which limits confidence in durability and broader applicability.
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Open PDFOriginal abstract
The aim of this study was to investigate the effect of quercetin on metabolic and hormonal parameters as well as plasma concentration and gene expression of resistin in overweight or obese women with polycystic ovary syndrome (PCOS). In this randomized, double‐blind, placebo‐controlled trial, 78 overweight or obese women (25 ≤ BMI ≤ 40 kg/m2, 20–40 years) with PCOS were recruited. Patients were randomized to receive 1,000 mg/day quercetin or placebo for 12 weeks. Resistin plasma concentration and gene expression in peripheral blood mononuclear cells, parameters of glucose homeostasis, circulatory testosterone, luteinizing hormone (LH), and sex hormone‐binding globulin, and anthropometries were assessed at baseline and at the end of the study. Following supplementation, quercetin significantly decreased resistin concentration (2.07 ± 0.23 vs. 2.88 ± 0.40 ng/ml, p < 0.001) and mRNA level (0.64 ± 0.58 vs. 1 ± 0.56 fold change, p = 0.008), compared with placebo group. Moreover, testosterone (0.72 ± 0.15 vs. 0.76 ± 0.12 ng/ml, p = 0.001) and LH (8.05 ± 2.88 vs. 8.77 ± 1.99 mIU/ml, p = 0.035) concentrations were significantly lower in quercetin compared with placebo group. Fasting blood glucose (p < 0.001), insulin (p = 0.02), and homeostatic model assessment of insulin resistance (p = 0.009) decreased within the quercetin group; however, no significant differences were observed compared with the placebo group (p = 0.074, p = 0.226, p = 0.22, respectively). Quercetin supplementation decreased resistin plasma levels and gene expression, and testosterone and LH concentration in overweight or obese women with PCOS.