Sohaei S, Amani R, Tarrahi MJ, Ghasemi-Tehrani H. The effects of curcumin supplementation on glycemic status, lipid profile and hs-CRP levels in overweight/obese women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled clinical trial. Complement Ther Med. 2019;47:102201.
A 6-week, randomized, double-blind, placebo-controlled clinical trial
The investigators conducted this trial to determine the effect of curcumin supplementation on glycemic status, lipid profile, and high-sensitivity C-reactive protein (hs-CRP) levels in overweight/obese women with polycystic ovary syndrome (PCOS).
Sixty women with PCOS diagnosed by the Rotterdam criteria, aged 18 to 40 years, and with a body mass index (BMI) between 25 and 35 kg/m2 participated in the study. Exclusion criteria included pregnancy, lactation, hyperprolactinemia, thyroid disorder, digestive problems, type 2 diabetes mellitus, congenital adrenal hyperplasia, and overt infection. Use of any of the following in the 3 months preceding the trial also led to exclusion: oral contraceptives, antioxidant supplements, and any intervention that could alter insulin sensitivity, inflammation, or oxidative stress status.
The experimental group (n=30) received 500 mg twice a day standardized turmeric extract 95% (475 mg curcuminoids, containing curcuminoids in the following proportions: 70%–80% curcumin, 15%–20% demethoxycurcumin, 2.5%–6.5% bisdemethoxycurcumin). The control group (n=30) followed the same dosing schedule, but with placebo. Participants were to take the supplements with 2 principal meals.
Primary outcome measures included total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), LDL/HDL ratio, TG/HDL ratio, fasting blood glucose, insulin, homeostasis model of assessment insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), and hs-CRP. Investigators obtained measurements at baseline and week 6.
Fifty-one of the 60 participants completed the study, 27 in the curcumin group and 24 in the placebo group. Three discontinued the intervention due to pregnancy, with the rest withdrawing for unspecified personal reasons. In the experimental group, 3 participants reported gastrointestinal symptoms; otherwise no other adverse effects were noted.
After 6 weeks of intervention, statistically significant changes in serum insulin (P=0.020) and QUICKI (P=0.003), baseline vs study end, occurred in those taking curcumin. All other parameters were nonsignificantly improved, and differences between groups were nonsignificant.
Polycystic ovary syndrome is a complex, multifactorial endocrine disorder that affects up to 18% of reproductive-aged women.1 It is characterized by hyperandrogenism, ovulatory dysfunction, and polycystic ovary morphology, with 2 of the 3 required for diagnosis based on Rotterdam criteria.2 Metabolic derangements, including dysglycemia and dyslipidemia, are highly prevalent among those with PCOS, as is chronic inflammation. Given the predisposition to cardiometabolic disease, treatment goals should include normalizing glycemic, lipid, and inflammatory status.3
There was no mention of pairing curcumin supplementation with either dietary fat or black pepper for enhanced bioavailability.
Metformin, a first-line conventional intervention for PCOS, has been shown to regulate serum glucose and insulin levels, normalize lipids, and reduce inflammation, though not all patients are able to tolerate the medication.4,5 Alternative interventions, such as inositol, have become a topic of interest among researchers, as they yield comparable results with fewer adverse effects.6 Authors of the paper presently in review hypothesized that curcumin would perform similarly, given its anti-inflammatory, antioxidant, and hypolipidemic properties. However, the benefits were limited to improvements only in insulin levels in this study.7
The underwhelming results may be attributable to limitations of the study design. A 6-week interventional period is arguably insufficient time to evaluate efficacy of a supplement. The authors acknowledge this, although they also cite several studies with effects noted within 1 month of initiating curcumin. It was based on these prior results that the trial length was deemed adequate. The authors also acknowledge the likelihood of variability in absorption. They did not perform metabolite testing to assess curcumin levels, though it may have proven useful. The researchers instructed the participants to take supplements with meals to maximize absorption, but there was no mention of pairing curcumin supplementation with either dietary fat or black pepper for enhanced bioavailability.8
Two randomized control trials on curcumin and overweight/obese-type PCOS women have been conducted since this 2019 paper was published. Jamilian et al found significant benefit on metabolic parameters after 12 weeks of 500 mg curcumin daily. They noted improvements in glycemic control, lipid parameters (except triglycerides and very-low-density-lipoprotein [VLDL] cholesterol), weight, and peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression.9 The second study involved 3 months of 1,500 mg TID curcumin and resulted in upregulated activity of proteins and enzymes that serve as modulators of oxidative stress.10
It is evident that the research on curcumin and PCOS is emerging, with the findings of these studies serving as preliminary evidence. Further research is necessary to elucidate its role in altering PCOS pathophysiology, and to determine therapeutic dosing. Given that there are numerous other therapies with well-documented benefits, it may be prudent to reserve the recommendation for those who have concomitant conditions known to respond to curcumin. That aside, encouraging patients to add a few extra dashes of turmeric to their food may be a worthwhile addition to a well-rounded treatment plan, with no expectation of an appreciable effect on the PCOS pathophysiology.