An Umbrella Review of Systematic Reviews and Meta-analyses of Randomized Controlled Trials Investigating the Effect of Curcumin Supplementation on Lipid Profiles

Dyslipidemia is a major risk factor for atherosclerotic cardiovascular disease (ASCVD), and curcumin may help improve lipid metabolism. This umbrella review and updated meta-analysis assessed the effects of curcumin supplementation on lipid profiles. Electronic databases (Medline, Scopus, Cochrane, and Google Scholar) were searched through March 31, 2023, without language restrictions. Two independent authors selected eligible randomized controlled trials (RCTs) involving curcumin supplementation compared with placebo, measuring total cholesterol (TC), low-density-lipoprotein cholesterol (LDL-c), high-density-lipoprotein cholesterol (HDL-c), and triglyceride (TG) levels. This study identified 26 systematic reviews and meta-analyses (MAs) that met the inclusion criteria for the umbrella review. Of these, 53 RCTs, with a corrected coverage area of 9.76% indicating a moderate degree of overlap, were included for re-pooling. Additionally, this study found 19 more RCTs, bringing the total number of studies for the updated MAs to 72. Curcumin significantly reduced TC, LDL-c, and TG, with mean differences (MDs) of -7.76 mg/dL (95% CI: -11.29, -4.22; I2 = 97%), -5.84 mg/dL (95% CI: -11.63, -0.05; I2 = 98%), and -13.15 mg/dL (95% CI: -17.31, -8.98; I2 = 94%), respectively, and increased HDL-c by 2.4 mg/dL (95% CI: 1.22, 3.57; I2 = 94%). The reductions in LDL-c and TG reached the minimally clinically important differences (MCIDs). However, the reduction in TC and increase in HDL-c did not meet their respective MCIDs. Subgroup analysis showed greater lipid improvements in patients with metabolic-related diseases, particularly type 2 diabetes. Enhanced bioavailability forms of curcumin, supplementation for at least 8 weeks, and exercise yielded additional benefits. The study confirmed that curcumin has an anti-lipidemic effect on patients with noncommunicable diseases. A form of curcumin with enhanced bioavailability is preferred, and supplementation for at least 8 weeks, along with exercise, may be used as an accessible approach to reduce the risk of ASCVD. PROSPERO registration no. CRD42023415577.