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

Abstract

Context: Dyslipidemia is a major risk factor for atherosclerotic cardiovascular disease (ASCVD), and curcumin may help improve lipid metabolism.

Objective: This umbrella review and updated meta-analysis assessed the effects of curcumin supplementation on lipid profiles.

Data sources: Electronic databases (Medline, Scopus, Cochrane, and Google Scholar) were searched through March 31, 2023, without language restrictions.

Data extraction: 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.

Data analysis: 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.

Results: 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.

Conclusion: 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.

Systematic review registration: PROSPERO registration no. CRD42023415577.

Keywords: atherosclerotic cardiovascular disease; curcumin; lipid; turmeric; umbrella review.