The effects of curcumin supplementation on endothelial function: A systematic review and meta-analysis of randomized controlled trials

Impaired endothelial function is an important risk factor for cardiovascular disease (CVD). Curcumin supplementation might be an appropriate approach to decrease the complications of CVD. Randomized controlled trials assessing the effects of curcumin supplementation on endothelial function were included. Two independent authors systematically searched online database including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science with no time restriction. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. Between-study heterogeneities were estimated using the Cochran's Q test and I-square (I-2) statistic. Data were pooled using a random-effects model, and weighted mean differences (WMDs) were considered as the overall effect sizes. Ten studies with 11 effect sizes were included. We found a significant increase in flow-mediated dilation (FMD) following curcumin supplementation (WMD: 1.49; 95% CI [0.16, 2.82]). There was no effect of curcumin supplement on pulse wave velocity (PWV; WMD: -41.59; 95% CI [-86.59, 3.42]), augmentation index (Aix; WMD: 0.71; 95% CI [-1.37, 2.79]), endothelin-1 (ET-1; WMD: -0.30; 95% CI [-0.96, 0.37]), and soluble intercellular adhesion molecule-1 (sICAM-1; WMD: -10.11; 95% CI [-33.67, 13.46]). This meta-analysis demonstrated the beneficial effects of curcumin supplementation on improving FMD, though it did not influence PWV, Aix, Et-1, and sICAM-1.