Lipid profile and glucose changes after supplementation with astaxanthin: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION Many studies have shown that oral supplementation with astaxanthin may be a novel potential treatment for inflammation and oxidative stress in cardiovascular diseases, but evidence of the effects on lipid profile and glucose is still inconclusive. Therefore, we performed a meta-analysis to evaluate the efficacy of astaxanthin supplementation on plasma lipid and glucose concentrations. MATERIAL AND METHODS The search included PubMed, Cochrane Library, Scopus, and EMBASE (up to November 27, 2014) to identify randomized controlled trials (RCTs) investigating the effects of astaxanthin supplementation on lipid profile and glucose levels. Two independent reviewers extracted data on study characteristics, methods and outcomes. RESULTS Seven studies meeting inclusion criteria with 280 participants were selected for this meta-analysis; 163 participants were allocated to the astaxanthin supplementation group and 117 to the control group. A random-effect meta-analysis of data from 7 RCTs (10 treatment arms) did not show any significant effect of supplementation with astaxanthin on plasma concentrations of total cholesterol (weighted mean difference (WMD): -1.52 mg/dl, 95% CI: -8.69 to -5.66, p = 0.679), LDL-C (WMD: +1.25 mg/dl, 95% CI: -6.70 to +9.21, p = 0.758), HDL-C (WMD: +1.75 mg/dl, 95% CI: -0.92 to +4.42, p = 0.199), triglycerides (WMD: -4.76 mg/dl, 95% CI: -21.52 to +12.00, p = 0.578), or glucose (WMD: -2.65 mg/dl, 95% CI: -5.84 to +0.54, p = 0.103). All these effect sizes were robust, and omission of any of the included studies did not significantly change the overall estimate. CONCLUSIONS This meta-analysis of data from 10 RCT arms did not indicate a significant effect of supplementation with astaxanthin on plasma lipid profile, but a slight glucose-lowering effect was observed. Further, well-designed trials are necessary to validate these results.