Effects of Copper Supplementation on Blood Lipid Level: a Systematic Review and a Meta-Analysis on Randomized Clinical Trials

Studies have evaluated the effect of copper (Cu) supplementation on blood lipid level. We therefore investigated whether the supplement of Cu on blood lipid level will have an impact in a meta-analysis on randomized controlled trials (RCTs). Literature search was conducted in Scopus, PubMed, Web of Science, and Cochrane Library (from database to January 2020). Randomized controlled trials of Cu supplementation on blood lipid level were retrieved according to the requirements of systematic review, and the quality of the included research was evaluated. Then the meta-analysis was performed. Data from 5 trials representing 176 participants were examined. Pooled mean net change in total cholesterol (TC) (standard mean difference(SMD) [95% CI] = - 0.05 [- 0.52, 0.43]), low density lipoprotein cholesterol (LDL-C) (SMD [95% CI] = 0.22 [- 0.46, 0.89]), and high density lipoprotein cholesterol (HDL-C) (SMD [95% CI] = 0.18 [- 0.14, 0.49]) for those treated with Cu supplementation had no significant difference when compared with control. Cu supplementation has not affected blood lipids in the result of meta-analysis. More research is needed to determine if this pattern will apply broadly.