Effects of zinc on plasma lipoprotein cholesterol concentrations in humans: a meta-analysis of randomised controlled trials.
BACKGROUND
Studies in humans and animals suggest that zinc has the potential to affect lipoprotein metabolism and hence impact cardiovascular disease risk.


METHODS
A meta-analysis of controlled clinical trials was conducted to determine the effect of zinc supplementation on plasma cholesterol and triglyceride concentrations in humans. Potentially relevant studies were identified from a literature search covering the period 1980-2008 (inclusive), and additional citation searches.


RESULTS
Thirty three interventions (n=14,238 subjects) were included in the random effects meta-analysis. No overall significant effects of zinc supplementation were observed for plasma cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol or plasma triglyceride concentrations. Plasma zinc concentrations increased significantly (+2.42+/-0.25 micromol/L, P<0.001; n=14,047). Secondary analyses in individuals classified as healthy revealed that zinc supplementation is associated with a significant decrease in plasma HDL cholesterol concentrations (-0.10+/-0.02 mmol/L, P<0.001; n=13,215), equivalent to a 7% decrease from baseline.


CONCLUSIONS
No effect of zinc supplementation on plasma lipoproteins was detected in the overall analysis. In individuals classified as healthy, zinc supplementation is associated with a decrease in HDL cholesterol concentrations and thus contributes to an increased risk of coronary heart disease.
Foster
Meika
M
Discipline of Nutrition and Metabolism, School of Molecular and Microbial Biosciences, University of Sydney NSW 2006, Australia.
Petocz
Peter
P
Samman
Samir
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002318:Cardiovascular Diseases / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D014280:Triglycerides / Q000097:blood; D015032:Zinc / Q000737:chemistry / Q000494:pharmacology*
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D015032:Zinc