Atherosclerosis 210 (2010) 344–352 Contents lists available at ScienceDirect Atherosclerosis journal homepage: www.elsevier.com/locate/atherosclerosis Review Effects of zinc on plasma lipoprotein cholesterol concentrations in humans: A meta-analysis of randomised controlled trials Meika Foster a , Peter Petocz b , Samir Samman a,* a Discipline of Nutrition and Metabolism, School of Molecular and Microbial Biosciences, University of Sydney NSW 2006, Australia b Department of Statistics, Macquarie University, NSW 2109, Australia article info Article history: Received 13 June 2009 Received in revised form 18 November 2009 Accepted 24 November 2009 Available online 29 November 2009 Keywords: Meta-analysis Lipoproteins Cardiovascular disease Zinc abstract 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 supple- mentation 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 triglyc- eride concentrations. Plasma zinc concentrations increased significantly (+2.42 ± 0.25 mol/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. Conclusion: 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. © 2009 Elsevier Ireland Ltd. All rights reserved. Contents 1. Introduction .......................................................................................................................................... 345 2. Methods .............................................................................................................................................. 345 2.1. Search strategy ............................................................................................................................... 345 2.2. Study selection ............................................................................................................................... 345 2.3. Data extraction ............................................................................................................................... 345 2.4. Quality assessment ........................................................................................................................... 345 2.5. Statistical analysis ............................................................................................................................ 347 3. Results ................................................................................................................................................ 347 3.1. Effects of zinc supplementation on total cholesterol concentrations ....................................................................... 347 3.2. Effects of zinc supplementation on plasma LDL cholesterol concentrations ................................................................ 347 3.3. Effects of zinc supplementation on plasma HDL cholesterol concentrations ............................................................... 348 3.4. Effects of zinc supplementation on plasma triglyceride concentrations .................................................................... 348 3.5. Effects of zinc supplementation on plasma zinc concentrations ............................................................................ 349 3.6. Assessment of bias ........................................................................................................................... 349 4. Discussion ............................................................................................................................................ 350 References ........................................................................................................................................... 351 * Corresponding author at: Discipline of Nutrition and Metabolism, School of Molecular and Microbial Biosciences, Biochemistry and Microbiology Building, G08, The University of Sydney, NSW 2006, Australia. Tel.: +61 2 9351 2476; fax: +61 2 9351 6022. E-mail address: s.samman@usyd.edu.au (S. Samman). 0021-9150/$ – see front matter © 2009 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.atherosclerosis.2009.11.038