SIB # 473- Zinc and Serum Lipids

The Study: Effects of Zinc supplementation on serum lipids: a systematic review and meta-analysis

Overview: This paper is a meta analysis of previous studies on the effects of Zinc supplementation on blood lipids with emphasis on the potential prevention of atherogenesis.

Key Points:

 ·         The study reviewed a large number of controlled clinical trials in humans, “that included a Zinc supplement intervention, either alone or in combination with other micronutrients and evaluated effects on serum lipids. 

·         Parameters studied included total cholesterol (TC], triglycerides (TG), LDL cholesterol (LDL-c) and HDL cholesterol (HDL-c). 

·         A total of 24 studies were included in Meta analysis, which included a total of 14,515 participants 

·         The duration of Zinc supplementation in the various studies ranged from 1 month to 7.5 years. 

·         The authors note that previous studies have shown a strong negative association “between the dietary intake of Zinc and the incidence of diabetes and heart disease, as well as several of their associated risk factors including hypertension and hyper-triglyceridemia.” (emphasis ours)

 ·         In general, supplemented subjects in this meta analysis showed mean improvements across all parameters. 

·         Total Cholesterol reduced by of a mean of 10.92 mg/dl. 

·         HDL cholesterol (aka “good” cholesterol) was actually reduced in healthy subjects but conversely was increased in sick subjects.  

·         LDL cholesterol (aka “bad” cholesterol) was reduced by 6.87 mg/dl in the supplemented group. 

·         Triglycerides were also significantly reduced (−10.92 mg/dl) in the supplemented group.   

·         Zinc supplementation produced significant reductions in Total Cholesterol, LDL and Triglycerides “in non-healthy patients and the magnitude of reduction was greater than that in overall analysis.” 

·         Non-healthy patients who were supplemented demonstrated a significant increase in HDL cholesterol as compared to more healthy subjects in the study.

Author’s Conclusions:  The authors conclude that Zinc supplementation demonstrated beneficial effects across all measured plasma lipid parameters. Zinc supplementation significantly reduced total cholesterol, LDL cholesterol and triglycerides as well as increased levels of HDL (“good cholesterol) in less healthy individuals. They further conclude a potential role “to reduce the incidence of atherosclerosis related morbidity and mortality.”

Reviewer's Comments: This is a bit older but still relevant. I found it while looking into Zinc’s potential role in helping to fight viral infections. Although this paper looked at benefits on blood lipids I thought it was interesting in that it highlights the fact that less healthy subjects were consistently more likely to benefit from Zinc supplementation than more “healthy” individuals. Good news for those who need it most. 

Reviewer:  Mark R. Payne DC

Reference: Priyanga Ranasinghe, WS Wathurapatha, MH Ishara, R. Jayawardana, P. Galappatthy, P. Katulanda, and GR Constantine.  Effects of Zinc supplementation on serum lipids: a systematic review and meta-analysis. J. Nutr Metab. 2015; 12: 26. Published online 2015 Aug 4. doi: 10.1186/s12986-015-0023-4

 Link To Article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4523910/