The meta-analysis, published in The American Journal of Clinical Nutrition, reveals that several key glycemic indicators are significantly reduced by zinc supplementation in subjects with diabetes.
Researchers from Zhejiand University School of Medicine, in Hangzhou, analysed 32 published randomised placebo-controlled interventions from 36 publications from PubMed, Embase, and the Cochrane Library, involving a total of 1700 participants in 14 countries.
Although many studies have shown that low zinc status is associated with diabetes, the putative effects of zinc supplementation on glycemic control are inconclusive. The aim of this meta-analysis was to assess the effects of zinc supplementation on glycemic control in subjects who either have diabetes or have a high risk of developing diabetes
Overall, compared with their respective control groups, the subjects in the zinc-supplementation group had a statistically significant reduction in fasting glucose, two hour postprandial glucose, fasting insulin, homeostasis model assessment for insulin resistance, glycated hemoglobin, and high-sensitivity C-reactive protein concentrations.
Moreover, subgroup analyses revealed that the effects of zinc supplementation on FG are significantly influenced by diabetic status and the formulation of the zinc supplement.
According to the report, a growing body of evidence supports an association between hyperglycemia and zinc metabolism. For example, many studies have provided evidence that low zinc status is associated with impaired insulin secretion, decreased insulin sensitivity, and increased inflammatory biomarkers.
Previous studies have also revealed significant differences between diabetic patients and healthy subjects with respect to blood concentrations of zinc, and patients with low zinc concentrations are more likely to have had diabetes for a longer time, have poorer glucose control, and have reduced pancreatic β cell function.
Results from previous meta-analyses suggest that zinc supplementation may exert a favourable effect on several plasma lipid parameters and some analyses have revealed that fasting glucose and glycated hemoglobin, are reduced following zinc supplementation.
However, due to the limited amount of available data, the effects of zinc supplementation with respect to preventing or treating diabetes are currently inconclusive.
In recent years, a growing number of well-designed randomised controlled trials have focused on examining the putative effects of zinc supplementation on obesity, metabolic syndrome, prediabetes, and diabetes, thus providing important data regarding the relation between zinc supplementation and diabetes prevention and management.
However these studies varied with respect to several parameters, including sample size, the subjects’ health status, and the dose and efficacy of the zinc supplementation, thereby leading to inconsistencies among studies.
Source: The American Journal of Clinical Nutrition
Authors: Wag. X., Wu. W., et al.
“Zinc supplementation improves glycemic control for diabetes prevention and management: a systematic review and meta-analysis of randomized controlled trials”