Department of Clinical Nutrition, School of Nutrition and Food Science, Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
J Trace Elem Med Biol. 2021 Jul;66:126753. doi: 10.1016/j.jtemb.2021.126753. Epub 2021 Apr 1.
Zinc in one of the most abundant trace minerals in human body which is involved in numerous biological pathways and has variety of roles in the nervous system. It has been assumed that zinc exerts its role in nervous system through increasing brain derived neurotrophic factor (BDNF) concentrations.
Present meta-analysis was aimed to review the effect of zinc supplementation on serum concentrations of BDNF.
Four electronic databases (Pubmed, Scopus, Web of Science, Embase) were searched for identifying studies that examined BDNF levels prior and after zinc supplementation up to May 2020. According to the Cochrane guideline, a meta-analysis was performed to pool the effect size estimate (Hedges' test) of serum BDNF across studies. Risk of publication bias was assessed using a funnel plot and Egger's test.
Five studies were eligible and 238 participants were included. These studies enrolled subjects with premenstrual syndrome, diabetic retinopathy, major depression disorder, overweight/obese and obese with mild to moderate depressive disorders. Zinc supplementation failed to increase blood BDNF concentrations with effect size of 0.30 (95 % CI: -0.08, 0.67, P = 0.119). Funnel plot did not suggest publication bias.
Zinc supplementation may not significantly increase BDNF levels. However, the small number of included articles and significant heterogeneity between them can increase the risk of a false negative result; therefore, the results should be interpreted with caution.
锌是人体中最丰富的微量元素之一，参与众多生物途径，在神经系统中具有多种作用。人们认为锌通过增加脑源性神经营养因子（BDNF）的浓度来发挥其在神经系统中的作用。
本次荟萃分析旨在回顾锌补充对血清 BDNF 浓度的影响。
四个电子数据库（Pubmed、Scopus、Web of Science、Embase）被检索以确定在截至 2020 年 5 月之前检查锌补充前后 BDNF 水平的研究。根据 Cochrane 指南，对研究之间的血清 BDNF 的效应大小估计（Hedges 检验）进行荟萃分析。使用漏斗图和 Egger 检验评估发表偏倚的风险。
五项研究符合条件，共有 238 名参与者入选。这些研究纳入了经前期综合征、糖尿病视网膜病变、重度抑郁症、超重/肥胖和伴有轻度至中度抑郁障碍的肥胖患者。锌补充未能增加血液 BDNF 浓度，其效应大小为 0.30（95 % CI：-0.08，0.67，P = 0.119）。漏斗图未提示发表偏倚。
锌补充可能不会显著增加 BDNF 水平。然而，纳入的文章数量较少且它们之间存在显著的异质性，这可能会增加假阴性结果的风险；因此，结果应谨慎解释。
