Zinc supplementation may increase brain-derived neurotrophic factor Original paper

In this meta-analysis of randomized controlled trials, zinc supplementation increased serum levels of brain-derived neurotrophic factor. However, this result was based on only 4 studies of variable quality.

This Study Summary was published on January 31, 2023.


Brain-derived neurotrophic factor (BDNF) is a protein found in the brain, where it is involved in the formation, survival, and growth of neurons. As a result, BDNF is believed to help support and maintain normal cognitive function.[1]

Higher synaptic levels of zinc are thought to increase BDNF through a few possible mechanisms. Notably, zinc is necessary for the function of matrix metalloproteinase 9 (MMP-9), one of the enzymes that generates BDNF from its precursor proBDNF.[2] Can zinc supplementation therefore increase BDNF levels?

The study

This meta-analysis of 4 randomized controlled trials examined the effect of zinc supplementation on levels of BDNF. A total of 185 participants were included (ages 18– 55). Each trial studied different populations, namely, people with major depressive disorder (MDD), young women with premenstrual syndrome* (PMS), people with diabetic retinopathy, and people with overweight or obesity.

Three trials lasted 84 days, and 1 trial lasted 90 days. The daily dosage of zinc was 30 mg in 3 trials and 25 mg in 1 trial. Three of the trials used a placebo comparator.

The outcomes were serum levels of BDNF (4 trials) and serum levels of zinc (3 trials). Of the trials, 2 were considered good quality and 2 were considered poor quality.

The results

Zinc supplementation increased serum levels of both BDNF and zinc.

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This Study Summary was published on January 31, 2023.


  1. ^Siresha Bathina, Undurti N DasBrain-derived neurotrophic factor and its clinical implicationsArch Med Sci.(2015 Dec 10)
  2. ^Frazzini V, Granzotto A, Bomba M, Massetti N, Castelli V, d'Aurora M, Punzi M, Iorio M, Mosca A, Delli Pizzi S, Gatta V, Cimini A, Sensi SLThe pharmacological perturbation of brain zinc impairs BDNF-related signaling and the cognitive performances of young mice.Sci Rep.(2018-Jun-27)