A systematic review and meta-analysis of the omega-3 fatty acids effects on brain-derived neurotrophic factor (BDNF)

BACKGROUND: Omega-3 fatty acids (omega-3 FAs) have attracted the attention of researchers because of their influence on circulatory levels of brain-derived neurotrophic factor (BDNF). Our objective was to review systematically and Meta-analyze randomized controlled trials (RCTs) to assess the effects of omega-3 FAs supplementation on serum BDNF concentration. METHODS: Scopus, PubMed, Web of Science, and Cochrane Library were systematically searched until April 2023. The Cochrane risk of bias assessment tool was utilized to evaluate the quality of the studies. A random-effects model was employed to estimate the overall effect size of BDNF levels, using the Standard Mean Difference (SMD) and a 95% confidence interval (CI). The heterogeneity among the studies was assessed using chi-squared and I2 statistics. RESULTS: < 0.001). Sub-group analyses revealed similar findings in trials with fewer than 10 weeks, which utilized both animal (fish oil) and herbal (flaxseed) forms of omega-3 supplements with a high daily dosage of 2000mg. CONCLUSION: The present systematic review and meta-analysis indicate the efficacy of omega-3 FAs in increasing the serum concentration of BDNF. Therefore, omega-3 FAs should be prioritized as agents for increasing BDNF in interventions.