Background: New research supports an integrated approach to treating depression, and lifestyle modifications should be a regular component of both preventative and treatment programs. Therefore, in order to investigate the relationship between various antioxidant supplements and depressive status, we carried out a meta-analysis of randomized controlled trials (RCT).

Methods: We thoroughly searched PubMed, Medline, Scopus, and Web of Science databases to screen publications focusing on the effects of antioxidant supplements on depression status. The meta-analysis mainly compared depression scores between groups that received antioxidant supplements and controls. We also pooled studies reporting changes in anxiety status as a secondary outcome.

Results: 52 studies with 4049 participants were eventually identified. The meta-analysis found that the positive effect of antioxidant supplementation, such as magnesium (SMD = 0.16, p = 0.03), zinc (SMD = 0.59, p = 0.01), selenium (SMD = 0.33, p = 0.009), CoQ10 (SMD = 0.97, p = 0.05), tea and coffee (SMD = 1.15, p = 0.001) and crocin (MD = 6.04, p < 0.00001), on depressive status were all significant. And antioxidant supplementation also showed significant improvement in anxiety (SMD = 0.40, p < 0.00001). Subgroup analysis by scale types and countries were performed, and antioxidant supplementation's positive effects on depressive and anxiety states remained significant.

Limitations: This study did not limit the characteristics of the included population, and the diversity of scales also contributed to the heterogeneity.

Conclusion: Intake of antioxidant supplements is associated with improved depression and anxiety states, further affirms the therapeutic potential of antioxidant supplements as adjunctive therapy to conventional antidepressants.