Role of dietary factors in the prevention and treatment for depression: an umbrella review of meta-analyses of prospective studies

The role of diet in depression is becoming increasingly acknowledged. This umbrella review aimed to summarize comprehensively the current evidence reporting the effects of dietary factors on the prevention and treatment of depression. PubMed, Embase, and the Cochrane Library were searched up to June 2021 to identify relevant meta-analyses of prospective studies. Twenty-eight meta-analyses, with 40 summary estimates on dietary patterns ( n = 8), food and beverages ( n = 19), and nutrients ( n = 13) were eligible. The methodological quality of most meta-analyses was low (50.0%) or very low (25.0%). Quality of evidence was moderate for inverse associations for depression incidence with healthy diet [risk ratio (RR): 0.74, 95% confidential interval (CI), 0.48–0.99, I 2 = 89.8%], fish (RR: 0.88, 95% CI, 0.79–0.97, I 2 = 0.0%), coffee (RR: 0.89, 95% CI, 0.84–0.94, I 2 = 32.9%), dietary zinc (RR: 0.66, 95% CI 0.50–0.82, I 2 = 13.9%), light to moderate alcohol (