A meta-analysis published in Psychosomatic Medicine indicates healthful diets reduce depressive symptoms. Researchers reviewed 16 studies that reported effects of healthful dietary interventions on depression and anxiety.
Results: diets that reduced fatty foods and increased fruit and vegetable consumption led to significantly decreased symptoms of depression, compared to control diets. Increased consumption of fiber, minerals and vitamins from plant foods are indicating improved pathways related to depression, including inflammation and oxidative stress.
Dirth J, Marx W, Dash S, et al. The effects of dietary improvement on symptoms of depression and anxiety: a meta-analysis of randomized controlled trials. Psychosom Med. Published online February 5, 2019.