Healthy diets linked to lower depression risk in adults, systematic review finds

Adults who eat healthier diets may be less likely to experience depression, according to a systematic review of observational studies published in BMC Public Health. The review, which followed PRISMA reporting guidelines, synthesized research on the associations between dietary patterns and common mental disorders—depression and anxiety—in adult populations.

Researchers searched six electronic databases through 2024, with no restriction on the initial year of publication, and screened the results using Rayyan Web software. Two reviewers independently selected and extracted data, with disagreements resolved by a third reviewer. Methodological quality and risk of bias were assessed with Joanna Briggs Institute tools, and findings were presented in tables, text, and forest plots.

In total, 26 studies met the inclusion criteria. Twenty of them examined depression, five examined anxiety, and one assessed both conditions. The number of participants in the individual studies ranged from 135 to 14,541, giving the review a broad evidence base drawn from observational research designs.

The review’s central finding was an inverse association between healthy dietary patterns and common mental disorders. This pattern was most evident for depression, which had the largest number of available articles in the literature, with twenty studies addressing it.

Evidence regarding anxiety was far more limited and inconsistent, a limitation the authors attribute directly to the small number of available studies. With only five studies examining anxiety and one covering both conditions, the reviewers concluded that no firm conclusions could be drawn about how dietary patterns relate to anxiety in adults.

The association between unhealthy dietary patterns and common mental disorders remained unclear, according to the review. High heterogeneity across the study results prevented the researchers from reaching a consistent conclusion in this area. Mixed dietary patterns and mixed-alcoholic patterns were also not consistently associated with the common mental disorders analyzed.

The authors caution that healthy dietary patterns may be associated, particularly, with a lower frequency of depression, and that more robust future studies are needed to better understand these associations.

Nevertheless, the reviewers conclude that the results reinforce the importance of diet as a key component of mental health promotion strategies. The article, authored by Elaine Valdna Oliveira dos Santos, Lucas de Almeida Moura, Camila Valdejane Silva de Souza, Gustavo Borsalino Ferreira, Angela Cristina Bizzotto Trude, and Dirce Maria Lobo Marchioni, was published as an open access systematic review on 27 October 2026.

Subject of Research: Associations between dietary patterns and common mental disorders in adults

Article Title: Dietary patterns and adult mental health: a systematic review of observational studies

Article References: dos Santos, E. V. O., de Almeida Moura, L., de Souza, C. V. S., Ferreira, G. B., Trude, A. C. B., & Marchioni, D. M. L. (2026). Dietary patterns and adult mental health: a systematic review of observational studies. BMC Public Health. https://doi.org/10.1186/s12889-026-29187-y

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29187-y

Keywords: dietary patterns, mental health, depression, anxiety, systematic review, observational studies, BMC Public Health, PRISMA, adults, nutrition, risk of bias, Dietary