Journal of Advances in Medicine and Medical Research

Aims: The present systematic review and meta-analysis aims to synthesize current observational evidence on the association between ultra-processed food (UPF) consumption and the risk of depressive symptoms and Major Depressive Disorder (MDD) in adults.

Study Design: Systematic review and meta-analysis of observational studies (cross-sectional and prospective cohorts) conducted in accordance with the PRISMA 2020 guidelines.

Methodology: Data were systematically collected from seven international electronic databases (PubMed/MEDLINE, EMBASE, Cochrane CENTRAL, Scopus, Web of Science, PsycINFO, and LILACS). We included studies on adults (18 years or older) that assessed UPF intake using the NOVA classification. A total of 5 studies meeting the eligibility criteria were included. Pooled Odds Ratios (OR) with 95% Confidence Intervals (CI) were calculated using random-effects models, comparing the highest versus lowest UPF consumption categories.

Results: The analysis encompassed 45,720 adults. Higher UPF consumption was significantly associated with an increased risk of depressive symptoms (OR = 1.76; 95% CI 1.49 to 2.07). The association persisted for the outcome of Major Depressive Disorder (MDD), with an estimated OR of 1.63 (95% CI 1.18 to 2.26). Substantial heterogeneity was observed for both outcomes (I-squared = 84.9% and I-squared = 90.2%, respectively), reflecting variability in study populations and assessment tools.

Conclusion: Elevated ultra-processed food consumption is significantly associated with an increased risk of both depressive symptoms and major depressive disorder in adults. However, given the high heterogeneity and the observational nature of the included studies, causal inference should be interpreted with caution. These findings support the importance of reducing UPF intake as a public health strategy to complement the prevention and management of depression.