Summary:
Chronic inflammation has been linked to both physical and mental health conditions. While acute inflammation is a normal immune response that supports healing after injury or infection, chronic inflammation may contribute to the development of illnesses such as cardiovascular disease, cancer, autoimmune conditions, and cognitive decline. Research has also identified associations between chronic inflammation and mental health disorders including depression, bipolar disorder, schizophrenia, and anxiety. Stress appears to play an important role in this relationship, as chronic stress can activate the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis, increasing the production of inflammatory cytokines. Due to growing evidence linking inflammation to mental health, researchers have increasingly examined lifestyle approaches that may reduce inflammation. Anti-inflammatory dietary patterns, particularly the Mediterranean and DASH diets, have received attention because they emphasise foods such as fruits, vegetables, legumes, nuts, whole grains, olive oil, and omega-3-rich fish. This study was a review of randomised controlled trials and systematic evidence syntheses examining anti-inflammatory diets and mental health outcomes. A total of 42 randomised controlled trials and 23 systematic evidence reviews were included. Most dietary interventions were based on the Mediterranean diet. Across the randomised trials, the majority reported significant improvements in at least one mental health outcome following anti-inflammatory dietary interventions. Improvements were consistently observed for depressive symptoms, while findings for anxiety, stress, mood, and quality of life were less consistent. Systematic reviews also reported positive associations between anti-inflammatory dietary patterns and reduced depression risk or symptom severity. Overall, this review found that anti-inflammatory dietary patterns, particularly the Mediterranean diet, may improve depressive symptoms. However, further research using longer follow-up periods and a larger sample size is required to better understand this relationship.
Abstract:
Background: Inflammation has been proposed as a biological pathway linking diet to mental health. Anti-inflammatory dietary patterns, including the Mediterranean and DASH diets, may reduce systemic inflammation and thereby influence mental health outcomes. However, evidence across study designs has not been comprehensively synthesized.
Objective: This scoping review aimed to identify randomized controlled trials (RCTs) and systematic evidence syntheses to summarize the effects of anti-inflammatory dietary interventions or patterns on mental health outcomes in adults. Methods: Searches were conducted in scientific databases through February 2025. Eligible RCTs included adult participants receiving an anti-inflammatory dietary intervention with reported mental health outcomes. Eligible systematic evidence syntheses included systematic reviews with or without meta-analysis, scoping reviews, and umbrella reviews examining associations between anti-inflammatory diets and mental health. Article screening and review were conducted in duplicate, and data extraction followed standardized procedures appropriate for each study type.
Results: A total of 21,923 records were identified, of which 42 RCTs and 23 systematic evidence syntheses met the inclusion criteria. Of the 42 RCTs, 28 reported significantly greater improvements in at least one mental health outcome compared with controls following an anti-inflammatory dietary intervention. Most trials evaluated Mediterranean diet-based interventions. Across RCTs, improvements were most consistently observed for depressive symptoms, while findings for anxiety, mood, stress, and quality of life were mixed. Across the 23 systematic evidence syntheses, findings for depression outcomes were generally positive, with multiple reviews reporting inverse associations between adherence to anti-inflammatory dietary patterns and depression risk or symptom severity. Evidence for anxiety outcomes across reviews was more heterogeneous and less consistent.
Conclusion: Anti-inflammatory dietary patterns, particularly the Mediterranean diet, are associated with improvements in depressive symptoms across randomized controlled trials and systematic evidence syntheses, with less consistent findings for anxiety and other mental health outcomes. Benefits were most consistently observed among individuals with existing mental health symptoms. Interpretation is limited by heterogeneity in dietary interventions, multimodal study designs, populations, and outcome measures. Future research using standardized dietary protocols, longer follow-up periods, and biomarker assessment is needed to strengthen causal inference and clarify underlying mechanisms.
Article Publication Date: 13/04/2026
DOI: 10.3389/fnut.2026.1795350
