Long Oral Presentation Nutrition Society of Australia 50th Annual Scientific Meeting 2026

The association of 15 dietary exposures with risk of depression: a burden of proof study for the global burden of disease lifestyle and mental disorders taskforce (146998)

Deborah N Ashtree 1 , Rebecca Orr 1 , Emma Todd 1 , Sarah Gauci 1 , Melissa M Lane 1 , Felice N Jacka 1 , Nikki DeCleene 2 , Damian Santomauro 2 3 4 , Adrienne O'neil 1
  1. Deakin Food and Mood Centre, Deakin Institute for Mental and Physical Health and Clinical Translation (Deakin IMPACT), Deakin University, Geelong, VIC, Australia
  2. Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington, United States
  3. Queensland Centre for Mental Health Research, Wacol, Queensland, Australia
  4. Faculty of Medicine, School of Public Health, University of Queensland, Herston, Queensland, Australia

Diet is a key, actionable risk factor for depression (1), yet it is currently not included in the Global Burden of Disease study (GBD) as a contributor to depression, limiting global prevention policy. The Global burden of disease Lifestyle And mental Disorders (GLAD) Taskforce was established to generate the robust, GBD-aligned evidence needed to enable inclusion of dietary exposures as risks for depression in the GBD and subsequent depression prevention policies globally (2). We 1) recruited international cohort studies to participate in the GLAD initiative; 2) developed and implemented a harmonised protocol to estimate the risk of depression attributable to the GBD-defined dietary exposures (3) of fruits, vegetables, legumes, whole grains, nuts and seeds, milk, fibre, calcium, seafood omega-3, polyunsaturated fats, red meat, processed meat, sugar-sweetened beverages, trans-fatty acids, and sodium; 3) conducted a systematic review to identify additional relevant studies not participating in GLAD; and 4) meta-analysed the risk of depression attributable to diet using the GBDs burden-of-proof (BoP) methods (4). The BoP incorporated measures of heterogeneity and bias to produce a 1–5-star rating regarding the evidence for an association between each dietary exposure and depression. A total of 22 studies from 12 countries participated in the GLAD project from 2021-2026 (n = 280,793; k varied by dietary exposure). Sugar-sweetened beverage intake was the dietary exposure with the most consistent ‘harmful’ association (12 out of 19 studies), with preliminary pooled risk ratios (RR) indicating each 375 ml/day intake was associated with an 18% increased risk of depression (RR = 1.18; 95% confidence interval (95%CI) = 1.08 to 1.30). Fibre intake had the most consistent evidence as a ‘protective’ dietary exposure (12 out of 19 studies) – preliminary pooled RR found an 8% reduced risk of depression per 30 gram/day intake (RR = 0.92; 95%CI = 0.90 to 0.94). BoP analyses confirm these results, therefore providing the necessary evidence to incorporate dietary risks for depression in the GBD. For example, the BoP identified a 2-star relationship between wholegrain consumption and lower risk of depression (RR = 0.92, 95% uncertainty interval = 0.85 to 0.99). This work provides the first GBD-aligned BoP synthesis of dietary risks for depression, producing policy-relevant estimates to inform prevention-focused mental health guidelines.

  1. Firth J et al. (2020) World Psychiatry 19, 360.
  2. Ashtree DN et al. (2025) JMIR Res Protoc 14, e65576.
  3. Brauer M et al. (2024) The Lancet 403, 2162-2203.
  4. Zheng P et al. (2022) Nat Med 28, 2038-2044.