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Influence of omega-3 fatty acids on post-traumatic stress disorder: prospective cohort study and Mendelian randomisation findings

Ming Chen, Hao-Zhang Huang, Yong Liu, Cailan Hou, Shi-Qun Chen

European Journal of Psychotraumatology, 2026

82,391 participants · 1 citation

Abstract

ABSTRACT Background and Objectives: Omega-3 fatty acids have positive effects on mental health. This study aimed to explore the association between plasma omega-3 fatty acid levels and the risk of post-traumatic stress disorder (PTSD). Methods: This study explored the association between plasma omega-3 fatty acid levels and risk of developing PTSD. In total, 82,391 adults from the UK Biobank were included in this study. PTSD screening was performed using a PCL-6 score greater than 13, based on responses to the online mental health questionnaire. Multivariate logistic regression analyses were performed to evaluate the association between omega-3 fatty acid levels and the risk of PTSD. Additionally, a two-sample bidirectional Mendelian randomisation (MR) analysis was used to investigate potential causal relationships. Results: A significant association was found between high omega-3 fatty acid levels and a lower risk of PTSD. For each 1 unit increase in omega-3 fatty acids, the adjusted odds ratio (OR) was 0.75 (p = 9.05E-05); for each 1% increase in total fatty acids, the adjusted OR was 0.95 (p = 4.30E-07). Among the population that has experienced catastrophic traumatic exposure, the results remained consistent. MR analysis indicated that high omega-3 levels and omega-3/total fatty acid ratios were causally linked to a reduced risk of PTSD (per 1 unit increase, OR = 0.99; p = .029; per 1% increase, OR = 0.98; p = .037). Conversely, PTSD was causally associated with lower…

How strong is the evidence?

Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 82,391 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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