Associations of Plasma Omega-3 Fatty Acid Levels and Reported Fish Oil Supplement Use with Depression and Anxiety: A Cross-Sectional Analysis from the United Kingdom Biobank.

BACKGROUND

The role that marine omega-3 (n-3) polyunsaturated fatty acids (PUFAs) may play in reducing the risk for developing depression and/or anxiety is unclear.

OBJECTIVES

The present study examined the relationships between plasma levels of total omega-3 PUFAs, docosahexaenoic acid (DHA), and the non-DHA ω-3 PUFAs with medical record-documented depression and/or anxiety (both historical and recent, within the last 12 mo) in the United Kingdom Biobank. The associations of these outcomes with the reported use of fish oil supplements (FOS) were also examined.

METHODS

Information from 258,354 participants who had data on plasma ω-3 PUFA levels and all covariates were used for the biomarker-based analyses, and data from 468,145 people who reported FOS use at baseline were used in the latter analysis.

RESULTS

We found that all 3 ω-3 PUFA metrics were inversely associated with a history of both depression and anxiety. Specifically, risk for the former outcome was between 15% and 33% lower in Q5 compared with Q1, and for the latter outcome, between 19% and 22% lower comparing Q5 with Q1. Risk for recent depression was 29% and 32% lower (Q5 compared with Q1) for total ω-3 PUFAs and for non-DHA, respectively. FOS use was associated with a 9%-10% lower risk for a history of depression and anxiety, respectively, and a 20% lower risk for recent anxiety.

CONCLUSIONS

We found evidence that higher levels of ω-3 PUFAs may play a protective role in depression and anxiety.