Source: J Clin Psychiatry, Jul 2007; 68(7):1056-61. (meta-analysis)
Research: Evidence has indicated an association between depression and low dietary intake of omega 3 polyunsaturated fatty acids (PUFAs). However, clinical trials examining the therapeutic benefit of omega 3 PUFAs in depression have showed inconsistent results. The goal of this study was to systematically evaluate the antidepressant efficacy of omega 3 PUFAs by conducting a meta-analysis. Researchers reviewed studies from 1966 through August 2006 using the key words: depression, depressive disorder, or mood disorder; and omega 3, EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), poly-unsaturated fatty acid, or fish oil. Ten double-blind, placebo-controlled studies in patients with mood disorders receiving omega 3 PUFAs with the treatment period lasting 4 weeks or longer were included.
Results: When pooling the results of the 10 included studies (N = 329), researchers found a significant antidepressant effect of omega 3 PUFAs. Likewise, omega 3 PUFAs significantly improved depression in patients with clearly defined depression or with bipolar disorder. The dosage of EPA did not change the antidepressant efficacy significantly. Although this meta-analysis showed significant antidepressant efficacy of omega 3 PUFAs, researchers believe it is still premature to validate this finding due to publication bias and heterogeneity. Further, they say large-scale, well-controlled trials are needed to determine the favorable target subjects, therapeutic dose of EPA, and the composition of omega 3 PUFAs in treating depression.