Omega-3 fish oil has a mixed but generally positive record when it comes to supporting optimal mood health.
Much of the positive evidence stems from studies that used only omega-3 EPA, which is one of the two omega-3 fatty acids in fish oil, the other being DHA.
An evidence review from Britain supports the greater efficacy of EPA, versus DHA (Martins JG 2009).
But putting aside each of these two omega-3s’ potential for preventing and treating depression, there are sound biochemical reasons to consider both important to general mood support … see “Omega-3s Show New Benefit for Mood Health” and “Omega-3s Display More Brain-Mood Benefits”.
As to the clinical evidence, an expert panel appointed by the American Psychiatric Association (APA) in 2006 found the evidence available at the time generally positive … see “Top Psych Panel Says Omega-3s Deter Depression, Bipolar Disorder”.
The following year witnessed the publication of two evidence reviews. A panel in the UK declined to advise doctors to prescribe omega-3s (see “British Panel Gives Docs a Bum Steer”). And while a Taiwanese team also declined to advise doctors to prescribe omega-3s, they came to a more positive conclusion regarding omega-3s’ efficacy (see “Omega-3 Mood Benefits Get More Backing”).
Last year, an American team issued a “meta-analysis” of the best clinical studies – funded by the U.S. National Institutes of Health and conducted by researchers from UCLA and the University of Illinois – which echoed the positive opinions issued by the 2006 APA panel.
As the authors of that 2010 analysis wrote, “… patients taking omega-3 with either EPA or a combination of EPA and DHA experienced clear antidepressant benefits …” (see “Mood Benefits of Omega-3s Affirmed”.
Significantly, the 2010 evidence review encompassed a larger body of high-quality clinical evidence than was available to the authors of the earlier analyses.
Nonetheless, it will take positive results from several large, well-controlled trials before mainstream medicine adopts omega-3 fish oil as a standard tool for mood support and enhancement.
In the meantime, small studies continue to emerge, whose generally positive outcomes should encourage funding of such large studies.
Iranian trial finds omega-3 fish oil effective vs. placebo
In 2009, a joint Anglo-Iranian team reported their clinical finding that omeg-3 EPA from fish oil cut depression ratings by 50 percent.
That improvement matched the gains measured among participants who took fluoxetine, the generic form of Prozac (see “Omega-3s Affirmed as Mood Lighteners”).
Now another small clinical trial from Iran supports a positive view of the potential for omega-3s to boost mood health.
Researchers from the Tehran University of Medical Sciences recruited 66 people over age 65 – who’d previously been diagnosed with mild to moderate depression – for a double-blind, randomized, placebo-controlled clinical trial.
The participants were randomly assigned to take either one 1000mg capsule of fish oil (one-gram, providing 300 mg of EPA plus DHA) or an identical-looking placebo oil capsule daily for six months.
Both groups took a standard test for depression and mood before and after the trial.
After adjusting the results to account for known influences on mood (e.g., cholesterol profile, body mass index, and thyroid health) the authors concluded that the fish oil group displayed a statistically significant improvement in depression rating scores versus the placebo group.
The Iranian authors expressed their conclusion this way: “… treatment with omega-3s was clinically more effective ... low-dose omega-3s had some efficacy in the treatment of mild to moderate depression in elderly participants.”
At this point one would have to wonder why any physician or layman would not consider fish oil a “no brainer” for safe, natural mood support … either alone or, as needed, in conjunction with pharmaceuticals.
Freeman MP, Hibbeln JR, Wisner KL, Davis JM, Mischoulon D, Peet M, Keck PE Jr, Marangell LB, Richardson AJ, Lake J, Stoll AL. Omega-3 fatty acids: evidence basis for treatment and future research in psychiatry. J Clin Psychiatry. 2006 Dec;67(12):1954-67. Review.
Freeman MP. Omega-3 fatty acids in psychiatry: a review. Ann Clin Psychiatry. 2000 Sep;12(3):159-65. Review.
Lin PY, Su KP. A meta-analytic review of double-blind, placebo-controlled trials of antidepressant efficacy of omega-3 fatty acids. J Clin Psychiatry. 2007 Jul;68(7):1056-61.
Martins JG. EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials. J Am Coll Nutr. 2009 Oct;28(5):525-42. Review.
Parker G, Gibson NA, Brotchie H, Heruc G, Rees AM, Hadzi-Pavlovic D. Omega-3 fatty acids and mood disorders. Am J Psychiatry. 2006 Jun;163(6):969-78. Review. Erratum in: Am J Psychiatry. 2006 Oct;163(10):1842.
Peet M, Stokes C. Omega-3 fatty acids in the treatment of psychiatric disorders. Drugs. 2005;65(8):1051-9. Review.
Tajalizadekhoob Y, Sharifi F, Fakhrzadeh H, Mirarefin M, Ghaderpanahi M, Badamchizade Z, Azimipour S. The effect of low-dose omega 3 fatty acids on the treatment of mild to moderate depression in the elderly: a double-blind, randomized, placebo-controlled study. Eur Arch Psychiatry Clin Neurosci. 2011 Feb 12. [Epub ahead of print]
Young G, Conquer J. Omega-3 fatty acids and neuropsychiatric disorders. Reprod Nutr Dev. 2005 Jan-Feb;45(1):1-28. Review.