There is increasingly more evidence that omega-3 supplements (aka. fish oil) plays an important role in depression.
In 2010, a group of researchers did a meta-analytic review comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects (1). The result ---Compared with control subjects, the levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total omega-3 (n-3) polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in arachidonic acid (AA) or total omega-6 (n-6) polyunsaturated fatty acids. Thus this implies that omega-3 plays a vital role in pathogenesis of depression. This result is in line with research done back in 1998 and published in Journal of Affective Disorders where researchers noted significantly lower levels of omega-3s in the red blood cell membranes of patients with depression (2).
More recently, a study published in Jan 2016 in Journal of Psychiatric Research shows white matter deficits in depression improved after 6 weeks of fish oil supplementation (3). These therapeutic effects of omega-3 PUFAs may be related to improvements in white matter integrity.
Fish oil is not a definitive treatment of depression, but it may be helpful as an addition to prescribed medications or other treatment. Although more studies are needed to determine exactly what role omega-3s play in depression, it's possible that fish oil supplements high in omega-3s may help lower the risk of depression — and omega-3 has many other health benefits.
1: Lin PY, Huang SY, Su KP. A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression.
Biol Psychiatry. 2010 Jul 15;68(2):140-7. doi: 10.1016/j.biopsych.2010.03.018. Epub 2010 May 10. PubMed
2: Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord. 1998 Mar;48(2-3):149-55. PubMed PMID: 9543204.
3: Chhetry BT, Hezghia A, Miller JM, Lee S, Rubin-Falcone H, Cooper TB, Oquendo MA, Mann JJ, Sublette ME. Omega-3 polyunsaturated fatty acid supplementation and white matter changes in major depression. J Psychiatr Res. 2016 Jan 11;75:65-74.
doi: 10.1016/j.jpsychires.2015.12.007. [Epub ahead of print] PubMed PMID: 26802812.
Dr Nicole Ng (MBBS) is a medical doctor with a passion in women's health and medical research