Is EPA or DHA Better for Depression?
A recent meta-analysis demonstrated that it does indeed matter whether EPA (eicosapentanoic acid) or DHA (docosahexanoic acid) is in your omega-3 fatty acid supplement. A total of 21 studies using greater than 50% EPA or pure EPA in the supplement showed significant reductions in depressive symptoms. On the contrary, symptoms of depression were not reduced in 7 studies that used only DHA or more than 50% DHA. Unfortunately, there was evidence of publication bias towards positive trials with good results, and heterogeneity in the trials, limiting their ultimate applicability. Were the authors studying DHA just more honest? That seems unlikely, as there were multiple groups publishing the results. Still, this study provided some evidence that the content of your omega-3 supplements does matter, and that EPA might be better for depression. (J Am Coll Nutr. 2009 Oct;28(5):525-42.)
