New Review of Clinical Trials Supports Benefits of EPA/DHA Omega-3 Supplementation on Depression in Women
Yang, J. et al., Neuropsychiatric Disease and Treatment, 11: 2055-2061, 2015
Dept. of Medical Psychology, Public Health Institute of Harbin, Medical University, Harbin, Republic of China
Depression is considered to have afflicted approximately 1 in 20 people to varying degrees in the previous year. While depression and related anxiety is a significant cause of disability for both genders, the burden of this mental disorder is about 50 % higher in women relative to men. The purpose of the present investigation was to objectively review (via ‘meta-analysis’) the results from previously-published and well-controlled clinical trials wherein the potential effect of daily supplementation with EPA plus DHA in women with depression for relatively short-term intervals was evaluated. The primary outcome measure was the effect of EPA/DHA supplementation on subsequent depression severity as compared to baseline depression scores at initiation of the intervention.
The authors identified eight randomized controlled trials that fulfilled appropriate criteria. In these trials, all women had to be over 18 years of age. The clinical measures of depression severity included various depression rating scales. In the eight trials combined, 182 subjects had been assigned to ‘placebo’ treatment (supplementation lacked EPA/DHA) and 185 had been assigned to daily supplementation with EPA/DHA. The daily doses of EPA plus DHA combined in these various trials ranged from 1.2 to 6.6 grams with all but one having more EPA than DHA. (with an EPA:DHA ratio of approx. 2:1 in 5 of the trials). The duration of supplementation was eight weeks in 7 of the 8 trials and six weeks in one. After appropriate weighting of each trial according to the parameters used, the overall statistical analyses indicated a significant beneficial effect on depressed mood with the combined intake of EPA plus DHA (relative to the ‘placebo’ controls). In summary , the overall reduction on depression due to omega-3 supplementation amounted to 35 % whether EPA/DHA was used as monotherapy or as an augmentation agent (eg., in addition to supportive psychotherapy). The authors stated that ‘These results showed that the combination of EPA and DHA could effectively treat the depression in women’.
Dr. Holub's Comments:
The present review of previous relevant trials on this topic indicate a beneficial effect of EPA plus DHA supplementation on depressed mood in women of varying age groups. However, the overall findings support a somewhat stronger anti-depressant effect in younger as compared to elderly women. The average daily intake of EPA plus DHA in the eight clinical trials as reviewed was approx. 3 grams ( 2.83 grams or 2830 mgms daily). Even though the human brain contains very high levels of DHA along with very low levels of EPA, it is of interest to note that 7 of the 8 studies used omega-3 supplements having more EPA than DHA. EPA may serve to improve blood flow to the brain via its beneficial vascular effects thereby offering effects independent of its accumulation in brain tissue per se. It is also possible that the bio-active products derived from EPA/DHA known as resolvins and protectins may offer neuronal benefits related to depressive symptomology.