Comparison between the AA/EPA ratio in depressed and non depressed elderly females: omega-3 fatty acid supplementation correlates with improved symptoms but does not change immunological parameters

Single-centre, randomized, double-blind, placebo-controlled, parallel-group trial in depressed elderly women (66-95 years). DSM-IV diagnosed depression; MMSE >24. 46 participants: 22 in the omega-3 group and 24 in placebo.

One tablespoon of omega-3 PUFA oil daily (2.5 g/day; EPA:DHA ratio 2:1), taken orally before lunch, for 8 weeks.

Omega-3 supplementation significantly improved depressive symptoms after 8 weeks (GDS 17.1±3.7 at baseline to 11.6±4.3). It also lowered whole-blood and RBC membrane AA/EPA ratios, indicating improved omega-3 status. Correlations between changes in GDS and AA/EPA ratio were observed with CD2, CD19, CD4, CD16, and CD4/CD8, but immunological functions overall did not improve significantly. AA/DHA ratio did not change significantly. Whole-blood AA/EPA ratio can monitor omega-3 status. This regimen may alleviate depressive symptoms in elderly depressed individuals; immune effects remain unclear.

Small, single-centre 8-week trial in elderly depressed women; limited generalizability; immunological outcomes were inconclusive; correlations between omega-3 changes and immune parameters were modest.