Long-chain Polyunsaturated Fatty Acid Supplementation Improves Mood in Elderly Japanese Men

Although several studies have reported the effects of long-chain polyunsaturated fatty acid (LCPUFA) supplementation on the mood in healthy adults, the effects of LCPUFA on elderly individuals remain unclear. Thus, we hypothesized that LCPUFA supplementation improves mood in the elderly. To address this hypothesis, 115 elderly Japanese men aged 55-64 years were assigned and randomly allocated to the LCPUFA or placebo group. Participants received 4 weeks of supplementation with LCPUFA-containing oil (docosahexaenoic acid (DHA) 300 mg/day, eicosapentaenoic acid (EPA) 100 mg/day, arachidonic acid (ARA) 120 mg/day) or a placebo oil. Mood was assessed using the Profile of Mood States (POMS) before and after supplementation as the secondary outcome in a previously performed randomized controlled trial on cognitive function. A total of 113 participants completed the supplementation period. One hundred participants (LCPUFA, n = 51; placebo, n = 49) who were eligible for evaluation of mood were analyzed. Increases in vigor scores on POMS, reflecting a positive mood, were significantly larger in the LCPUFA group than in the placebo group (LCPUFA, +1.8; placebo, -0.5). No significant differences were observed in changes in other negative mood scores between groups. DHA and ARA content in plasma phospholipids were increased by 0.8% and 0.7%, respectively, in the LCPUFA group, and were significantly larger than those in the placebo group. Dietary DHA, EPA, and ARA intake was unchanged during the study. These results suggest that LCPUFA supplementation may improve vigor (positive mood) in elderly Japanese men.