薬理と治療

Abstract

Objectives We aimed to examine the effects of daily dietary docosahexaenoic acid（DHA）and eicosapentaenoic acid（EPA）supplementation on cognitive functions in this 2-year randomized, double-blind, placebo-controlled trial. Methods Healthy elderly Japanese aged 57 years or over（n＝111, 72.4±7.7 years）were randomized to active and placebo groups. The active group consumed fish sausages containing 1720 mg DHA and 407 mg EPA daily for 24 months；the placebo group consumed fish sausages containing olive oil daily for the first 12 months and fish sausages containing DHA and EPA daily for the next 12 months. Results The plasma and erythrocyte plasma membrane DHA and EPA levels significantly increased in the active group at 6 and 12 months. Further, the mean changes in some of cognitive function test scores from the baseline to month 6 and month 12 were significantly higher in the active group. The mean changes in cognitive function test scores from the baseline to month 12 were positively correlated with plasma membrane DHA level and EPA levels, and negatively correlated with n-6／n-3 polyunsaturated fatty acid ratio. Conclusion Long-term daily dietary DHA and EPA supplementation seems to have beneficial effects against age-related cognitive decline in healthy elderly Japanese with very mild dementia.