Effects of Food Supplementation with Fish Oil on Cognitive Function in Middle-Aged and Older Adults —A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

Abstract

Background : To delay the onset of dementia with age, healthy adults must take preventive measures before cognitive decline occurs. Cognitive decline leads to a decrease in the quality of life (QOL). Fish oil also improves cognitive functions. Therefore, we examined the effects of fish oil intake on the cognitive function and QOL of middle-aged and older adults. Methods : A randomized, double-blind, placebo-controlled, parallel-group study was conducted to evaluate the effects of fish oil on cognitive function and QOL in middle-aged and older participants. One hundred and ten participants were enrolled and randomly divided into active and placebo food groups. Participants consumed either food containing fish oil or food without fish oil for 12 weeks. As the main outcome, cognitive function was assessed before and after ingestion using the Wechsler Memory Scale-Revised and the Stroop test. The secondary outcome, QOL, was also examined using SF-36. Results : The active food group showed statistical significance in the “Logical Memory I” and “Stroop interference rate” compared to the placebo food group (P < 0.05). Furthermore, the active food group showed statistically significant differences in “Mental Component Summary” compared to the placebo food group (P < 0.05). No adverse events attributable to the study food were observed during the study period. Conclusions : Overall, fish oil improved cognitive function in middle-aged and older adults.