Long-Chain Omega-3 Fatty Acids Improve Brain Function and Structure in Older Adults

TLDR

Long‑chain omega‑3 fatty acids from fish or oil are thought to benefit the aging brain. The study aimed to determine whether supplementing LC‑n3‑FA improves cognition in older adults and to explore underlying mechanisms. Sixty‑five healthy adults aged 50–75 were randomized to 26 weeks of fish oil (2.2 g/day LC‑n3‑FA) or placebo, with pre‑ and post‑intervention assessments of cognition, brain imaging, vascular and blood markers. LC‑n3‑FA supplementation significantly improved executive function, enhanced white‑matter integrity and gray‑matter volume in key brain regions, reduced carotid intima‑media thickness and diastolic blood pressure, and these benefits correlated with higher omega‑3‑index, increased BDNF, and lower fasting insulin, providing first‑time evidence of cognitive and structural brain benefits in healthy older adults.

Abstract

Higher intake of seafish or oil rich in long-chain omega-3 polyunsaturated fatty acids (LC-n3-FA) may be beneficial for the aging brain. We tested in a prospective interventional design whether high levels of supplementary LC-n3-FA would improve cognition, and addressed potential mechanisms underlying the effects. Sixty-five healthy subjects (50–75 years, 30 females) successfully completed 26 weeks of either fish oil (2.2 g/day LC-n3-FA) or placebo intake. Before and after the intervention period, cognitive performance, structural neuroimaging, vascular markers, and blood parameters were assayed. We found a significant increase in executive functions after LC-n3-FA compared with placebo (P = 0.023). In parallel, LC-n3-FA exerted beneficial effects on white matter microstructural integrity and gray matter volume in frontal, temporal, parietal, and limbic areas primarily of the left hemisphere, and on carotid intima media thickness and diastolic blood pressure. Improvements in executive functions correlated positively with changes in omega-3-index and peripheral brain-derived neurotrophic factor, and negatively with changes in peripheral fasting insulin. This double-blind randomized interventional study provides first-time evidence that LC-n3-FA exert positive effects on brain functions in healthy older adults, and elucidates underlying mechanisms. Our findings suggest novel strategies to maintain cognitive functions into old age.