Long-chain omega-3 fatty acids improve brain function and structure in older adults.

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.

Diagnostic transcranial ultrasound perfusion-imaging at 2.5 MHz does not affect the blood-brain barrier.

The purpose was to assess whether standard ultrasound (US) perfusion-imaging by means of contrast-enhanced transcranial color-coded sonography (TCCS) affects the blood-brain barrier (BBB) in patients with small-vessel disease (SVD). One week after a screening MRI to exclude a preexisting BBB disruption, unilateral TCCS phase inversion harmonic imaging (PIHI) was performed in an axial diencephalic plane after intravenous bolus application of 2.5 mL SonoVue (IGEA, Bracco, Italy). Magnetic resonance imaging (MRI) was performed immediately after US. In five patients, PIHI was performed applying a mean mechanical index (MI) of 0.7 +/- 0.1 for a time period of 2.5 min. MRI was started 12 +/- 2 min after US contrast injection. Comparisons of initial and post-US MRI by four blinded readers did not show any signs of BBB disruption. It is concluded that standard contrast-enhanced US perfusion imaging in patients with SVD did not lead to MRI-detectable BBB changes. This gives further evidence for safety of diagnostic US. Future investigations with larger sample sizes and higher-field MRI might give further insights into potential bioeffects of diagnostic, as well as therapeutic, contrast-enhanced transcranial US.