DHA-rich oil modulates the cerebral haemodynamic response to cognitive tasks in healthy young adults: a near IR spectroscopy pilot study

Abstract:

The impact of dietary n-3 PUFA on behavioural outcomes has been widely researched; however, very little attention has been given to their impact on brain functioning in physiological terms.

A total of twenty-two healthy adults took part in this double-blind, placebo-controlled study, wherein the cerebral haemodynamic effects of 12 weeks of daily dietary supplementation with either 1 g DHA-rich or 1 g EPA-rich fish oil (FO) or placebo (1 g olive oil) were assessed. Relative changes in the concentration of oxygenated Hb (oxy-Hb) and deoxygenated Hb were assessed in the prefrontal cortex using near IR spectroscopy (NIRS) during the performance of four computerised cognitive tasks.

Supplementation with DHA-rich FO, in comparison with placebo, resulted in a significant increase in the concentrations of oxy-Hb and total levels of Hb, indicative of increased cerebral blood flow (CBF), during the cognitive tasks. In comparison, no effect on CBF was observed following supplementation with EPA-rich FO, where concentration changes in the chromophores followed the same pattern as placebo. These encouraging pilot data warrant further application of NIRS in this area.

In this pilot study involving 22 young, healthy adults, blood flow to the pre-frontal region of the brain was assessed using a novel technique (near infra-red specroscopy or NIRS) while they performed computer tasks designed to assess cognitive performance.  

These cerebral blood flow measures were taken both before and after 12 weeks of dietary supplementation with 1g/day of either DHA-rich fish oil, EPA-rich fish oil or placebo.

Compared with their pre-treatment baseline measures, the DHA-supplemented group showed significant increases in cerebral blood flow at the 12 week follow-up, while no changes were observed for participants receiving the high-EPA fish oil or the placebo.