Fatty acids and executive functions: Behavioral performance and cortical activation across the lifespan

An imbalance in the omega-6 to omega-3 fatty acid ratio may be a preventable contributor to cognitive deficits across the lifespan. Omega-6 and omega-3 fatty acids are integral to neuronal growth and communication in the hippocampus and frontal cortex, brain areas that subserve executive functions (EF). EF are higher order cognitive functions that control thoughts, behaviors, and emotions. The present study focused on how the balance of omega-6 and omega-3 fatty acids contributes to EF in children 7 to 12 years old and older adults 65 to 79 years old. One hundred fifty-two children were screened for their omega-6 and omega-3 fatty acid intake using three 24-hour diet recalls, and 78 children representing equal recruitment of nine fatty acid intake patterns completed standardized measures of memory, working memory, and planning and one novel planning task, the Electric Maze Task (EMT). Near-infrared spectroscopy (NIRS) data were also collected. Eighty-eight older adults recruited for a study of cognitive decline also completed standardized measures of memory, working memory, and visual processing.;The omega-6 to omega-3 ratio predicted performance on EF tasks among the children and older adults. The younger children (7- to 9-year-olds) and oldest adults (75- to 79-year-olds) benefitted from balanced ratios (e.g., low omega-3 and low omega-6). The older children (10- to 12-year-olds) and youngest adults (65- to 69-year-olds) benefitted from imbalanced ratios (e.g., high omega-3 and low omega-6). The ratio also predicted brain activity in the right and central prefrontal cortex associated with better performance on the EMT and planning problems. The balance of fatty acids likely supports the flexible use of prefrontal cortical resources necessary for complex EF. Different balances of omega-6 and omega-3 fatty acids are optimal at different points in development, and additional work with the omega-6 to omega-3 ratio will help elucidate the optimal diet for cognitive function across the lifespan.