Physical activity is associated with better cognitive performance including enhanced executive function and memory. Although physical activity has many beneficial effects on physical health, the link to cognitive performance may be related to body fat composition, according to a recent study led by Dr. Aaron Barbey from UIUC Psychology and Beckman research scientist Ryan Larson.
Brain health can be quantified by the amount of a chemical called N-acetyl aspartic acid (NAA) present compared to a reference mark. NAA can be detected using magnetic resonance spectroscopy, a type of noninvasive brain imaging. When present in white matter (the long fiberous tracks that allow distant brain regions to communicate with each other) it is thought to be a marker of the brain's structural integrity. Previous work had found that NAA concentration were reduced in individuals with poor cardiovascular health and in those with higher body fat. However those with higher body fat also tend to have poorer cardiorespiratory health, making it difficult to determine which has a stronger association with brain health.
In the new research, recently published in the journal of Metabolic Brain Disease, a multi-institution team sought to disentangle the association between these two markers of physical health. They found that in young adults, body fat was indeed correlated with NAA in white matter and that this association was able to account for much of the correlation with cardiorespiratory fitness. The results suggest that association of fitness and brain may be more closely tied to body composition. Such findings may help inform the creation of future interventions designed to preserve or enhance brain health and cognitive performance across the lifespan.
You can read more about this work on the Beckman Institute New Release.