Education mitigates age‐related decline in N‐Acetylaspartate levels
Kirk I. Erickson1 
Regina L. Leckie1 
Andrea M. Weinstein1 
Polina Radchenkova6 
Bradley P. Sutton4 
Ruchika Shaurya Prakash2 
Michelle W. Voss3 
Laura Chaddock-Heyman5 
Edward McAuley5 
[1] Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania;Department of Psychology, Ohio State University, Columbus, Ohio;Department of Psychology, University of Iowa, Iowa City, Iowa;Department of Bioengineering, University of Illinois, Urbana, Illinois;Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana, Illinois;Center for Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania
Greater educational attainment is associated with better neurocognitive health in older adults and is thought to reflect a measure of cognitive reserve. In vivo neuroimaging tools have begun to identify the brain systems and networks potentially responsible for reserve.
Methods
We examined the relationship between education, a commonly used proxy for cognitive reserve, and N-acetylaspartate (NAA) in neurologically healthy older adults (N = 135; mean age = 66 years). Using single voxel MR spectroscopy, we predicted that higher levels of education would moderate an age-related decline in NAA in the frontal cortex.
Results
After controlling for the variance associated with cardiorespiratory fitness, sex, annual income, and creatine levels, there were no significant main effects of education (B = 0.016, P = 0.787) or age (B = −0.058, P = 0.204) on NAA levels. However, consistent with our predictions, there was a significant education X age interaction such that more years of education offset an age-related decline in NAA (B = 0.025, P = 0.031). When examining working memory via the backwards digit span task, longer span length was associated with greater education (P < 0.01) and showed a trend with greater NAA concentrations (P < 0.06); however, there was no age X education interaction on digit span performance nor a significant moderated mediation effect between age, education, and NAA on digit span performance.
Conclusions
Taken together, these results suggest that higher levels of education may attenuate an age-related reduction in neuronal viability in the frontal cortex.