Increased Carbohydrate Intake is Associated with Poorer Performance in Verbal Memory and Attention in an APOE Genotype-Dependent Manner

Evidence suggests that a diet low in carbohydrates can impact on cognitive performance among those with Alzheimer's disease (AD). However, there is a lack of data assessing this relationship among cognitively normal (CN) older adults at increased future risk of developing AD due to carriage of the apolipoprotein E (APOE) epsilon 4 allele. We assessed the cross-sectional association between carbohydrate intake, cognitive performance, and cerebral amyloid-beta (A beta) load in CN older adults, genotyped for APOE epsilon 4 allele carrier status. Greater carbohydrate intake was associated with poorer performance in verbal memory in APOE epsilon 4 allele non-carriers, and poorer performance in attention in APOE epsilon 4 allele carriers. There were no associations between carbohydrate intake and cerebral A beta load. These results provide support to the idea that decreasing carbohydrate intake may offer neurocognitive benefits, with specific cognitive domains affected in an APOE genotype-dependent manner. These findings warrant further investigation utilizing a longitudinal study design.