Association of low-carbohydrate-diet score and cognitive performance in older adults: National Health and Nutrition Examination Survey (NHANES)

Background: To investigate the association between low-carbohydrate-diet (LCD) score and cognitive performance based on a nationally representative sample aged & GE; 60 years from National Health and Nutrition Examination Survey (NHANES) database. Methods: This cross-sectional study included 2,537 eligible older adults from the NHANES database 2011-2014. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word learning subtest, Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST) were used to assess the cognitive performance. All participants were categorized into the low and normal cognitive performance groups. The univariate and multivariate logistic regression analyses were utilized to evaluate the association of LCD score with cognitive performance. Stratified analyses based on age, body mass index (BMI), gender, marital status, education level was conducted. Results: After adjusting age, education level, marital status, household income, history of diabetes, history of hypertension, history of congestive heart failure, history of coronary heart disease, history of heart disease, history of stroke, magnesium and the using of psychotropic medication, LCD score was correlated with the CERAD word learning subtest. The associations between LCD score and AFT, DSST were not statistically significant. Moreover, LCD score was also related to cognitive performance among individuals who were aged < 65 years or BMI 25-30 kg/m(2) or was married/separated, or had an education level of high school or above. Conclusion: The adherences to LCD might be associated with the risk of cognitive performance among older adults. Further large-scale cohort studies are needed to test the causal relationship of LCD and cognitive performance.