Association of Dietary α-Carotene and β-Carotene Intake with Low Cognitive Performance in Older Adults: A Cross-Sectional Study from the National Health and Nutrition Examination Survey

This study aims to examine the relationships of dietary alpha-carotene and beta-carotene intake with cognitive function. The data were selected from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. A total of 2009 participants were included in this analysis. Dietary alpha-carotene and beta-carotene intake were averaged by two 24-h dietary recalls. The Consortium to Establish a Registry for Alzheimer's Disease Word Learning subset (CERAD W-L), Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST) were used to evaluate cognitive function. Logistic regression and restricted cubic spline models were applied to explore the associations of dietary alpha-carotene and beta-carotene intake with cognitive performance. After adjusting for all confounding factors, compared with individuals in the lowest quartile of beta-carotene dietary intake, those in the highest quartile had lower risks of both CERAD W-L decline [odds ratio (OR) = 0.63, 95% confidence interval (CI): 0.44-0.90] and AFT decline (OR = 0.66, 95% CI: 0.47-0.94). In addition, the third quartile of beta-carotene dietary intake had a significantly decreased risk of lower DSST (OR = 0.67, 95% CI: 0.48-0.83). Compared with the lowest quartile of alpha-carotene intake, the OR of AFT decline in the highest intake quartile was 0.66 (95% CI: 0.46, 0.94). For males, both dietary alpha-carotene and beta-carotene intake were associated with a decreased risk of AFT decline (OR = 0.42, 95% CI: 0.25-0.71; OR = 0.51, 95% CI: 0.30-0.85, respectively). For females, dietary alpha-carotene intake was associated with a decreased risk of CERAD W-L decline (OR = 0.55, 95% CI: 0.33-0.91) and dietary beta-carotene intake was associated with decreased risks of both CERAD W-L and AFT decline (OR = 0.37, 95% CI: 0.21-0.64; OR = 0.58, 95% CI: 0.37-0.91, respectively). Our results suggested that higher dietary alpha-carotene and beta-carotene intake had inverse effects on cognitive function decline among older adults.