Whole egg consumption and cognitive function among US older adults.

ABSTRACT

BACKGROUND: Eggs are an affordable food providing many shortfall nutrients with the potential to improve cognitive health. We assessed the relationship between whole egg consumption and cognitive functioning among a US nationally representative sample of older adults. METHODS: Individual-level data (2816 adults, aged ≥ 60 years) were obtained from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 waves. Cognitive assessments included the Consortium to Establish a Registry for Alzheimer's Disease Word List Learning Test (CERAD-WL), Word List Recall Test (CERAD-DR), Animal Fluency Test (AF) and Digit Symbol Substitution Test (DSST). A composite cognitive z-score was constructed based on the individual tests to represent one's overall cognitive functioning. Multiple linear and logistic regressions were performed to examine the effect of whole egg consumption on cognitive functioning, adjusting for individual characteristics and survey design. RESULTS: Approximately 57% of older adults consumed whole eggs, with an average daily intake of 34 g of whole egg equivalent among consumers. The average z-scores of the CERAD-WL, CERAD-DR, AF and DSST tests were -0.08, 0.23, 0.37 and 0.42, respectively, and the overall composite cognitive z-score was 0.24 among older adults. Regression analyses found that neither whole egg consumption status, nor daily intake quantity was associated with cognitive test scores. CONCLUSIONS: No association was found between whole egg consumption and cognitive functioning among US older adults. Study limitations included cross-sectional study design and measurement errors. Future studies with longitudinal or experimental design are warranted to examine the possible link between egg consumption and cognition in older adults.