Dietary carotenoids and cognitive function among US adults, NHANES 2011–2014

Objectives: Dietary carotenoids may limit neuronal damage from free radicals, potentially serving as a modifiable risk factor for cognitive decline. We examined intake of lutein and zeaxanthin (L and Z) in relation to cognitive performance among 2011-2014 National Health and Nutrition Examination Survey participants aged ≥60 years. Methods: L and Z intake from foods and supplements was estimated from two non-consecutive 24-hour diet recalls. Outcomes included the CERAD Word Learning sub-test score, Animal Fluency test score, and Digit Symbol Substitution test score. Regression models were adjusted for survey design variables, year, sex, age, race/ethnicity, body mass index, family income, education, alcohol, and smoking. Results: Among the 2796 participants, higher dietary intake of L and Z was associated with higher score on each test. For example, the highest quartile of L and Z intake was associated with a 2.52 point increase (SE=0.86 points, P=0.01) on the digit symbol score test, compared with the lowest quartile. There were differences by race/ethnicity, with positive associations generally stronger for Black compared to white participants. Discussion: Further research from longitudinal studies is needed, but increasing L and Z intake may help to prevent or slow cognitive decline.