Dietary Xanthophyll and Choline Intake Interactively Influence Cognitive Flexibility in Middle-Adulthood

Abstract

Abstract Objectives Consumption and biomarker status of the xanthophyll-carotenoids lutein + zeaxanthin and the dietary component choline have been linked to benefits in cognition. However, knowledge on the interactive influence of these dietary components on cognition is sparse. We examined associations between dietary and bio-markers of lutein + zeaxanthin, choline, and cognitive flexibility among adults with overweight and obesity. Methods 80 adults with overweight and obesity completed 7-day diet records, venous blood draws, heterochromatic flicker photometry for assessment of macular pigmentation (MPOD), the Kaufman Brief Intelligence Test–2 (IQ), and a Switch task of cognitive flexibility while undergoing electroencephalographic recording (ERP). Multiplicative interaction terms were calculated to assess interactive capabilities. Hierarchical linear regressions controlling for age, body mass index, sex, annual household income, and IQ were utilized to assess independent and interactive contributions of dietary and metabolite data on Switch task outcomes. Results Dietary intake of lutein + zeaxanthin and choline were correlated with serum lutein concentrations (r = 0.42, P < 0.01, r = 0.35, P < 0.01) but not with plasma choline metabolites nor MPOD. Higher intakes of lutein + zeaxanthin and choline were associated interactively, but not independently, with faster reaction time (RT; β = −0.29, P = 0.01). Plasma phosphatidylcholine (PC) concentrations were associated with accuracy in Switch trials (β = 0.28, P = 0.01), while no other biomarkers were associated with cognitive outcomes. Dietary intake and biomarker data were not related to the N2 nor P3 ERP components. Conclusions Individuals with greater intake of lutein + zeaxanthin and choline exhibited faster RT during a cognitive flexibility task. Circulating PC was associated with higher response accuracy. These benefits were evident without differences in the N2 or P3 components, suggesting alternative neural benefits of xanthophyll and choline consumption on cognitive function. Funding Sources Funds were provided by the Hass Avocado Board, the Department of Kinesiology and Community Health at the University of Illinois, and the USDA National Institute of Food and Agriculture, Hatch project 1,009,249.