Plasma Lutein and Zeaxanthin Are Associated With Better Cognitive Function Across Multiple Domains in a Large Population-Based Sample of Older Adults: Findings from The Irish Longitudinal Study on Aging.
BACKGROUND
Low blood serum or plasma concentrations of the xanthophyll carotenoids lutein and zeaxanthin have been implicated in poorer cognitive health in older adults. However, equivocal results from smaller studies and clinical trials highlight the need for large population-based studies with comprehensive measures of cognitive function and adjustment for multiple confounders to examine such associations in more depth.


METHODS
In the current study, we investigated the association between plasma lutein and zeaxanthin and domain-specific cognitive performance in 4,076 community-dwelling adults aged 50 years or older from The Irish Longitudinal Study on Ageing. Mixed-effects models were fitted with adjustment for demographic and socioeconomic factors, health conditions, and health behaviors.


RESULTS
Higher plasma lutein and zeaxanthin were independently associated with better composite scores across the domains of global cognition, memory, and executive function. We also found evidence that higher plasma zeaxanthin, but not lutein, was associated with better processing speed. These associations were consistent across domains.


CONCLUSIONS
Further investigation of the prognostic value of carotenoid concentrations, and their changes, on cognition in similar population-based samples longitudinally is warranted.
Centre for Public Health, Queens University Belfast, Royal Victoria Hospital, UK.|The Irish Longitudinal Study on Ageing, Lincoln Gate, Trinity College, Dublin, Ireland.
Joanne
J
Feeney
The Irish Longitudinal Study on Ageing, Lincoln Gate, Trinity College, Dublin, Ireland.
Neil
N
O'Leary
Nutrition Research Centre Ireland, Macular Pigment Research Group, School of Health Science, Waterford Institute of Technology, Ireland.
Rachel
R
Moran
The Irish Longitudinal Study on Ageing, Lincoln Gate, Trinity College, Dublin, Ireland.
Aisling M
AM
O'Halloran
Nutrition Research Centre Ireland, Macular Pigment Research Group, School of Health Science, Waterford Institute of Technology, Ireland.
John M
JM
Nolan
Nutrition Research Centre Ireland, Macular Pigment Research Group, School of Health Science, Waterford Institute of Technology, Ireland.
Stephen
S
Beatty
Centre for Public Health, Queens University Belfast, Royal Victoria Hospital, UK.
Ian S
IS
Young
The Irish Longitudinal Study on Ageing, Lincoln Gate, Trinity College, Dublin, Ireland.
Rose Anne
RA
Kenny
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003071:Cognition; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007494:Ireland; D008137:Longitudinal Studies; D014975:Lutein / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D065146:Zeaxanthins / Q000097:blood*
D015415:Biomarkers; D065146:Zeaxanthins; D014975:Lutein
Antioxidant; Brain aging; Nutrition