title: Low macular pigment optical density is associated with lower cognitive performance in a large, population-based sample of older adults.
abstract: Macular pigment (MP) is comprised of the carotenoids lutein (L), zeaxanthin (Z), and meso-zeaxanthin (MZ), which selectively accumulate at the macula (central retina) of the eye and are neuroprotective. These carotenoids are also present in the brain, and evidence suggests a close correlation between retinal and brain concentrations. We investigated the relationship between MP and cognitive function in 4453 adults aged ≥ 50 years as part of The Irish Longitudinal Study on Aging. Macular pigment optical density (MPOD) was determined using customized heterochromatic flicker photometry-a quick and noninvasive way of measuring the concentration of the pigment. Lower MPOD was associated with poorer performance on the mini-mental state examination (p = 0.026) and on the Montreal cognitive assessment (p = 0.016). Individuals with lower MPOD also had poorer prospective memory (p = 0.011), took longer time to complete a trail-making task (p = 0.003), and had slower and more variable reaction times on a choice reaction time task (p = 0.000 and 0.001). These associations were only slightly attenuated following adjustment for physical and mental health. There was no significant association between MPOD and verbal fluency, word recall, visual reasoning, or picture memory. Overall, the findings support the theory that xanthophyll carotenoids impact on cognitive function, underscoring the need for exploration of novel, noninvasive biomarkers for cognitive vulnerability and preventive strategies.
authors.affiliation: Department of Medical Gerontology, Trinity College, Dublin, Ireland. feeneyjo@tcd.ie
authors.forename: Joanne
authors.initials: J
authors.lastname: Feeney
authors.forename: Ciarán
authors.initials: C
authors.lastname: Finucane
authors.forename: George M
authors.initials: GM
authors.lastname: Savva
authors.forename: Hilary
authors.initials: H
authors.lastname: Cronin
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
authors.forename: John M
authors.initials: JM
authors.lastname: Nolan
authors.forename: Rose Anne
authors.initials: RA
authors.lastname: Kenny
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D003072:Cognition Disorders / Q000150:complications*; D018672:Community Health Planning; D003936:Diagnosis, Computer-Assisted; D056344:Executive Function; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000150:complications*; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D012044:Regression Analysis
keywords: Aging; Cognitive impairment; Macular pigment optical density