title: Cognitive Function and Its Relationship with Macular Pigment Optical Density and Serum Concentrations of its Constituent Carotenoids.
abstract: BACKGROUND
  Macular pigment (MP) levels correlate with brain concentrations of lutein (L) and zeaxanthin (Z), and have also been shown to correlate with cognitive performance in the young and elderly.
  
  
  OBJECTIVE
  To investigate the relationship between MP, serum concentrations of L and Z, and cognitive function in subjects free of retinal disease with low MP (Group 1, n = 105) and in subjects with AMD (Group 2, n = 121).
  
  
  METHODS
  MP was measured using customized heterochromatic flicker photometry and dual-wavelength autofluorescence; cognitive function was assessed using a battery of validated cognition tests; serum L and Z concentrations were determined by HPLC.
  
  
  RESULTS
  Significant correlations were evident between MP and various measures of cognitive function in both groups (r = -0.273 to 0.261, p≤0.05, for all). Both serum L and Z concentrations correlated significantly (r = 0.187, p≤0.05 and r = 0.197, p≤0.05, respectively) with semantic (animal) fluency cognitive scores in Group 2 (the AMD study group), while serum L concentrations also correlated significantly with Verbal Recognition Memory learning slope scores in the AMD study group (r = 0.200, p = 0.031). Most of the correlations with MP, but not serum L or Z, remained significant after controlling for age, gender, diet, and education level.
  
  
  CONCLUSIONS
  MP offers potential as a non-invasive clinical biomarker of cognitive health, and appears more successful in this role than serum concentrations of L or Z.
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Kelly
authors.affiliation: Memory Clinic, Mercers Institute for Research on Ageing, St. James's Hospital, Dublin, Ireland.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Coen
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Kwadwo Owusu
authors.initials: KO
authors.lastname: Akuffo
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.|Institute of Vision Research, Whitfield Clinic, Waterford, Ireland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Jessica
authors.initials: J
authors.lastname: Dennison
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Rachel
authors.initials: R
authors.lastname: Moran
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Jim
authors.initials: J
authors.lastname: Stack
authors.affiliation: Howard Foundation, Cambridge, UK.
authors.forename: Alan N
authors.initials: AN
authors.lastname: Howard
authors.affiliation: University Hospital Waterford, Age-Related Care Unit, Waterford, Ireland.
authors.forename: Riona
authors.initials: R
authors.lastname: Mulcahy
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: John M
authors.initials: JM
authors.lastname: Nolan
mesh_terms: D000328:Adult; D000368:Aged; D002338:Carotenoids / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D003072:Cognition Disorders / Q000097:blood* / Q000209:etiology*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D014975:Lutein / Q000097:blood; D008268:Macular Degeneration / Q000097:blood* / Q000150:complications* / Q000628:therapy; D065348:Macular Pigment / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010783:Photometry; D041623:Tomography, Optical Coherence; D065146:Zeaxanthins / Q000097:blood
chemical_list: D065348:Macular Pigment; D065146:Zeaxanthins; D002338:Carotenoids; D014975:Lutein
keywords: Age-related macular degeneration; biomarker; cognitive function; lutein; macular pigment; zeaxanthin