title: The impact of supplemental macular carotenoids in Alzheimer's disease: a randomized clinical trial.
abstract: BACKGROUND
  Patients with Alzheimer's disease (AD) exhibit significantly less macular pigment (MP) and poorer vision when compared to control subjects.
  
  
  OBJECTIVE
  To investigate supplementation with the macular carotenoids on MP, vision, and cognitive function in patients with AD versus controls.
  
  
  METHODS
  A randomized, double-blind clinical trial with placebo and active arms. 31 AD patients and 31 age-similar control subjects were supplemented for six months with either Macushield (10 mg meso-zeaxanthin [MZ]; 10 mg lutein [L]; 2 mg zeaxanthin [Z]) or placebo (sunflower oil). MP was measured using dual-wavelength autofluorescence (Heidelberg Spectralis®). Serum L, Z, and MZ were quantified by high performance liquid chromatography. Visual function was assessed by best corrected visual acuity and contrast sensitivity (CS). Cognitive function was assessed using a battery of cognition tests, including the Cambridge Neuropsychological Test Automated Battery (CANTAB)).
  
  
  RESULTS
  Subjects on the active supplement (for both AD and non-AD controls) exhibited statistically significant improvement in serum concentrations of L, Z, MZ, and MP (p < 0.001, for all) and also CS at (p = 0.039). Also, for subjects on the active supplement, paired samples t-tests exhibited four significant results (from five spatial frequencies tested) in the AD group, and two for the non-AD group, and all indicating improvements in CS. We found no significant changes in any of the cognitive function outcome variables measured (p > 0.05, for all).
  
  
  CONCLUSIONS
  Supplementation with the macular carotenoids (MZ, Z, and L) benefits patients with AD, in terms of clinically meaningful improvements in visual function and in terms of MP augmentation.
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
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Loskutova
authors.affiliation: Howard Foundation, Cambridge, UK Downing College, University of Cambridge, Cambridge, UK.
authors.forename: Alan
authors.initials: A
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: 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: University Hospital Waterford, Age-Related Care Unit, Waterford, Ireland.
authors.forename: Maggie
authors.initials: M
authors.lastname: Bolger
authors.affiliation: Mercer's Institute for Successful 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: 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: 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.
authors.forename: Niamh
authors.initials: N
authors.lastname: Owens
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Power
authors.affiliation: Northern Ireland, Centre for Food and Health (NICHE), University of Ulster, Coleraine, UK.
authors.forename: David
authors.initials: D
authors.lastname: Thurnham
authors.affiliation: Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000178:diet therapy*; D000975:Antioxidants / Q000627:therapeutic use*; D002338:Carotenoids / Q000097:blood / Q000627:therapeutic use*; D002851:Chromatography, High Pressure Liquid; D003072:Cognition Disorders / Q000178:diet therapy* / Q000209:etiology; D015350:Contrast Sensitivity / Q000187:drug effects; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D014975:Lutein; D065348:Macular Pigment / Q000378:metabolism; D008297:Male; D008609:Mental Status Schedule; D009483:Neuropsychological Tests; D014792:Visual Acuity / Q000187:drug effects; D065146:Zeaxanthins
chemical_list: D000975:Antioxidants; D065348:Macular Pigment; D065146:Zeaxanthins; D002338:Carotenoids; D014975:Lutein
keywords: Age-related macular degeneration; Alzheimer's disease; cognitive function; contrast sensitivity; lutein; meso-zeaxanthin; randomized clinical trial; visual function; zeaxanthin