title: Macular response to supplementation with differing xanthophyll formulations in subjects with and without age-related macular degeneration.
abstract: OBJECTIVE
  Our aim was to investigate the macular response to three different supplements containing lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ) in normal subjects and those with age-related macular degeneration (AMD).
  
  
  METHODS
  Macular pigment optical density (MPOD) and serum xanthophyll concentrations were measured in normal (n = 31) and AMD subjects (n = 32), randomly assigned to: group 1 (20 mg L, 2 mg Z, 0.3 mg MZ), group 2 (10 mg L, 2 mg Z, 10 mg MZ) or group 3 (3 mg L, 2 mg Z, 17 mg MZ). MPOD was measured at baseline, 2, 4, 6 and 8 weeks and at 0.25°, 0.5°, 1.0° and 1.75° of eccentricity using customised heterochromatic flicker photometry and serum xanthophylls by HPLC.
  
  
  RESULTS
  MPOD increased significantly at all eccentricities in each group (p < 0.05), except at 1.75° in group 3 (p = 0.242). There was no difference in MPOD measurements between AMD and normal subjects, except for group 2, where AMD subjects exhibited a greater response at 1.75° (p = 0.012). Final serum concentrations of MZ were positively and significantly related to final MPOD values at each eccentricity in all subjects. Targeted analysis of those subjects receiving the MZ-containing supplements exhibited stronger relationships between serum MZ concentrations and MPOD at 0.25° in group 3 than group 2; in group 2 all associations were positive, but only significant at 1.75°.
  
  
  CONCLUSIONS
  Serum concentrations of MZ were strongly correlated with MPOD after 8 weeks of supplementation with the group 3 formulation, but the inclusion of L in the group 2 formulation may result in greater MPOD augmentation across the spatial profile.
authors.affiliation: Northern Ireland Centre for Food and Health (NICHE), University of Ulster, Coleraine, UK, di.thurnham@ulster.ac.uk.
authors.forename: David I
authors.initials: DI
authors.lastname: Thurnham
authors.forename: John M
authors.initials: JM
authors.lastname: Nolan
authors.forename: Alan N
authors.initials: AN
authors.lastname: Howard
authors.forename: Stephen
authors.initials: S
authors.lastname: Beatty
mesh_terms: D000368:Aged; D002851:Chromatography, High Pressure Liquid; D003720:Densitometry; D004032:Diet; D004311:Double-Blind Method; D004339:Drug Compounding; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D014975:Lutein / Q000008:administration & dosage* / Q000097:blood; D008268:Macular Degeneration / Q000097:blood / Q000188:drug therapy*; D065348:Macular Pigment / Q000097:blood*; D008297:Male; D008875:Middle Aged; D024341:Xanthophylls / Q000097:blood; D065146:Zeaxanthins / Q000008:administration & dosage* / Q000097:blood
chemical_list: D065348:Macular Pigment; D024341:Xanthophylls; D065146:Zeaxanthins; C584722:meso-zeaxanthin; D014975:Lutein