title: A double-blind, placebo-controlled study on the effects of lutein and zeaxanthin on photostress recovery, glare disability, and chromatic contrast.
abstract: OBJECTIVE
  Past studies have shown that higher macular pigment optical density (MPOD) and lutein (L) and zeaxanthin (Z) supplementation are related to improvements in glare disability, photostress recovery, and chromatic contrast. This study assessed those links using a randomized, double-blind, placebo-controlled design.
  
  
  METHODS
  The visual effects of 1 year of supplementing L (10 mg/d) and Z (2 mg/d) were investigated. One hundred fifteen young, healthy subjects were recruited and randomized into the study (58 received placebo, 57 L+Z). Several dependent measures were collected at baseline and then once every 3 months: serum L and Z measured by HPLC chromatography; MPOD measured using customized heterochromatic flicker photometry; photostress recovery assessed by measuring the time needed to recover visual acquisition of a grating target after 30 seconds of an intense xenon white flash exposure; glare disability evaluated as the energy in a surrounding annulus necessary to veil a central grating target; and chromatic contrast assessed by measuring thresholds for a yellow grating target superposed on a 460-nm background.
  
  
  RESULTS
  Macular pigment optical density increased significantly versus placebo at all eccentricities (10, 30, 60, and 105 minutes from the center of the macula). Serum L and Z also increased significantly by the first follow-up visit (at 3 months), and remained elevated throughout the intervention period of 1 year. Chromatic contrast and photostress recovery time improved significantly versus placebo. Glare disability was correlated with macular pigment density throughout the study period but did not increase significantly in the treated group.
  
  
  CONCLUSIONS
  Daily supplementation with L+Z resulted in significant increase in serum levels and MPOD and improvements in chromatic contrast and recovery from photostress. These results are consistent with past studies showing that increasing MPOD leads to improved visual performance. (ClinicalTrials.gov number, NCT00909090.).
authors.affiliation: Vision Sciences and Human Biofactors Laboratories, Department of Psychology, University of Georgia, Athens, Georgia, United States.
authors.forename: Billy R
authors.initials: BR
authors.lastname: Hammond
authors.affiliation: Vision Sciences and Human Biofactors Laboratories, Department of Psychology, University of Georgia, Athens, Georgia, United States.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Fletcher
authors.affiliation: DSM Nutritional Products Ltd., Wurmisweg, Kaiseraugst, Switzerland.
authors.forename: Franz
authors.initials: F
authors.lastname: Roos
authors.affiliation: DSM Nutritional Products Ltd., Wurmisweg, Kaiseraugst, Switzerland.
authors.forename: Jonas
authors.initials: J
authors.lastname: Wittwer
authors.affiliation: DSM Nutritional Products Ltd., Wurmisweg, Kaiseraugst, Switzerland.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schalch
mesh_terms: D000221:Adaptation, Ocular / Q000502:physiology; D000328:Adult; D003118:Color Perception / Q000187:drug effects* / Q000502:physiology; D015350:Contrast Sensitivity / Q000187:drug effects* / Q000502:physiology; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D019466:Glare; D006801:Humans; D008027:Light / Q000009:adverse effects; D014975:Lutein / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D008266:Macula Lutea / Q000502:physiology; D008297:Male; D020127:Recovery of Function / Q000187:drug effects* / Q000502:physiology; D012168:Retinal Pigments / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects / Q000502:physiology; D014786:Vision Disorders / Q000378:metabolism / Q000503:physiopathology* / Q000517:prevention & control; D055815:Young Adult; D065146:Zeaxanthins / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*
chemical_list: D012168:Retinal Pigments; D065146:Zeaxanthins; D014975:Lutein
keywords: disability glare; lutein; macular pigment; zeaxanthin