title: Biologic mechanisms of the protective role of lutein and zeaxanthin in the eye.
abstract: The macular region of the primate retina is yellow in color due to the presence of the macular pigment, composed of two dietary xanthophylls, lutein and zeaxanthin, and another xanthophyll, meso-zeaxanthin. The latter is presumably formed from either lutein or zeaxanthin in the retina. By absorbing blue-light, the macular pigment protects the underlying photoreceptor cell layer from light damage, possibly initiated by the formation of reactive oxygen species during a photosensitized reaction. There is ample epidemiological evidence that the amount of macular pigment is inversely associated with the incidence of age-related macular degeneration, an irreversible process that is the major cause of blindness in the elderly. The macular pigment can be increased in primates by either increasing the intake of foods that are rich in lutein and zeaxanthin, such as dark-green leafy vegetables, or by supplementation with lutein or zeaxanthin. Although increasing the intake of lutein or zeaxanthin might prove to be protective against the development of age-related macular degeneration, a causative relationship has yet to be experimentally demonstrated.
authors.affiliation: Department of Biochemistry, School of Medicine and the USDA Jean Mayer Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111-1837, USA. norman.krinsky@tufts.edu
authors.forename: Norman I
authors.initials: NI
authors.lastname: Krinsky
authors.forename: John T
authors.initials: JT
authors.lastname: Landrum
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bone
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology; D000975:Antioxidants / Q000378:metabolism; D002386:Cataract / Q000178:diet therapy* / Q000517:prevention & control; D006801:Humans; D014975:Lutein / Q000008:administration & dosage / Q000737:chemistry / Q000502:physiology*; D008266:Macula Lutea / Q000737:chemistry*; D008268:Macular Degeneration / Q000178:diet therapy* / Q000517:prevention & control; D012160:Retina / Q000187:drug effects; D012168:Retinal Pigments / Q000032:analysis / Q000737:chemistry / Q000502:physiology; D012307:Risk Factors; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000502:physiology*
chemical_list: D000975:Antioxidants; D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; C584722:meso-zeaxanthin; D014975:Lutein