title: Nutritional manipulation of primate retinas, III: Effects of lutein or zeaxanthin supplementation on adipose tissue and retina of xanthophyll-free monkeys.
abstract: OBJECTIVE
  Macular pigment (MP) is composed of the xanthophylls lutein (L) and zeaxanthin (Z) and may help to prevent age-related macular degeneration or retard its progression. In this study the effects of L or Z supplementation on carotenoid levels was examined in serum, adipose tissue, and retina in rhesus monkeys with no previous intake of xanthophylls.
  
  
  METHODS
  From birth to 7 to 16 years of age, 18 rhesus monkeys were fed semipurified diets containing all essential nutrients but no xanthophylls. Six were supplemented with pure L and 6 with pure Z at 3.9 micromol/kg per day for 24 to 101 weeks. At baseline and at 4- to 12-week intervals, carotenoids in adipose tissue were measured by HPLC. At study completion, carotenoids in serum and retina (central 4 mm, 8-mm annulus, and the periphery) were determined. Results were compared with data from control monkeys fed a standard laboratory diet.
  
  
  RESULTS
  Monkeys fed xanthophyll-free diets had no L or Z in serum or tissues. After L or Z supplementation, serum and adipose tissue concentrations significantly increased in the supplemented groups. Both L and 3R,3'S-Z (RSZ or meso-Z, not present in the diet) were incorporated into retinas of monkeys supplemented with L, with RSZ present only in the macula (central 4 mm). All-trans Z, but no RSZ, accumulated in retinas of monkeys supplemented with Z.
  
  
  CONCLUSIONS
  L is the precursor of RSZ, a major component of macular pigment. Xanthophyll-free monkeys can accumulate retinal xanthophylls and provide a valuable model for examining their uptake and conversion.
authors.affiliation: Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA. elizabeth.johnson@tufts.edu
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Johnson
authors.forename: Martha
authors.initials: M
authors.lastname: Neuringer
authors.forename: Robert M
authors.initials: RM
authors.lastname: Russell
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schalch
authors.forename: D Max
authors.initials: DM
authors.lastname: Snodderly
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002338:Carotenoids / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D014975:Lutein / Q000008:administration & dosage* / Q000378:metabolism; D008253:Macaca mulatta; D008297:Male; D012160:Retina / Q000378:metabolism*; D012168:Retinal Pigments / Q000378:metabolism; D024341:Xanthophylls / Q000172:deficiency*; D065146:Zeaxanthins; D019207:beta Carotene / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D014975:Lutein