Nutritional manipulation of primate retinas, I: effects of lutein or zeaxanthin supplements on serum and macular pigment in xanthophyll-free rhesus monkeys.
OBJECTIVE
The xanthophylls lutein (L) and zeaxanthin (Z) are the primary components of macular pigment (MP) and may protect the macula from age-related degeneration (AMD). In this study, L or Z was fed to rhesus monkeys reared on xanthophyll-free diets to follow the accumulation of serum carotenoids and MP over time.


METHODS
Eighteen rhesus monkeys were fed xanthophyll-free semipurified diets from birth until 7 to 16 years. The diets of six were then supplemented with pure L and six with pure Z at 3.9 micromol/kg per day (2.2 mg/kg per day) for 24 to 56 weeks. At baseline and 4- to 12-week intervals during supplementation, serum carotenoids were measured by HPLC, and MP density was estimated by two-wavelength reflectometry. Serum carotenoids and MP were also measured in monkeys fed a stock diet.


RESULTS
Monkeys fed xanthophyll-free diets had no L or Z in serum and no detectable MP. During supplementation, serum L or Z increased rapidly over the first 4 weeks and from 16 weeks onward maintained similar levels, both several times higher than in stock-diet-fed monkeys. The central peak of MP optical density increased to a relatively steady level by 24 to 32 weeks in both L- and Z-fed groups. Rhesus monkeys fed a stock diet had lower blood concentrations of L than those found in humans and other nonhuman primates.


CONCLUSIONS
Rhesus monkeys respond to either dietary L or Z supplementation with increases in serum xanthophylls and MP, even after life-long xanthophyll deficiency. These animals provide a potential model to study mechanisms of protection from AMD.
Neuringer
Martha
M
Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Portalnd 97006, neuringe@ohsu.edu.
Sandstrom
Marita M
MM
Johnson
Elizabeth J
EJ
Snodderly
D Max
DM
D000818:Animals; D002338:Carotenoids / Q000097:blood*; D019587:Dietary Supplements; D014975:Lutein / Q000008:administration & dosage*; D008253:Macaca mulatta; D008266:Macula Lutea / Q000378:metabolism*; D012168:Retinal Pigments / Q000378:metabolism*; D024341:Xanthophylls / Q000172:deficiency*; D065146:Zeaxanthins; D019207:beta Carotene / Q000008:administration & dosage* / Q000031:analogs & derivatives
D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D014975:Lutein