Abstract
Abstract: :
Purpose: High dietary intakes of lutein and docosahexaenoic acid (DHA) and high macular pigment (MP) may be protective against age–related macular degeneration (AMD). Lutein is a main component of MP. DHA is a key fatty acid in the retina. The purpose of this study was to determine individual and combined effects of supplemental lutein (12 mg/d) and DHA (800 mg/d) on their serum levels and MP optical density (MPOD). Methods: Fifty healthy women (60–80 y) were randomly assigned to one of four supplemental groups: placebo, lutein, DHA, and lutein+DHA. Subjects consumed the supplement daily for 4 mos. Blood was collected at 0, 2 and 4 mo and analyzed for lutein and DHA. At baseline and 4 mo, MPOD was determined by heterochromatic flicker photometry at 0.4°, 1.5°, 3° and 5° temporal retinal eccentricities. The parafoveal reference was located at 7° temporal retinal eccentricity. Results: Serum levels of lutein significantly increased from baseline after 2 and 4 mo of lutein supplementation (with or without DHA). No significant changes in serum lutein were observed in the placebo and DHA groups. At 2 mo, the lutein+DHA group had significantly higher serum levels of lutein than all other groups (p <0.05). Serum levels of DHA significantly increased from baseline after 2 and 4 mo of DHA supplementation (with or without lutein) (p < 0.0001). No significant changes of serum DHA were observed for the placebo and lutein groups. In the lutein group, there was an increase in MPOD at the 3.0° (p <0.04) and 5° loci (p <0.05). In the DHA group, there was a significant increase in MPOD at the most central locus (0.4° locus, p <0.04) with no significant changes at other loci. In the combination group (lutein+DHA) there were significant increases in MPOD at the 0.4°, 1.5°, and 3°loci (p <0.04). Conclusions: Supplementation of these elderly women with lutein alone increased MPOD eccentrically whereas DHA supplementation alone resulted in central increases in MPOD. The combination of supplements had a combined effect on MPOD. DHA facilitated accumulation of lutein in the blood. These data may have implications for the use of supplemental lutein and DHA in AMD prevention.
Keywords: macular pigment • age-related macular degeneration • nutritional factors