Abstract
Abstract: :
Purpose: The association between lutein (L), a carotenoid, and eye health is becoming increasingly familiar to the public, but research showing the effects of L supplementation is limited. The purpose of this research was to evaluate the effect of a L supplement on serum carotenoid concentrations and macular pigment optical density (MPOD) profiles in healthy adult volunteers. Methods: This project was a double-blind, placebo-controlled intervention; 7 participants received 6 mg/day L and 6 participants received a placebo for 28 days. Serum carotenoid concentrations were analyzed, and MPOD profiles and 24-hour dietary recalls were assessed at days 0, 7, 14, 21, 28, 56 and 112. Serum carotenoids were analyzed using reversed-phase high performance liquid chromatography. Macular pigment optical density profiles were assessed using a free-view heterochromatic flicker photometry system (Macular Metrics®, Providence, RI). Participants were presented centrally fixed stimuli at four retinal loci; 0.167, 0.5, 1.0 and 2.0 degrees retinal eccentricity and a parafoveal reference loci at 6.0 degrees eccentricity. The 24-hour dietary recalls were analyzed using University of Minnesota Nutrition Data System for Research® software (4.02_30). One-way ANOVA was used to analyze serum carotenoid concentrations and MPOD profiles. Uncorrected Pearson correlations were used to compare reported dietary intake to serum carotenoids and to MPOD. Results: A significant difference in serum L concentration (p=0.016) was found between the L supplement (LS) and placebo (PC) groups. The LS and PC groups' MPOD profiles were not statistically significant. In addition, correlations between serum L concentrations and MPOD profiles were not significantly correlated with reported dietary intake. Conclusion: This study agrees with previous research indicating serum L increases before MPOD. A significant increase in serum L concentrations was observed using just 6 mg L daily for 28 days. It is possible that with a longer intervention, MPOD would increase, suggesting that simple dietary manipulation may result in increased MPOD. Extending the intervention period and including different L doses will help understand the lag time between changes in serum L and MPOD.
Keywords: 462 macular pigment • 337 carotenoids/carotenoid binding proteins