Abstract
Abstract: :
Purpose: To assess ocular and general safety of supplementation with zeaxanthin, lutein, and their combination and to evaluate concomitant plasma concentrations of carotenoids and the metabolite 3'–dehydro–lutein. Methods: The LUXEA (LUtein Xanthophyll Eye Accumulation) Study is a prospective, single–centered, randomized, double–blind, placebo–controlled, one year pilot supplementation trial with zeaxanthin (OPTISHARPTM) and lutein. For six months, 92 subjects received daily doses of zeaxanthin (Z, 10mg), lutein (L, 10mg), the combination (C, 10mg L+10mg Z), or placebo (P). 14 of these subjects received doubled doses of L or Z or an unchanged dose of C for additional 6 months. Macular pigment optical density (MPOD) was measured monthly by heterochromatic flicker photometry and by a SLO. Plasma concentrations of carotenoids were measured monthly by HPLC. Every three months, clinical chemistry, electro–cardiograms, and ophthalmological parameters, including contrast sensitivity, IOP, color vision, and photostress recovery, were assessed along with anterior and posterior slit lamp biomicroscopic examinations. Results: An at least 5–fold statistically significant increase of xanthophyll (L+Z) plasma concentrations and an overall average MPOD increase of about 9 % across all supplemented groups was observed. The ocular and general safety parameters measured were within normal levels and no severe adverse events occurred. The few reported adverse events were clinically not significant. The longitudinal plasma concentrations of other carotenoids commonly occurring in plasma were not changed. Concentrations of the metabolite 3'–dehydro–lutein reached significantly higher (approximately 2–fold) values with Z than with L supplementation. Conclusions: L and Z supplementation either alone or in combination lead to marked increases of the respective plasma concentrations while those of other common plasma carotenoids remained unchanged. Along with the increase in L and Z plasma concentrations, a modest overall increase of MPOD occurred. The absence of adverse effects documents the apparent general and ocular safety of L and Z at the resulting systemic and ocular exposure levels. The higher 3'–dehydro–lutein plasma levels reached with Z compared to L supplementation could be explained by the Z molecule presenting two identical ends for oxidation to a hypothetical enzyme, whereas the L molecule has only one such end.
Keywords: macular pigment • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled • carotenoids/carotenoid binding proteins