Purpose: At the macula, the carotenoids meso-zeaxanthin (MZ), lutein (L), and zeaxanthin (Z) are collectively referred to as macular pigment (MP). This study was designed to measure serum and macular responses to a macular carotenoid formulation.
Materials and methods: Ten subjects were recruited into this study (five normal and five with early age-related macular degeneration [AMD]). Subjects were instructed to consume a formulation containing 7.3 mg of MZ, 3.7 mg of L, and 0.8 mg of Z everyday over an eight-week period. The spatial profile of MP optical density (i.e., MPOD at 0.25 degrees , 0.5 degrees , 1 degrees , and 1.75 degrees ) was measured using customized heterochromatic flicker photometry, and a blood sample was collected at each study visit in order to analyze serum concentrations of MZ, L, and Z.
Results: There was a significant increase in serum concentrations of MZ and L after two weeks of supplementation (p < 0.05). Baseline serum carotenoid analysis detected a small peak eluting at the same time as MZ in all subjects, with a mean +/- SD of 0.02 +/- 0.01 micromol/L. We report significant increases in MPOD at 0.25 degrees , 0.5 degrees , 1 degree , and average MPOD across its spatial profile after just two weeks of supplementation (p < 0.05, for all). Four subjects (one normal and three AMD) who had an atypical MPOD spatial profile (i.e., central dip) at baseline had the more typical MPOD spatial profile (i.e., highest MPOD at the center) after eight weeks of supplementation.
Conclusion: We report significant increases in serum concentrations of MZ and L following supplementation with MZ, L, and Z and a significant increase in MPOD, including its spatial profile, after two weeks of supplementation. Also, this study has detected the possible presence of MZ in human serum pre-supplementation and the ability of the study carotenoid formulation to rebuild central MPOD in subjects who have atypical profiles at baseline.