Purpose: A substantial proportion of the population at risk for visual loss from age-related macular degeneration consumes supplements containing high doses of lutein, but clinical studies to date have shown only modest and variable increases in macular carotenoid pigments in response to supplementation. To determine whether lutein supplementation can indeed alter ocular carotenoid levels, the authors chemically measured levels of lutein, zeaxanthin, and their metabolites in the macula, peripheral retina, and lens of 228 eyes from 147 human donors and correlated these results with retrospective supplement histories from families of selected members of the study population.
Methods: Lenses and circular punches of macula (4-mm diameter) and equatorial peripheral retina (8-mm diameter) were dissected from donor eyes free of ocular disease procured from the local eye bank. The amounts of lutein, zeaxanthin, meso-zeaxanthin, and 3'-oxolutein were determined by HPLC with photodiode array and mass spectral detection.
Results: Eighteen percent of eyes from donors age 48 and older had unusually high levels (66.3 +/- 15.1 ng) of macular carotenoids that were three times the rest of the older population's mean level (23.0 + 12.1 ng; P < 0.001). Carotenoid levels in these outliers were also unusually high in the lens and in the peripheral retina. Similar outliers were not present in donors younger than 48. Most of these outliers regularly consumed high-dose lutein supplements before death. Lutein supplementation was uncommon in older donors whose macular carotenoids were in the normal range.
Conclusions: The presence of unusually high levels of macular carotenoids in older donors who were regularly consuming high-dose lutein supplements supports the hypothesis that long-term lutein supplementation can raise levels of macular pigment. Elevated carotenoid levels in the peripheral retina and lens in these same donors could have important implications for understanding why some clinical methods of macular pigment measurement have had difficulty detecting robust and consistent responses in carotenoid supplementation trials.