DOSE RANGING STUDY OF LUTEIN SUPPLEMENTATION IN ELDERLY WITH AND WITHOUT AGE RELATED MACULAR DEGENERATION

Abstract

Age-related macular degeneration (AMD) is the leading cause of blindness among people over the age of 65. Epidemiological studies have indicated that people with a high intake of two dietary carotenoids, lutein and zeaxanthin that accumulate in the human macula, are at a reduced risk of AMD. Possible role of lutein and zeaxanthin in the prevention of AMD has been attributed to their antioxidant function and their ability to act as optical filters. The objectives of this study were to investigate the association between three doses of orally ingested lutein supplements and serum levels of this carotenoid in elderly with and without AMD; to evaluate the possible interaction between supplemental lutein and other dietary carotenoids, retinol, and tocopherol; to correlate the serum levels of lutein with the total macular pigment optical density (MPOD).

Forty-five subjects over the age of 60 were divided into 3 groups: subjects without AMD and subjects with middle and end stage of AMD. Subjects in each group were randomized to receive one of the three doses of 2.5, 5, and 10 mg/day of lutein (containing 5% zeaxanthin) for 6 months. Subjects were followed up for 6 months. Carotenoids and their metabolites in the serum of subjects were analyzed by HPLC at weeks 0, 1, 4, 12, 26, 38, and 52. The MPOD of subjects was measured by Heterochromatic Flicker Photometry (HCFP). The data were analyzed using analysis of variance and covariance with repeated measurements (SAS, version 8.2).

The mean serum concentrations of lutein in all subjects increased with supplementation. Subjects receiving 10 mg/day of lutein had a 3-4 fold increase in their serum levels of lutein, while those receiving 2.5 and 5 mg/day dose had approximately 2 fold increase. In conclusion, the serum concentration of lutein appears to be dose dependent and the presence or the absence of AMD does not interfere with the serum levels of this carotenoid. Supplemental lutein does not interact with other dietary carotenoids, retinol, and tocopherol. The results from MPOD measurements by HCFP were inconsistent and could not be used to reach any conclusion with regard to MPOD changes.