Serum response to supplemental macular carotenoids in subjects with and without age-related macular degeneration

Abstract

Macular pigment (MP) is composed of lutein (L), zeaxanthin (Z) and meso-zeaxanthin (MZ). The present study reports on serum response to three different MP supplements in normal subjects (n 27) and in subjects with age-related macular degeneration (AMD) (n 27). Subjects were randomly assigned to: Group 1 (20 mg L and 2 mg Z), Group 2 (10 mg L, 2 mg Z and 10 mg MZ) or Group 3 (3 mg L, 2 mg Z and 17 mg MZ). Serum carotenoids were quantified at baseline, and at 4 and 8 weeks using HPLC. Response data for normal and AMD subjects were comparable and therefore combined for analysis. We report response as the average of the 4- and 8-week concentrations (saturation plateau). Serum L increased significantly in Group 1 (0·036 μmol/l per mg (269 %); P< 0·001) and Group 2 (0·079 μmol/l per mg (340 %); P< 0·001), with no significant change in Group 3 (0·006 μmol/l per mg (7 %); P= 0·466). Serum Z increased significantly in Group 1 (0·037 μmol/l per mg (69 %); P= 0·001) and Group 2 (0·015 μmol/l per mg (75 %); P< 0·001), with no significant change in Group 3 ( − 0·0002 μmol/l per mg ( − 6 %); P= 0·384). Serum MZ increased significantly in Group 1 (0·0094 μmol/l (absolute value); P= 0·015), Group 2 (0·005 μmol/l per mg; P< 0·001) and Group 3 (0·004 μmol/l per mg; P< 0·001). The formulation containing all three macular carotenoids (Group 2 supplement) was the most efficacious in terms of achieving the highest combined concentration of the three MP constituent carotenoids in serum, thereby potentially optimising the bioavailability of these compounds for capture by the target tissue (retina).