Abstract
Purpose: :
At the macula, the carotenoids meso-zeaxanthin (MZ), lutein (L) and zeaxanthin (Z) are collectively referred to as macular pigment (MP). To date only one study has reported on MP augmentation following supplementation with MZ, L and Z. However, that study measured only one retinal location (0.75°) and may not have been able to detect changes, if any, at other degrees of retinal eccentricity. Our study was designed to investigate (in a double-blind, randomized placebo controlled fashion) changes in MP optical density (MPOD, including its entire spatial profile), and serum concentrations of the macular carotenoids in response to supplemental MZ, L and Z in healthy subjects.
Methods: :
We recruited 44 healthy subjects for this study. 22 subjects were randomized to consume a formulation containing 10.6 mg of MZ, 5.9 mg of L and 1.2 mg of Z (Intervention [I] group), and 22 subjects consumed a placebo everyday over a six month period (Pleacebo [P]) group). At each study visit (Baseline [V1], 3 months [V2], and 6 months [V3]) the spatial profile of MPOD (i.e. at 0.25°, 0.5°, 1° and 1.75°) was measured using customised heterochromatic flicker photometry and a blood sample was collected to analyse serum concentrations of L and Z using high performance liquid chromatography.
Results: :
The mean ± SD age of our subjects was 43.54 ± 12.2. There was a statistically significant increase in serum concentrations of L and Z (µmol/L) and MPOD at 0.25° and 0.5° retinal eccentricity at V2 and V3 in the I group (p 0.05, for all).
Conclusions: :
Our findings are consistent with previous supplementation studies that have shown increases in serum concentrations of L and Z and MPOD following supplementation with the macular carotenoids. Interestingly, the greatest increase seen in this study was at the centre (0.25°) following supplementation with an MZ dominant formulation.
Clinical Trial: :
www.ISRCTN.org ISRCTN60816411
Keywords: macular pigment • age-related macular degeneration • antioxidants