Macular pigment is composed of 3 carotenoids, meso-zeaxanthin, lutein and zeaxanthin, and is mainly present at the nerve fiber layers and ganglion cell layers of the retina, with peak concentrations in the fovea. It is thought to function as a blue-light filter and antioxidant, and therefore protect the retina from damaging influences that are thought to play a role in the pathogenesis of age-related macular degeneration.
Lutein is a member of the carotenoid family, which are naturally occurring fat-soluble pigments found in plants. Lutein occurs in numerous foods but the highest concentrations occur in marigolds, which are the source of most of the lutein that is used commercially. Lutein specifically concentrates in the macula, which is a small area in the center of the retina in the eye. The macula lies directly behind the lens and is the area of the eye that receives the most light. Lutein protects the macula by filtering out potentially damaging forms of light. Thus, lutein is associated with protection from various diseases of the eyes, especially age-related macular degeneration, which is a leading cause of blindness in older adults.
Zeaxanthin is one of two carotenoids that occur at high levels in the retina of the eyes, the other being lutein. The greatest amounts of zeaxanthin occur in the macular region, whereas lutein is distributed throughout the entire retina. These carotenoids have two main functions, they absorb the potentially harmful blue-violet wavelengths of light energy that come into the eye, and they also function as antioxidants.
Meso-zeaxanthin is not found in the diet, but is converted in the retina from ingested lutein. When taken as a supplement, meso-zeaxanthin is absorbed into the blood stream and effectively increases macular pigment levels.
A study published in the journal Current Eye Research was designed to measure serum and macular responses to a macular carotenoid formulation containing meso-zeaxanthin (MZ), lutein (L), and zeaxanthin (Z). Five normal subjects and five subjects with early age-related macular degeneration (AMD) were recruited and were instructed to take the carotenoid supplement everyday for eight weeks. After just two weeks of supplementation, there was a significant increase in serum concentrations of MZ and L. The researchers concluded that “We report significant increases in serum concentrations of MZ and L following supplementation with MZ, L, and Z and a significant increase in macular pigment optical density (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.”1
1 Connolly EE, Beatty S, Thurnham DI, et al. Augmentation of macular pigment following supplementation with all three macular carotenoids: an exploratory study. Curr Eye Res. 2010;35(4):335-51.