Data from the Lutein, Vision and Mental Acuity II (LAMA II) study indicated that the lutein and zeaxanthin isomers supplement was associated with increases in macular pigment density (MPOD) – an indicator of xanthophyll levels in the eye – and significant improvements in photostress recovery (PSR), and disability glare (DG) thresholds after six months and 12 months.
Photostress recovery is the amount of time the macula requires to return to its normal functioning level after exposure to a bright light source. Disability glare is a degradation of contrast which has been caused by a reduction in visual performance.
“The results of our study, particularly those from the PSR portion, are illustrative of effects elicited by both filtering of light by MPOD, and by retinal physiology enhancement by the [macular carotenoids]. For example, in absolute terms, those with higher MPOD generally had faster PSR times – this was true for each of the 5 exposures and recoveries – but speed of visual recovery was markedly faster and more consistent with successive exposures for those with higher MPOD,” wrote the researchers in Eye and Vision.
The study used the commercially available Lutermax 2020 product at two doses: 10mg lutein and 2 mg zeaxanthin isomers or 20 mg of lutein and 4 mg of zeaxanthin isomers.
Commenting on the study’s findings, Abhijit Bhattacharya, OmniActive’s President, said: “We are delighted that long term studies like LAMA-II demonstrate the practical benefits of macular carotenoid supplementation for general healthy populations- using well-recognized methods and meaningful measures of visual performance.
“OmniActive is dedicated to continue our efforts in bringing relevant and exciting science to support product claims expanding the usage segments and customer categories for our industry.”
The researchers, led by Dr James Stringham from the University of Georgia, recruited 59 healthy young people to participate in LAMA II, a 12 month double-blind, placebo-controlled trial. Participants were randomly assigned to one of the two lutein/zeaxanthin isomers groups or placebo for 12 months.
Results showed that MPOD, visual performance in glare and photostress recovery significantly improved compared with placebo at both Lutemax 2020 doses after 6 months of supplementation with additional improvements found at 12 months.
“The breadth of the impact of the [macular carotenoids] in general, and of MPOD in the retina, continues to expand. The results of our study indicate contributions to visual performance that include aspects of optical filtering and enhancement of retinal metabolism. Although our effects were strong, and correlated to increases in MPOD, we found no differences in any outcome measure between our two dose levels. This may have been due to differences in absorption of the [macular carotenoids], or in retinal uptake and deposition,” wrote the researchers.
“Given all of the health and performance benefits derived from increased systemic and local concentrations of these carotenoids, determining the factors that contribute to absorption, transport, binding, and deposition is perhaps the most urgent scientific question in this area.”
Source: Eye and Vision
2016, 3:30, doi: 10.1186/s40662-016-0060-8
“Macular carotenoid supplementation improves disability glare performance and dynamics of photostress recovery”
Authors: J.M. Stringham et al.