It is believed that Lutein, Zeaxanthin and Meso-Zeaxanthin in the macula block blue light from reaching the underlying structures in the retina, thereby reducing the risk of light-induced oxidative damage that could lead to macular degeneration (AMD).
A number of studies have found that Lutein and Zeaxanthin either help prevent AMD or may slow progression of the disease:
- Research published in Nutrition & Metabolism found that a nutritional supplement containing meso-zeaxanthin, lutein and zeaxanthin effectively increased the optical density of the macular pigment in eyes of the majority of human subjects. The macular pigment is believed to offer protection against the development of macular degeneration.
- Studies published in American Journal of Epidemiology, Ophthalmology and Archives of Ophthalmology found higher levels of lutein and zeaxanthin in the diet are associated with a lower incidence of AMD.
- Two studies published in Investigative Ophthalmology and Visual Science found that eyes with greater levels of macular pigments were less likely to have or develop macular degeneration.
- In research published in Archives of Biochemistry and Biophysics, the study authors conclude that lutein, zeaxanthin and meso-zeaxanthin filter short-wavelength light and prevent or reduce the generation of free radicals in the retinal pigment epithelium and choroid. They also suggest that a mixture of these carotenoids is more effective than any one of the individual carotenoids at the same total concentration.
- In a study published in the journal Optometry, participants with early AMD who consumed 8 mg per day of dietary zeaxanthin for one year improved their night driving and their visual acuity improved an average of 1.5 lines on an eye chart.