Zinc (1988, 1996, 2017) and Macular Degeneration
The mineral zinc plays an important role in the bioavailability and behavior of certain zinc-dependent enzymes in the eye. Reseachers have found associations between low zinc levels and retinal and macular degredation.
A review of the many studies and trials finds consensus in the understanding that low zinc levels are tied to retinal and macular problems and that supplementation including zinc is associated with slowing the advance of the condition.
While antioxidant supplementation has beneficial results for some people, and omega-3 supplementation needs to be further researchers, the benefit from supplementing with C, E, beta-carotene and zinc is now known. Genetic factors may affect the benefit of the other nutrients.
The AREDS study in 2001 first identified the relationship between zinc levels and AMD. The study participants were followed over the course of many years and zinc alone or in combination with antioxidants slowed the progression of advanced AMD.
Results from AREDS2 in 2006 confirmed zinc's importance and substituted lutein and zeaxanthin for beta-carotene.
Like antioxidants, zinc is very much present in the retina, especially in the macula.
Seafood and meat products generally supply enough zinc for the diet (recommended 11mg/day for men and 8mg/day for women). It is present in beans, grains and nuts, but absorption is poor and the body does not store zinc effectively. High doses of zinc interfere with copper absorption, so the AREDs formulation includes 2 mg/day of copper.
Zinc apparently operates by contributing to the beneficial action of many enzymes in the eye and helps to suppress inflammation.
Reviewers: A. Carneiro and J.P. Andrade,
Published: Nutritional and Lifestyle Interventions for Age-Related Macular Degeneration: A Review, Oxidative Medicine and Cellular Longevity, January, 2017.
That zinc deficiencies contribute to retina/macular deterioration was one of the results from the data collected by the large Beaver Dam study which was published in 1996. The Beaver Dam study was a longitudinal study over ten years that investigated the dietary and other habits of nearly 5000 patients with macular degeneration.
Researchers: J.A. Mares Perlman, et al.
Published: Association of zinc and antioxidant nutrients with age-related maculopathy. Archives of Ophthalmology, August, 1996
Researchers investing the effect of supplementation with zinc in macular degeneration patients found that the patients receiving zinc had markedly less loss of vision.
Researchers: D.A. Newsome, et al, Louisiana State University
Published: Oral zinc in macular degeneration, Archives of Opthalmology, 1988.