Full Title: Diet and supplements in the prevention and treatment of eye diseases
Book: Nutrition in the Prevention and Treatment of Disease (Fourth Edition)
Year of Publication: 2017
Publication Author(s): Julie A Mares, Amy E Millen, Thomas P Lawler, Courtney K Blomme
Nutritional issues in vision health are no longer limited to preventing deficiencies. Over the past 25 years, a large body of evidence has emerged suggesting that vitamin supplements could play a role in treating ocular diseases resulting from genetic mutations, and that diet may slow the progression of diabetic retinopathy and common eye diseases, such as age-related cataract, age-related macular degeneration (AMD), and glaucoma. The eye diseases appear to be, in part, ocular manifestations of broader systemic metabolic stress, oxidative stress, and inflammation. However, there are some unique nutritional needs of eye tissues. These include the dietary carotenoids lutein (and isomers) which selectively and exclusively accumulate in the retina, lens, and many other ocular tissues. These carotenoids improve vision and protect against light damage by absorbing blue wavelengths of light and may also reduce inflammation. Antioxidants (vitamin C and E, lutein, and other eye carotenoids) present in high concentrations in certain ocular tissues play a role in protecting against photooxidative damage. Recent evidence has also emerged to suggest a role of lutein during gestation and infancy. Human milk appears to be a bioavailable source of lutein, but adding of lutein to infant formula is not routine. Setting optimal and safe ranges of intake in infants and pregnant and lactating mothers is an important direction of future research. Zinc is also highly concentrated in the retina and plays multiple roles in eye health. Supplementation with high-dose antioxidants and zinc is considered a standard of care for slowing the progression of AMD. Currently, there is no strong evidence that these or other supplements prevent this disease, or other age-related eye diseases. However, the current body of evidence does suggest that balanced, fruit and vegetable-rich diets are the most prudent means of lowering risk for age-related eye disease and optimizing vision function throughout life.