Bilberry (Vaccinium myrtillus)
- What it is: A European shrub whose berries and leaves contain potent antioxidants known as anthocyanosides.
- How it works: Bilberry's anthocyanosides serve the body by strengthening collagen fibers and capillaries, especially in the eyes, in part because anthocyanosides have an affinity for the retina. Bilberry improves nighttime vision, helping eyes adjust more quickly to darkness and recover faster from night glare. Bilberry also helps prevent the development of cataracts and diabetic retinopathy and can prevent (and may even treat) macular degeneration (Alternative Medicine Review, 2001, vol. 6, no. 5; Advances in Gerontology, 2005, vol. 16).
- Side effects: None. Used as a food for several centuries, bilberry earns high marks for its safety. For eye protection, 240 to 600 mg daily is ample.
Lutein and zeaxanthin
- What they are: These yellow and orange antioxidant carotenoids color many plants, such as marigolds and corn. Lutein and zeaxanthin are found in the macula, a small area within the retina responsible for central vision, and both help to enhance eyesight.
- How they work: When present in the diet in adequate amounts, lutein and zeaxanthin concentrate in the eye, particularly in the lens and macula, where they filter potentially dangerous elements of sunlight, such as free radicals and near-ultraviolet radiation. Numerous studies show that diets rich in lutein and zeaxanthin reduce the risk of cataracts and age-related macular degeneration, the leading cause of vision loss and blindness in people over 60 (Investigative Ophthalmology and Visual Science, 2006, vol. 47, no. 6; Archives of Ophthalmology, 2006, vol. 124, no. 8). There are no effective treatments for macular degeneration, so prevention is crucial.
- Side effects: No reports of problems from taking these antioxidants in any amount have been made. About 15 mg of a lutein-zeaxanthin supplement per day should protect your eyes. To improve absorption, take it with food that contains a bit of fat.
- What it is: This essential mineral works as an antioxidant, protecting the eyes from exposure to sunlight-related free radicals.
- How it works: Part of the retina, called the retinal pigment epithelium, contains high concentrations of zinc, thought to protect against free radical damage (Journal of the American College of Nutrition, 2001, vol. 20, no. 2 Suppl). Conversely, low zinc levels in the retinal pigment epithelium may correlate with increased free radical damage and the development of macular degeneration. Research indicates that zinc supplements (along with other antioxidants) slow the progression of macular degeneration; high intake of zinc and other antioxidants is associated with a lower risk of developing the disease in the first place (Journal of the American Medical Association, 2005, vol. 294, no. 24).
- Side effects: It's fine to supplement with 50 mg of zinc daily. Keep an eye on total zinc intake, however, because taking more than 150 mg daily could result in a metallic taste, stomach upset, or impaired immune function.
Oregon-based freelancer Victoria Dolby Toews, MPH, is the author of User's Guide to Sexual Satisfaction (Basic Health, 2003) and User's Guide to Glucosamine and Chondroitin (Basic Health, 2002).
The Vision Thing