Vitamin E
Vitamin E in its most biologically active form is a powerful antioxidant found in nuts, fortified cereals and sweet potatoes. It is thought to protect cells of the eyes from damage caused by unstable molecules called free radicals, which break down healthy tissue.AMD and cataract incidence are growing. Worldwide, more than 25 million people are affected by age-related macular degeneration (AMD) and the formation of cataracts. AMD is the leading cause of blindness in people over age 55 in the Western world and the incidence is expected to triple by 2025 as the population ages.
Benefits to Eye Health
Studies indicate that vitamin E reduces the progression of AMD and cataract formation. Vitamin E also plays a significant role in the immune system, the health of cell membranes, in DNA repair, and in other metabolic processes. The human body does not synthesize the vitamin E it needs, which is the reason nuts, salad and vegetable oils are essential to good nutrition. Daily intake of vitamin E through diet, nutritional supplements, or fortified foods and beverages is important for the maintenance of good eye health.
Vitamin E and Cataracts
Studies have indicated that cataract formation also may be delayed by supplementing the diet with vitamin E. A recent study demonstrated that higher dietary intakes of lutein and zeaxanthin and vitamin E were associated with significantly decreased risks of cataracts.
Vitamin E and Age-Related Macular Degeneration (AMD)
The Age-Related Eye Disease Study (or AREDS), sponsored by the National Eye Institute, was a landmark study that established AMD as a ‘nutrition responsive disorder.’ The study showed that a 400 IU/day intake of vitamin E, taken with antioxidants beta-carotene, vitamin C and zinc supplementation, slows the progression of advanced age-related macular degeneration (AMD) by about 25 percent in individuals at high-risk for the disease. Emerging science, consisting of the AREDS results and seven smaller studies, have confirmed these results.
Daily Intake*
The U.S. Food and Drug Administration (FDA) has established a dietary reference intake (DRI) for vitamin E to be 22 IU per day for both males and females. Diets low in fat can significantly decrease vitamin E intake. In adults, symptoms of vitamin E deficiency include nerve damage, muscle weakness, poor coordination, involuntary movement of the eyes and breaking of red blood cells leading to anemia. Vitamin E is a fat soluble supplement that should not be taken in excess by anyone taking supplements or medications that have blood thinning qualities.
Food Sources
Most Western diets are low in vitamin E, which can be found in nuts, salad and vegetable oils, peanut butter, fortified cereals and sweet potatoes. The table above lists foods known to be high in vitamin E antioxidants. Always consult with a health care professional before beginning a supplementation regiment.
References
- (2001). "A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age- related macular degeneration and vision loss: AREDS report no. 8." Arch Ophthalmol119(10): 1417-36.
- Chiu, C. J. and A. Taylor (2007). "Nutritional antioxidants and age-related cataract and maculopathy." Experimental eye research84(2): 229-45.
- Chew, E. (2007). “Age-related eye disease study 2 protocol.” National Eye Institute Protocol 07-EI-0025.
- U.S. Department of Agriculture, Agricultural Research Service, USDA Nutrient Data Laboratory. USDA National Nutrient Database for Standard Reference, Release 20 (2007). Nutrient Data Laboratory Home Page, http://www.nal.usda.gov/fnic/foodcomp.
- Christen, W.G., S. Liu, et al . (2008). “Dietary carotenoids, vitamins C and E, and risk of cataract in women: a prospective study.” Archives of Ophthalmology 126(1): 102-9.
- Evans J, Antioxidant supplements to prevent or slow down the progression of AMD: a systematic review and meta-analysis, Eye. 2008 Jun; 22(6):751-60. Epub 2008 Apr 18.
*At this time, the AOA is unaware of any studies that have examined interactions between specific medications and vitamin E. The AOA also is not aware of any adverse health reports from interactions between specific medications and vitamin E. However, the AOA recommends consulting with a health care professional before beginning any supplementation regiment.