The apple of my eye. An eye for an eye. Eye contact. Eye-opener. The eye figures prominently in our idioms because it is the most treasured of our five senses. As we age, however, that precious faculty tends to diminish, and an increasing number of people will experience vision problems in their lifetimes. Cataracts and macular degeneration are the leading causes of blindness in the United States and, unless we take preventive measures, these figures will only rise as the average lifespan increases.
In light of our increased longevity and heightened chance of vision impairment, researchers are exploring the role certain nutrients may play. in keeping eyes healthy and retarding eye damage. As with so many health conditions today, it seems that antioxidants are the key.
Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly. The macula is a portion of the retina in the back of the eye responsible for focusing. Sunlight triggers oxidative damage in the eye, which in turn can cause the macula to break down over time.
It makes sense, then, that antioxidants can prevent or reduce this damage. Lutein and zeaxanthin are carotenoids that concentrate around the macula and protect it from harmful sunlight. Researchers from Harvard's Massachusetts Eye and Ear Infirmary report that people who consumed about 5.8 mg of lutein and zeaxanthin per day have a 57% decreased risk of macular degeneration compared to those who took in little of these. The well-known antioxidant, vitamin A, seems to be helpful as well. Ginkgo biloba also acts as an antioxidant in the eye and has been found helpful for AMD. Bilberry contains anthocyanosides, antioxidant compounds that protect the retina, which may prove helpful against AMD. In addition to its antioxidant feature, bilberry also reduces hemorrhaging in the retina and strengthens capillaries.
Cataracts are cloudy spots on the lenses of the eyes that impair vision. People over 60 years of age are at a high risk for developing cataracts, as are smokers, diabetics and those exposed to extreme sunlight. These oxidative stresses appear to cause cataracts. Other factors may include iris color, hypertension and drug exposure. Cataract surgery is quite effective but carries risks, as all surgeries do, so researchers are putting effort into preventing its formation.
Once again, antioxidants help prevent this condition. Vitamin C and glutathione are the primary antioxidants in the lens. Vitamin C activates vitamin E, which then activates glutathione. Proper levels of vitamin C have been linked to a lower risk of developing cataracts, and research has shown that people with low blood levels of vitamin E have 3.7 times the risk of forming, cataracts compared to people with high blood vitamin E levels.
Supplementing with these vitamins can be an important step in protecting the lens, particularly because vitamin C levels in the eye decrease with age.
Bilberry protects the lens and the retina from oxidative damage. Its compounds also help the eyes adapt to bright light and improve night vision. Two studies showed that the antioxidant activity of billberry's compounds seems to reduce the risk of cataracts.
A study in vitamins
A multi-center, long-range study off the role of antioxidants in eye health ts entering its final phase. The National Eye Institute recruited over 4,700 patients nationwide to participate in the Age-Related Eye Disease Study (AREDS), which focuses on AMD and cataract. Study participants receive high doses of vitamins C, E and betacarotene and the minerals zinc and copper.
Rick Ferris, MD, opthalmologist and AREDS chairman, says that if lutein had been commercially available at the time the study began, he would have included it. "Lutein quenches free radical formation and is essential to plants. If you remove it, they die--it's a powerful antioxidant." He explains that while vitamin A is necessary for the proper function of the eye's photoreceptors, beta-carotene serves as an antioxidant for the eye, so it was chosen over its vitamin cousin. Results of the study are expected in September 2001.
Our Vision Supplement Kit
Vitamins C & E
Risk Factors for Mascular Degeneration
Excess UV high exposure
Too much saturated fat
Not enough Lutein and Zeaxanthin
Not enough Lycopene
Too much alcohol
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Jacques PF, et al. "Antioxidant status in persons with and without senile cataract," Arch Ophthalmol 106:337-40, 1988.
Lebuisson DA, Leroy L, Rigal G. "Treatment of senile macular degeneration with Ginkgo biloba extract," Presse Med 25;15(31):1556-8, Sep. 1986.
Rouhiainen P, Rouhiainen H, Salonen JT. "Association between low plasma viatamin E concentration and progression of early cortical lens opacities," Am J Epidemiol 144:496-500, 1996.
Salvayre R, Braquet P, et al. "Comparison of the scavenger effect of bilberry anthocyanosides with various flavonoids," Proceed Intl Bioflavonoids Symposium, Munich, 437-42, 1981.
Seddon JM, et al. "Dietary carotenoids, vitamins A, C, and E, and advanced age-related macular degeneration," JAMA 272:1413-20, 1994.
By Heath Davis Havlick