Vitamin E and Cataracts

Vitamin E and Cataracts There is good evidence that cataracts are the result of oxidative damage to a-crystaUin in the lens of the eyes, and therefore high intakes of antioxidants might be expected to be beneficial. Of 10 controlled trials, 5 showed a protective effect of vitamin E supplements, and 5 showed no effect (Institute of Medicine, 2000). 

Bravetti G. Preventive medical treatment of senile cataract with vitamin E and anthocyanosides clinical evaluation. Ann Opthalmol Clin Ocul 1989 115 109-116. 

Compelling support for the involvement of free radicals in disease development comes from epidemiological studies showing that an enhanced antioxidant status is associated with reduced risk of several diseases. Vitamin E and prevention of cardiovascular disease is a notable example. Elevated antioxidant status is also associated with decreased incidence of cataracts and cancer, and some recent reports have suggested an inverse correlation between antioxidant status and occurrence of rheumatoid arthritis and diabetes... 

Vitamin E Status of Humans. As hypovitaminosis E is a rare event (see D), a routine assessment of the vitamin E status in humans is not required but only justified for risk groups (e.g., prematures) and as part of studies on the chemoprevention of diseases presumably involving oxidative stress as an etiological factor, e.g., cancer, atherosclerosis, and cataract. Knowledge about the in vivo fate of vitamin E (see C) will guide in the choice of samples to be analyzed. The most common, easily obtainable biological matrix for the determination of vitamin E and of a-tocopherol in particular is plasma/serum. Plasma levels of Y-tocopherol, which is more abundant in foods, are of little importance except... 

Cambridge Heart Antioxidant Study DATATOR Deprenyl and Tocopherol Antioxidative Therapy of Rarkinsonism FMC, Finnish Mobile Clinic Health Examination Survey GISSI, Gruppo Italiano Studio Soprawivenza Infarto HOPE, Heart Outcome Prevention Evaluation HPFS, Health Professional Follow-up Study NHS, Nurses Health Study PPR Primary Prevention Project SPACE, Secondary Prevention with Antioxidants of Cardiovascular disease in End-stage renal disease VEAPS, Vitamin E Atherosclerosis Prevention Study VECAT Vitamin E Cataract Age-related maculopathy Trial. 

McNeil JJ, Robman L, Tikellis G, et al. Vitamin E supplementation and cataract randomized controlled trial. Ophthalmology 2004 I I 1 75-84. 

A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E and beta carotene for age related cataract and vision loss AREDS report no. 9. Arch Ophthalmol 2001 I 19 1439-1452. 

Animal studies show some protective effects of tocopherol supplements against a variety of radical-generating chemical toxicants, and it has been assumed that vitamin E may similarly be protective against a variety of degenerative diseases that are associated with radical damage, including cancer, cardiovascular disease, cataracts, and neurodegenerative diseases. 

Robertson J, Donner AP, Trevithick JR. 1989. Vitamin E intake and risk of cataracts in humans. 

Prospective cohort studies were not able to relate vitamin C with lens opacities. In the Baltimore Longitudinal Study on Aging, plasma ascorbic acid was not inversely associated with risk, but vitamin E was (Vitale et al., 1993). In the Women s Health Study and the Physicians Health Study of Harvard University, Boston, vitamin C intake did not show a meaningful relationship to risk (Hankinson et al., 1992 Seddon et al., 1994). A modest reduction in risk was found with multivitamin use in men. Also the Italian-American Cataract Study Group (1991) did not find a significant reduction in risk for any nutrient studied, including vitamin C. 

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