Over the past few years published reports have provided evidence of decreased rates of lens opacities and/or cataract extraction associated with higher overall intake of antioxidant vitamins. Nevertheless, some ophthalmologists question the added efficacy of using vitamin supplements in addition to healthy eating patterns. The Lens Opacities Case-Control Study (1) and the Nutritional Factors in Eye Disease Study (2), (both reviewed in earlier EduFacts issues) both evaluated the use of multivitamins in addition to overall intake of specific vitamins.

In the Case-control study (1) (See earlier EduFacts: "Vitamin E and Cataracts: Reviewing the Data") cases (any lens opacity in at least one eye explaining a decrease in vision) were compared with controls (no lens opacities, and 20/20 or better in both eyes) with respect to use of multivitamin supplements on a regular basis (at least once a week for at least a year). Regular use of multivitamins was associated with decreased risk of posterior subcapsular, cortical, and nuclear opacities and with decreased risk of mixed opacities.

In the Nutrition and Eye Disease Study (2) 2376 participants in the Beaver Dam Eye Study were evaluated for past multivitamin use then followed forward to determine the current prevalence of lens opacities. Type and severity of lens opacities was determined by comparing (in masked fashion) photos taken under a uniform protocol with a set of photo standards. Among non-diabetic patients (N=1980) past use of multi-vitamins was reported in 21% of people and was associated with a 40% decreased risk of nuclear sclerotic opacities (adjusted for age, sex, smoking and heavy alcohol use). Among smokers risk of nuclear sclerotic opacities was reduced 50%. The protective effect of regular multivitamin use on risk for nuclear sclerotic opacity was significantly stronger in smokers (p<0.05) than in non-smokers. The authors cited reports documenting a higher risk for nuclear cataracts among smokers (who experience more oxidant stress) and suggest that smokers may thus be more susceptible to nutritional modulation of risk.

References

1. Leske MC, Chylack LT Jr, Wu S. The lens opacities case-control study:risk factors for cataract. Arch Ophthalmol 1991;109:244-251.
2. Mares-Perleman JA Klein BEK, et al. Relationship between lens opacities and vitamin and mineral supplement use. Ophthalmology 1994;101:315-325.