ANTIOXIDANT VITAMINS AND NUCLEAR OPACITIES - THE LONGITUDINAL-STUDY OF CATARACT

Objective: The association of antioxidant nutrients and risk of nuclea r opacification was evaluated in the Longitudinal Study of Cataract. D esign: Nutritional data were collected at baseline on the 764 particip ants, which included assessment of dietary intake, use of vitamin supp lements, and plasma levels of vitamin E. Ophthalmologic and other data were collected at baseline and at yearly follow-up visits, including lens photographs, which were graded using the Lens Opacities Classific ation System III protocol. Main Outcome Measures: Analyses examined wh ether the nutritional factors at baseline were related to increases in nuclear opacification at follow-up. The MULCOX2 approach, an extensio n of the Cox regression model, was used. Results are presented as rela tive risks (RRs) and 95% confidence intervals. Intervention: Intervent ion was not applicable. Results: The risk of nuclear opacification at follow-up was decreased in regular users of multivitamin supplements ( RR = 0.69; 0.48-0.99), vitamin E supplements (RR = 0.43; 0.19-0.99), a nd in persons with higher plasma levels of vitamin E (RR = 0.58; 0.36- 0.94). Conclusions: In regular users of multivitamin supplements, the risk of nuclear opacification was reduced by one third; in regular use rs of vitamin E supplements and persons with higher plasma levels of v itamin E, the risk was reduced by approximately half. These results ar e similar to those obtained in our earlier case-control study. Because these data are based on observational studies only, the results are s uggestive but inconclusive. The possible effect of nutritional supplem ents on the lens requires confirmation by ongoing clinical trials.