Serum carotenoids and tocopherols and incidence of age-related nuclear cataract

Background: It is not known whether the protective effects of antioxidants on cataract observed in experimental animals are relevant to age-related op acities in humans. Objective: The relations of serum carotenoids and tocopherols to the incide nce of age-related nuclear cataract were investigated in a random sample of 400 adults, 50-86 y of age, in the Beaver Dam Eye Study. Design: Nuclear opacity was assessed by using lens photographs taken at bas eline (in 1988-1990) and follow-up (in 1993-1995). Nonfasting concentration s of individual carotenoids and alpha- and gamma-tocopherol, were determine d from serum obtained at baseline. A total of 252 persons were eligible for incident cataract, of whom 57 developed nuclear cataract in at least one e ye. Results were adjusted for age, smoking, serum cholesterol, heavy drinki ng, adiposity, and, in the tocopherol models, dietary linoleic acid intake. Results: Only serum tocopherol (the sum of alpha- and gamma-tocopherol, in mu mol/mmol cholesterol) was associated with cataract. For total serum toco pherol, persons in tertile 3 had a lower risk of cataract than persons in t ertile 1 [odds ratio (OR): 0.4; 95% CI: 0.2, 0.9; P = 0.03 for linear trend ]. Although serum carotenoids were not significantly associated with nuclea r cataract, marginal inverse associations with lutein (OR: 0.3; 95% CI: 0.1 , 1.2: P = 0.13 for linear trend) and cryptoxanthin (OR: 0.3; 95% CI: 0.1, 1.3; P = 0.11 for linear trend) were suggested in people greater than or eq ual to 65 y of age. Conclusions: Findings were compatible with the possibility that nuclear cat aract may be linked inversely to vitamin E status, but neither strongly sup ported nor negated the hypothesized inverse association of nuclear cataract with serum carotenoids.