Dietary sodium intake and cataract: the Blue Mountains Eye Study.

A population-based cross-sectional study (n = 2,873) was conducted near Sydney, Australia, from January 1992 to January 1994 to assess the relation between dietary sodium intake and risk of cataract. Photographs of subjects' lenses were graded for cortical, nuclear, and posterior subcapsular cataracts. Dietary sodium intake was assessed with a food frequency questionnaire. The study found that higher sodium intakes were associated with greater risk of posterior subcapsular cataract (p for trend = 0.006). The adjusted relative risk was 2.0 (95% confidence interval: 1.2, 3.4) for subjects in the highest versus the lowest quintile of sodium intake. These findings suggest that a high-salt diet may increase the risk of posterior subcapsular cataract.