Boston’s Brigham and Women’s Hospital, the Schepens Eye Research Institute, the Massachusetts Eye and Ear Infirmary and Harvard Medical School conducted a study aimed at determining the association between the dietary intake and ratio of n-3 and n-6 fatty acids and dry eye syndrome occurrence in women.

The cross-sectional study included 32,470 women aged 45 to 84 years old who provided information on diet and dry eye syndrome, drawn from 39,876 female health professionals in the Women’s Health Study (WHS). Researchers assessed fatty acid intakes using a validated food-frequency questionnaire and assessed dry eye syndrome using self-reports of clinically diagnosed cases. Of the sample, 1,546 subjects (4.7 percent) reported dry eye syndrome. Researchers used logistic regression models to estimate the odds ratios and 95 percent confidence intervals to describe the relation of fatty acid intake with dry eye syndrome.

After adjustments for demographic factors, hormone therapy and total fat intake, the odds ratio for the highest vs. the lowest quintile of n-3 fatty acids was 0.83. A higher ratio of n-6 to n-3 fatty acid consumption was associated with a significantly increased risk of dry eye syndrome for greater than 15 to 1 vs. less than 4 to 1. In addition, tuna consumption (one serving = 113 g or 4 oz.) was inversely associated with dry eye syndrome. The results suggest that a higher dietary intake of n-3 fatty acids is associated with a decreased incidence of dry eye syndrome in women. The findings are consistent with anecdotal clinical observations and postulated biological mechanisms.