Relation between dietary n-3 and n-6 fatty acids and clinically diagnosed dry eye syndrome in women

Background: Dry eye syndrome (DES) is a prevalent condition, but information on risk or protective factors is lacking. Objective: We aimed to determine the association between the dietary intake and ratio of n-3 and n-6 fatty acids (FAs) and DES occurrence. Design: Of the 39 876 female health professionals in the Women's Health Study (WHS), 32 470 women aged 45-84 y who provided information on diet and DES were cross-sectionally studied. We assessed FA intakes by using a validated food-frequency questionnaire and assessed DES by using self-reports of clinically diagnosed cases. Of the sample, 1546 (4.7%) subjects reported DES. We used logistic regression models to estimate the odds ratios (ORs) and 95% CIs to describe the relation of FA intake with DES. Results: After adjustment for demographic factors, hormone therapy, and total fat intake, the OR for the highest versus the lowest quintile of n-3 FAs was 0.83 (95% CI: 0.70, 0.98; P for trend = 0.05). A higher ratio of n-6 to n-3 FA consumption was associated with a significantly increased risk of DES (OR: 2.5 1; 95 % CI: 1.13, 5.58) for > 15:1 versus <4:1 (P for trend = 0.01). In addition, tuna consumption [1 serving was 113 g (4 oz)] was inversely associated with DES (OR: 0.81; 95% CI: 0.66, 0.99 for 2-4 servings/wk; OR: 0.32; 95% CI: 0.13, 0.79 for 5- 6 servings/wk versus <= 1 serving/wk; P for trend = 0.005). Conclusions: These results suggest that a higher dietary intake of n -3 FAs is associated with a decreased incidence of DES in women. These findings are consistent with anecdotal clinical observations and postulated biological mechanisms.