Omega-3 fatty acids linked to lower dry eye incidence in women

A high dietary intake of omega-3 fatty acids seems to have a protective effect against dry eye syndrome in women, a large-scale study found.

Biljana Miljanovic, MD, and colleagues at Brigham and Women’s Hospital in Boston analyzed data from surveys filled out by 32,470 women between 45 and 84 years old in the Women’s Health Study. The researchers assessed fatty acid intake by using a validated food-frequency questionnaire and assessed dry eye using self-reports from the participants.

After adjusting for demographic factors, hormone therapy and total fat intake, the odds ratio for dry eye in the highest vs. the lowest quintile of omega-3 fatty acid intake was 0.83. A higher ratio of omega-6 to omega-3 fatty acid intake was associated with an increased risk of dry eye syndrome.

Tuna consumption was inversely associated with dry eye syndrome. Women who reported a minimum of five servings of tuna weekly had a 68% reduced risk of dry eye compared to women who consumed one or fewer servings of tuna per week.

The study authors noted some limitations in their study. “We could not differentiate between evaporative and aqueous-deficient subtypes of dry eye syndrome,” the authors said in the October issue of American Journal of Clinical Nutrition. Although the classification of dry eye syndrome “was certainly not perfect,” misclassification would tend to bias estimates toward the null, they said.

The study authors noted that their results are consistent with anecdotal clinical observations and other postulated biological mechanisms.

“To our knowledge, the is the first study of dietary intake of omega-3 or omega-6 fatty acids (or both) as it may relate to the prevention of dry eye syndrome,” the authors said. “In the current study, women with a higher intake of omega-3 fatty acids appear to have a lower risk of dry eye syndrome than do women with a lower intake.”