A study of the dietary intake and ratio of Omega-3 to Omega-6 fatty acids in the diets of 1,546 women reporting DES were compared to the ratios of these fatty acids in the diets of women without DES.
The information was taken from 39,876 women who participated in the Women's Health Study.
The source of the Omega-3 in the diet was mainly from seafood that contains the long chain EPA and DHA fatty acids. The Omega-6 source was mostly linoleic acid from margarine, butter and nuts.
Upon comparison of the dietary intake ratios of the Omega-6 to Omega-3s, researchers concluded that a higher intake of Omega-3 was associated with a decreased risk of incidence of DES, while a higher ratio of Omega-6 to Omega-3 was associated with an increased DES risk.
Miljanovic, Trivedi, et al ; "Relation between dietary n-3 and n-6 fatty acids and clinically diagnosed dry eye syndrome in women" AM J Clin Nutr 2005;82:887-93. http://www.ajcn.org/