Dry eye syndrome in women may be caused by a dietary deficiency of Omega-3sessential fatty acids usually provided in the diet by fish such as tuna or salmon, according to a new U.S. study.
Consuming sufficient Omega-3s may reduce dry eye risk by 68 percent. The study analyzed data from surveys collected from more than 37,000 women enrolled in the Brigham and Womens Hospital-based Womens Health Study.
Dry eye syndrome is a chronic and uncomfortable eye disease that affects more than 8 million people in the United States. Women are affected twice as frequently as men. The syndrome is caused by a decrease in tear production or increase in tear evaporation that makes the tears too salty. Symptoms of dry eye include dryness, burning and/or a sandy, gritty sensation.
Left untreated, dry eye may result in decreased vision, and be complicated by ulceration and scarring.
Our study examined the relationship between Omega-3 and Omega-6 consumption and the risk of dry eye, said study co-author Jeffrey P. Gilbard, M.D., of the Department of Ophthalmology, Harvard Medical School. Tuna is the major source of Omega-3 in the American diet. Vegetable oils are the major sources of Omega-6.
Women with the highest levels of dietary intake of Omega-3 reduced their risk of dry eye syndrome by 20 percent, compared with women with the lowest levels of Omega-3 in their diets.
A dietary ratio of Omega-6 to Omega-3 greater than 15:1 was associated with a 2.5 times increased risk of dry eye syndrome. The average American diet has a similar ratio of Omega-6 to Omega-3, the study noted.
Women who reported having at least five servings of tuna per week were at a 68 percent reduced risk of dry eye syndrome, compared with women who had one serving of tuna per week.
Other kinds of fish that contain lower levels of Omega-3 didnt seem to help protect against dry eye syndrome.
Given the warnings by the FDA regarding mercury and tuna fish, we dont recommend dry eye patients eat tuna five or more times per week, said Dr. Gilbard. Salmon and anchovies are very low in mercury, and would be a better choice.
For those of his patients who find this difficult or impossible, Dr. Gilbard recommends TheraTears Nutrition, a purified Omega-3 supplement designed for patients with dry eye.
The study appeared in the October issue of the American Journal of Clinical Nutrition.
From the June 21-27, 2006, issue