Dry eye syndrome in women may be linked to their intake of dietary fat. But consuming foods rich in omega-3 -- such as tuna -- may reduce dry eye risk by 68 percent, according to a new U.S. study.

Dry eye syndrome, a painful and debilitating eye disease, affects more than millions of people globally, predominately women. The syndrome is characterized by a decline in the quality or quantity of tears that normally bathe the eyes to keep them moist. Symptoms of dry eye include pain, irritation, dryness and/or a sandy, gritty sensation.

Left untreated, dry eye can eventually result in scarring or ulceration of the cornea, and loss of vision.

In the study, researchers from Brigham and Women's Hospital (BWH) and the Schepens Eye Research Institute, both in Boston, analyzed data from surveys of more than 37,000 women enrolled in the BWH-based Women's Health Study.

"Our study set out to examine how changing dietary habits in America, primarily a shift in behavior of essential fatty acids we are consuming, may be associated with onset of this eye disease," study lead author Dr. Biljana Miljanovic, of the divisions of preventive medicine and aging at BWH, said in a prepared statement.

"We found that a high intake of omega 3 fatty acids, often referred to as a 'good' fat, commonly found in fish and walnuts, is associated with a protective effect. Conversely, a higher ratio of omega 6, a fat found in many cooking and salad oils and animal meats, compared to omega 3 in the diet, may increase the risk of dry eye syndrome," Miljanovic said.

Specifically, the study found:

• Women with the highest levels of dietary intake of omega 3 reduced their risk of dry eye syndrome by 20 percent, compared to 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. Currently, 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 to women who had one serving of tuna per week.
• Other kinds of fish that contain lower levels of omega 3 didn't seem to help protect against dry eye syndrome.

The study appears in the October issue of the American Journal of Clinical Nutrition.

More information

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