More than 8 million people in the United States have a painful disorder called dry-eye syndrome, or keratitis sicca, according to Brigham and Women's Hospital. Most of these individuals are women. The condition involves either a decreased amount of tears, or the tears having an abnormal chemical composition making them less effective. Certain nutritional components are associated with a decreased and increased risk of dry-eye syndrome.
Symptoms
Dry-eye syndrome symptoms include pain, irritation, burning, gritty sensations and itchiness. The individual may experience blurred vision and sensitivity to light. The disorder can lead to discomfort and vision problems during reading, working on a computer, watching TV or driving. It can prevent people from wearing contact lenses as well.
Associated Factors
Dry-eye syndrome is associated with many factors. They include aging, allergies, autoimmune disorders, certain medications and surgery. The disorder is irritated by dusty and windy environments, as well as dry climates and dry indoor conditions caused by air conditioning or heating systems. Dry-eye syndrome is the most common complication of laser vision correction. Although nutritional deficiencies are not connected with dry-eye syndrome, some research points to diet changes possibly lowering the risk of dry-eye syndrome.
Tuna
High consumption of tuna is linked to a decreased risk of dry-eye syndrome. A study published in the October 2005 issue of the "American Journal of Clinical Nutrition" found that women who ate at least five servings per week of tuna had a 68 percent decreased risk of dry-eye syndrome when compared with women who consumed one serving per week.
Omega-3 Advantage
Tuna is rich in omega-3 fatty acids. Women with the largest amounts of omega-3 fatty acids in their diets decreased their risk of dry-eye syndrome by 20 percent, as shown by the journal study, when compared with women with the lowest levels of this fat in their diet. Omega-3 fatty acids at comparable or higher levels than tuna are found in walnuts, salmon, sardines, smelt, bluefish, swordfish, mackerel, scallops and crab. Fish with lower amounts of omega-3 fatty acids do not seem to protect against dry-eye syndrome.
Omega-6 Disadvantage
The study also found that a high ratio of omega-6 fatty acids to omega-3 fatty acids in the diet may elevate the risk of dry-eye syndrome. Omega-6 fatty acids are found in cooking and salad oils, and in animal meats. Brigham and Women's Hospital notes that the average American diet consists of a high ratio of omega-6 fatty acids to omega-3 fatty acids.
