The importance of fatty-acid balance.

The importance of fatty-acid balance.

Whether or not eyes are mirrors of the soul, it appears that they can reflect your state of health. A new study indicates that the common condition dry eye, a sandy-gritty irritation or burning sensation that worsens as the day progresses, offers a telltale sign that the body is running low in omega-3 essential fatty acids.

In an overview of the diets of more than 32,000 women enrolled in the Nurses' Health Study at Harvard Medical School, women who ate two to four three-ounce servings of fatty fish weekly reduced their risk of dry eye by 18 percent. Women who ate five to six servings per week reduced their risk by 66 percent.

"The more omega-3 and fewer omega-6 fats that subjects ate, the lower their risk for dry eye," says ophthalmology researcher Jeffrey Gilbard. Omega-3 fatty acids are prevalent in fatty fish (salmon, sardines and herring) and flaxseed, while omega-6 fats come from sources like margarine and oils made from corn and soybeans.

Dry eye, which affects 59 million Americans and is the most frequent complaint patients bring to their eye doctors, occurs when a coating over the eye's surface called tear film loses some of its protection, causing inflammation in the tear glands. An oily layer in this film acts like a biological plastic wrap protecting the moist layer beneath. But when a person eats scant omega-3 fatty acids and too many omega-6 fats, it appears that the oily layer can't do its job as well, resulting in inflammation and the symptoms of dry eye. An overabundance of omega-6 fats can also produce inflammation in other areas of the body that increase risk for heart disease, stroke and dementia.

Gilbard, a self-proclaimed "junk food king" years ago, now eats salmon five days a week and sprinkles flaxseed oil on his salads. But, recognizing that many people won't eat this way, he says that some pharmaceutical grade omega-3 supplements can deliver the essential nutrients needed to prevent dry eye. Aim for 1,350 milligrams per day. He suggests that all adults increase their omega-3s as part of a healthful diet, "If not for their eyes, then for their hearts and brains."

-Robin Edelman, MS, RD, CDE