Junk food, long cited as the main culprit in Americans' expanding waistlines, may be bad for eyesight too, a new study suggests.
Overindulging in fat-filled snack foods may heighten the risk of developing advanced age-related macular degeneration, the leading cause of blindness and vision impairment in the United States for those over 55, researchers at the Massachusetts Eye and Ear Infirmary said in a new study.
The irreversible eye disease affects the central vision of about 10 million Americans, and those numbers are expected to grow as Baby Boomers hit their mid-50s.
"What's important about this study is that it shows for the first time a link between diet and this problem," ABCNEWS' Dr. Nancy Snyderman told Good Morning America. "Before this, smoking was the only identified risk factor for macular degeneration. What the study shows is that specific types of fats, especially the kinds used in processed snack foods, can increase your risk of age-related macular degeneration more than twofold."
Chips, Cookies, Even Nuts on the List
Vegetable, monounsaturated and polyunsaturated fats, along with linoleic acid are the type of fats that put junk food enthusiasts at a higher risk for the eye disease, according to the study, published in the August issue of the Archives of Ophthalmology.
The foods that contain these fats are highly processed, store-bought junk foods. Included in the study: margarine, chocolate, commercially prepared pie, cake, cookies, peanut butter, potato chips, french fries and nuts. The study's 349 subjects were between 55 and 80 years old and had advanced stages of age-related macular degeneration.
Fill up on Fish
While snack foods were found to have negative impacts on vision, fish was found to be beneficial.
The study found that diets high in omega-3 fatty acids, found primarily in albacore tuna and salmon, could lessen the risk for age-related macular degeneration, as long as fish eaters maintain a low intake of linoleic acid (found in processed food and margarine). A previous study also showed that dark green leafy vegetables have the same impact.
Based on the new study, the researchers recommend avoiding highly processed snack foods and consuming two or more weekly servings of fish high in omega-3 fatty acids.
Among those 75 and older, more than 25 percent have some signs of age-related macular degeneneration, and 6 percent to 8 percent have the advanced stages. It is incurable, and there is no proven treatment for the early and moderate forms of the disease. Those with later stage age-related macular degeneration have limited therapeutic options.
If your vision starts to change, especially if your central vision seems to have holes punched in it, go to a doctor immediately, Snyderman said.