The Eyes Have It

For the 8 million Americans diagnosed with age-related macular degeneration or those concerned about developing this degenerative eye disease, the leading cause of irreversible blindness, there's good news. New research has revealed that avoiding trans fats in the diet, along with other lifestyle factors, may lower the risk of the disease's onset and progression.

AMD starts with tiny yellow deposits called drusen, waste products from the retinal cells that accumulate under the retina. When the drusen increase in number and size, they harm light-sensitive cells in the macula (the small part of the retina responsible for sharp central vision), eventually disrupting sight and gradually leading to blindness. Researchers suspect that circulation is impeded in the blood vessels that supply the macular area.

Over a period of five years, a team led by epidemiologist Johanna M. Seddon at the Massachusetts Eye and Ear Infirmary (Harvard) studied the diets of 261 patients with at least some signs of AMD. The verdict: consuming more fat increased the risk of advanced disease, but the type of fat was important. "Higher intake of trans fats [commonly found in processed baked goods] increased the risk of progression by a factor of more than three," explained Seddon, "while a higher intake of fish and nuts (containing omega-3 fatty acids) was protective."

The findings didn't surprise Seddon, who has conducted a number of long-term studies on AMD development, each bringing the picture more into focus: "The same risk factors for developing heart disease seem to apply to the risk for progression of macular degeneration."

Because of the similarities, "the practical advice you hear for cardio health will likely benefit your eyes," Seddon says. "Choose a diet full of highly colored fruits and vegetables, especially dark green vegetables like spinach, kale, parsley and broccoli. These have carotenoids called lutein and zeaxanthin that have a potentially protective effect on the macula. Omega-3s, plentiful in fish and nuts, are found in the photoreceptor cells of the retina and our results suggest that these are beneficial. And of course quit smoking, increase exercise, watch your weight and control blood pressure."