Age-Related Macular Degeneration: Couch Potatoes More at Risk?
People hoping to stave off the creakiness and sagging that come with age may have one more incentive to get off the couch. A new study suggests that exercise may protect against the most severe form of age-related macular degeneration, a disease that progressively damages the macula, the part of the eye involved with central vision.
Writing in the current British Journal of Ophthalmology, researchers from the University of Wisconsin report that regular exercise seems to work against the "wet" form of AMD, in which blood vessels grow abnormally in the eye and leak fluid, eventually causing vision loss. They monitored almost 4,000 people between the ages of 43 and 86 over a period of 15 years and discovered that those who engaged in regular physical activity at least three times a week, with or without sweating, were 70 percent less likely to develop the condition. The "dry" form of AMD, in which the retina thins and debris is trapped under the macula, is more common and less serious, though it can progress to the wet type. Physical activity had no effect on the incidence of dry AMD.
Though they might seem unrelated, AMD and cardiovascular disease share risk factors, including high blood pressure and cholesterol. Inflammation is suspected to play a role in both diseases, and exercise reduces inflammation in the body. So researchers wondered: Since exercise can ward off cardiovascular disease, could it do the same for AMD? The results are encouraging, although this observational study didn't rule out other factors that might be at work. So it's not conclusively proved that working out will prevent the disease, says Michael Knudtson, the biostatistician who coauthored the study.
But, he adds, it certainly won't hurt to exercise just in case.