It is no surprise that regular exercise can lower your risk of heart disease and diabetes, but did you know that it may prevent age-related eye disease as well?
Age-related macular degeneration is an eye disease affecting more than 10 million Americans, causing the gradual deterioration of the light-sensitive cells of the eye, often resulting in blindness. Macular degeneration is the leading cause of blindness for Americans over the age of 55.
However, exercise seems to protect the eye against macular degeneration for many of the same reasons it protects the heart against heart disease.
"Regular physical activity benefits health by reducing abdominal fat, weight, blood pressure and inflammation," wrote Dr. M.D. Knudtson and colleagues in the British Journal of Ophthalmology. "These factors have a role in the [development] of age-related macular degeneration."
To test this connection, over the course of 15 years, Knudtson looked at the rates of exercise and macular degeneration in almost 4,000 men and women between the ages of 43 and 86. Every five years, the participants were given an eye exam and asked about their general physical activity, including how many stairs they climbed, how many blocks they walked and how often they exercised long enough to break a sweat.
The researchers found that 25 percent of the study participants had an active lifestyle, and this population had a 70 percent lower risk of developing macular degeneration than the rest of the population. Even those who tended to walk more regularly than the rest of the study participants had lowered their risk of macular degeneration by 30 percent.
The researchers caution, however, that diet may also play a role in preventing this disease. But physically active people tend of be biologically younger than their sedentary counterparts, which would mean they tend to age slower, also helping to stave off this disease.
"Regular physical activity, such as walking, may have a protective effect against age-related macular degeneration," the authors conclude.