NEW YORK - People who lead an overall healthy life by exercising, eating right and not smoking have a significantly lower risk for age-related macular degeneration, a major cause of visual impairment in older adults, a study said.
Exercise and diet each reduced the risk, but both combined, along with a lack of smoking, caused the risk for age-related macular degeneration (AMD) to fall by more than 70%, said study author Julie Mares, at the University of Wisconsin in Madison.
"We don't need to be passive victims of these ravages of old age," Mares told Reuters Health.
"Relatively small things could make a difference in whether or not we develop AMD."
Macular degeneration results in a loss of vision in the center of the visual field due to damage to the retina and can make it difficult or impossible to read or recognize faces, although enough peripheral vision can remain to allow other daily life activities.
For the study,published in Archives of Opthalmology, Mares and her colleagues reviewed information about diet, exercise and smoking from 1,313 women between the ages of 55 and 74, collected during the 1990s.
The women were revisited on average six years later, at which point they received an eye exam to check for AMD.
Among the women who ate the healthiest, 11% had an early form of AMD compared to 19 percent of women who had the worst diets, after factoring in elements such as their intake of fruit, vegetables, whole grains, fat and sugar.
About one in 10 women in the highest quintile of exercise developed AMD, versus one in 5 of those who barely got any exercise.
When researchers combined the influence of diet, exercise and no smoking, the risk of AMD decreased even further, even though smoking alone was not related to AMD.
Though Mares and her colleagues looked at specific nutrients in relation to AMD risk, such as specific antioxidants, there was no significant difference compared to the lower risk as a result of an overall healthy diet.
For exercise, Mares said even 10 hours per week of light exercise, including housework, gardening and walking -- or 8 hours of moderate exercise a week lowered the AMD risk.
A healthy lifestyle might help lower the risk of AMD since diet and exercise lower blood pressure, which can protect the eyes from degeneration. Diet and exercise also reduce free radicals and are associated with lower levels of inflammation.
Mares suspects there would be a similar tendency in men.
"There's no reason I can think of to expect different results in men or women. However, these findings need to be confirmed in separate samples that include men," she added.