By Amy Norton
NEW YORK, Aug 15 (Reuters Health) - Ulcers are most often caused by
infection with H. pylori bacteria, with lifestyle factors such as eating habits
and stress playing a lesser role. Now, researchers suggest that regular exercise
may counter all of these factors and reduce the risk for at least one type of
ulcer.
In a study of more than 11,000 men and women, investigators found that
active men had one-half to one-third the risk of developing a duodenal ulcer
over 20 years compared with their sedentary peers. Duodenal ulcers occur in the
upper part of the small intestine. The study results showed no link between
exercise and stomach ulcers.
Researchers led by Yiling Cheng of the University of South Carolina in
Columbia report their findings in the August issue of the Western Journal of
Medicine.
An erosion in the lining of the digestive tract, ulcers strike up to 5
million Americans each year. Long believed to be caused by poor diet or stress,
ulcers were definitively linked to H. pylori infection in the 1980s. Yet, since
H. pylori bacteria dwell within half the world's population, researchers also
believe that lifestyle factors help determine which people develop ulcers.
In the current study, exercise was one of those factors, at least for men.
Study co-author Dr. Caroline A. Macera of the Centers for Disease Control and
Prevention in Atlanta, Georgia, told Reuters Health that the study included too
few women to find a statistically significant effect of exercise in females.
Despite this, she said that "we think it is possible that physical activity
could be a good way to reduce the chances of getting ulcers."
Among men, those who walked or ran at least 10 miles a week were 62% less
likely than inactive subjects to develop an ulcer. Men who walked or ran less
than 10 miles each week had about half the ulcer risk of those with no regular
exercise. This link held after the researchers accounted for other factors such
as age, stress, smoking, body weight, and alcohol use.
It is unclear why exercise affected only duodenal ulcers in the study. "We
think the mechanisms of duodenal and gastric ulcers may differ," Macera said,
"and the other (risk) factors may be more important in the development of
gastric ulcers than physical activity."
Also unknown is how exercise might prevent ulcers. Macera speculated that
exercise may help the body deal with the physical effects of psychological
stress. On the other hand, she and her colleagues report, exercise may quash
acid production in the digestive tract, or enhance the immune system's ability
to fight off infection.
