Walking lowers colon cancer risk in women

A team of researchers from Washington University in St. Louis and Harvard University has found that women who walk for at least two hours a week are less likely to get colon cancer than those who don't exercise regularly.

Women who walk for at least two hours a week are less likely to get colon cancer than those who don't exercise regularly, according to a recent study at the School of Medicine. Epidemiologist Kathleen Wolin discusses the findings.

The new finding builds on earlier evidence suggesting that physical activity decreases the risk of colon cancer in women. But the new study focused specifically on walking because that is the most common type of exercise women do.

"We looked at women who only participated in walking and found that walking was sufficient to reduce risk of colon cancer," says study co-author Kathleen Wolin, M.D., an assistant professor of surgery at Washington University School of Medicine in St. Louis. The study was published recently in the International Journal of Cancer.

Colon cancer is the third most common cancer in both men and women. The researchers analyzed information from the Women's Health Study to evaluate the benefits of walking. That study involves some 80,000 women ages 40 to 65, whose health is being monitored over many years' time.

Wolin says it's not yet clear how walking lowers colon cancer risk. It may reduce insulin resistance or alter hormone levels. Physical activity may also reduce inflammation throughout the body or reduce the time it takes for food, which may contain potential carcinogens, to pass through the intestines, she adds.