Most Adults Don't Realize Activity Lowers Colon Cancer Risk

Ruzanna Harutyunyan's picture

Many experts now consider colon cancer a largely preventable disease, but a new study finds that primary care doctors might not always inform patients about one important step they can take to reduce their risk: becoming more physically active.

When researchers analyzed survey data from 1,932 adults who answered questions about colon cancer risks, only 15 percent listed physical activity as a means of reducing their risk.

Yet a sedentary lifestyle accounts for as many as 14 percent of all colon cancer cases in the United States. Highly active individuals have a 30 percent to 40 percent lower risk of developing colon cancer, according to the researchers.

Several factors contribute to the information gap, according to study co-author Elliot Coups. “Patients may not be learning this information from their health care providers and information regarding colon cancer prevention is not as well publicized as it could be.”

The study appears in the August issue of the journal Patient Education and Counseling.


Doctors might find it easier to promote the general benefits of exercise, without specifically mentioning colon cancer, even to a patient who has a family history or has other risk factors, said Coups, at the Division of Population Science at the Fox Chase Cancer Center in Cheltenham, Pa.

“In the context of busy clinic visits, it is in some ways efficient for patients to be reminded that physical activity is good for their health in general,” Coups added. “Going through each specific health benefit of physical activity would take considerable time.”

Doctors might also need to offer more information about what it means to be physically active, as patients could imagine it involves dramatic lifestyle alterations, he said.

There is a strong benefit in going from completely sedentary to some modest levels of activity, such as walking two to three hours a week or gardening, said Edward Giovannucci, M.D., a professor at the Harvard School of Public Health. “Sedentary people should first set such moderate, achievable goals. More benefits could accrue from higher levels and more intense exercise, such as jogging, running or tennis. To some extent, more may be better, but it is important to note that a little is much better than nothing.”

Because studies might skew toward cultural norms and 40 percent of Americans never engage in leisure time physical activity, inactivity could be a factor in over 14 percent of the estimated 112,000 cases of colon cancer diagnosed each year, Giovannucci said.

“While many people are vaguely aware that exercise is good, the idea that exercise specifically prevents a large proportion of a common cancer may make an impact on the patient,” he said.