The researchers came to this conclusion after they analysed survey data from 1,932 adults who answered questions about colon cancer risks and noticed that 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.
Study co-author Elliot Coups said that many factors contribute to the information gap amongst the patients.
"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," he said.
Coups said that 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.
"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. Going through each specific health benefit of physical activity would take considerable time," added Coups.
He also said that 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.
According to Edward Giovannucci, M.D., a professor at the Harvard School of Public Health, 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.
"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," he 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," said Giovannucci.
The study appears in the August issue of the journal Patient Education and Counseling.