Men who are more sedentary face a higher risk of recurring colon polyps, according to a new study, even if these men break up their downtime with bouts of recreational activities such as walking, jogging or golf.
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This suggests that extended inactivity is itself a risk factor for noncancerous colon polyps, benign tumors that can give rise to colorectal cancer, the researchers said.
Known as "colorectal adenomas," these polyps typically can be removed after being identified during a colorectal cancer screening, such as a colonoscopy.
The recurrence of such polyps, however, seems to be greater among men (but not women) who are relatively less active. The researchers looked at activity levels among more than 1,700 men and women, and found that the more leisurely the men's lifestyle, the greater their risk for precancerous polyps.
Men who spent 11 or more hours a day in seated endeavors -- such as writing or reading -- were 45 percent more likely to develop polyps than those who spent less than seven hours a day engaged in sedentary behavior.
The study, funded by the U.S. National Institutes of Health and the U.S. National Cancer Institute, was schedule for presentation this week at the annual cancer-prevention conference of the American Association for Cancer Research, held in Oxon Hill, Md.
"Sedentary behavior is emerging as a risk factor for poor health," study author Christine Sardo Molmenti, a postdoctoral research fellow in the department of epidemiology at the Columbia University Mailman School of Public Health, said in a conference news release.
"Even among those who fulfill daily recommendations for physical activity, lengthy periods of sedentary behavior have been associated with early morbidity and mortality, leading to the 'active couch potato' paradigm," Sardo Molmenti said.
Although the study found an association between sedentary behavior and increased risk of colon polyps in men, it did not prove a cause-and-effect relationship. The authors said no protective link has been established between being more active and having a lower risk for colorectal cancer.
"Given the substantial increase in risk of [colon polyp] recurrence we observed for men with the highest sedentary time, we believe it would be beneficial to see 'reduce prolonged sitting time' added to the list of public-health recommendations currently in place for health promotion and disease prevention," Sardo Molmenti said.