Exercise Might Reduce the Risk of Colon Cancer and Polyps
According to a report published in the British Journal of Cancer, exercise might reduce the risk for colon cancer and polyps. The authors looked at 20 clinical trials that reported on physical activity in individuals who underwent colon evaluation with sigmoidoscopy or colonoscopy. In all, more than 250,000 individuals were included.
This new study, based on a meta-analysis of 20 studies, focused on colon adenomas, the precancerous polyps that are removed during sigmoidoscopy or colonoscopy. The researchers found that regular physical exercise was associated with a 16% decrease in the risk of developing colon polyps, and with a 30% decrease in the risk of developing polyps that were large or advanced, and thus more likely to become cancerous. Exercise has many benefits that may lead to this finding, including boosting the immune system, decreasing inflammation in the bowel, and helping to reduce insulin levels — all factors that we know are likely to have an effect on bowel polyp risk.
Although some risk factors for colon cancer cannot be controlled, such as age, gender and family history, alterations in lifestyle can have a significant impact on colon cancer risk. The American Cancer Society (ACS) recommends at least 30 minutes of at least moderate activity on 5 days or more per week, and says that 45 to 60 minutes of intentional physical activity is preferable. The protective effect of exercise on colon cancer risk is "one of the most consistently reported relationships," according to a recent ACS report.
