It has been well-established from many individual studies that being physically active reduces colon cancer risk.  That’s a big deal since about 100,000 Americans are diagnosed with colon cancer each year.

Scientists Washington University School of Medicine in St. Louis have compiled 52 different studies to quantify the possible extent of the risk reduction gained by being an active person compared to someone who is sedentary.  It turns out to be about 24%1.  A rough calculation is that if everyone in the U.S. became physically active, there would be about 24,000 fewer new cases of colon cancer each year.  Wow!

Now before you get off the couch and head out the door for a quick walk around the block (great!) realize that the levels of physical activity that yield this reduction are fairly significant.  While the study cited here was not able to quantify the amount of physical activity that is needed to attain this benefit, other studies have suggested that it may be close to five or six hours per week  of moderate-intensity activities (aka brisk walking).  That doesn’t mean you have to spend an hour a day trudging on a treadmill.  A thirty minute walk with the dog after dinner and three 10-minute walking breaks throughout the day can get you to this level.

Still, even if you can’t get to five to six hours of moderate activity a week (remember mowing, dancing, playing sports, golfing without a cart, and similar activities can count), doing some physical activity is better than doing none. 


1 Wolin KY, Yan Y, Colditz GA, and Lee IM.  Physical activity and colon cancer prevention: A meta-analysis.  British Journal of Cancer.  2009;100:611-616.