3 of 14

Don't smoke

Most people know smoking causes lung cancer and heart attacks. But you can add colorectal cancer to the list.

Smokers are 18% more likely than nonsmokers to develop colorectal cancer, and 25% more likely to die from the disease, according to a 2008 study.

And a 2009analysis by the American Cancer Society found that people who had smoked for at least 40 years, or who didn't quit before they hit age 40, were 30% to 50% more likely to develop colon or rectal cancer than nonsmokers.

Next: Avoid red meat