Exercise regularly.

Cancer prevention requires a strong immune system, and your immune system gets a boost from regular physical activity. Studies have shown that moderate levels of exercise can reduce the risk of colon cancer by 50 percent and the risk of breast cancer among postmenopausal women by at least 20 percent. Regular exercise has also been strongly associated with lower rates of lung and endometrial cancers. I recommend working some form of activity into your schedule — for 30 to 60 minutes per day, at least five days a week.