Making simple lifestyle and diet changes can save your life. Here are 10 effective ways to decrease your chance of developing cancer.

By Michael Castleman

Steps 1-5

Making simple lifestyle and diet changes can save your life. As a health bonus, many of the same cancer-fighting actions also help fight heart disease, stroke, diabetes and other serious conditions. Here are 10 ways to decrease your chance of developing cancer.

1. Don't smoke, and avoid secondhand smoke. It's by far the biggest risk factor for developing lung cancer. While the proportion of Americans who smoke has dropped almost in half—from 42% to 23%—since 1965, 46.5 million still smoke. Tobacco use also increases the risk of mouth, tongue, throat and bladder cancers and accounts for 30% of cancer deaths a year.

If you smoke, ask your doctor for help quitting and urge family members who smoke to do the same. "Today there are more ways than ever before to help smokers quit," says Michael Thun, M.D., head of epidemiology research at the American Cancer Society in Atlanta. "Among them the drug Zyban and nicotine gum, patches and nasal spray." And if you don't smoke, avoid being in the presence of those who do. Secondhand smoke, or environmental tobacco smoke, also raises your risk of lung cancer. It causes 3,000 lung cancer deaths annually in nonsmokers, according to the ACS.

2. Control your weight. Health-conscious Americans know that being overweight boosts their risk of heart disease, high blood pressure, stroke, diabetes and arthritis. But many people don't realize that developing cancer is also linked to extra pounds. According to Dr. Thun, some of the cancers linked to excess weight include breast, uterine (endometrial), ovarian, colon, rectal, esophageal, kidney, gall bladder, liver, pancreatic, stomach and prostate, as well as the blood cancers leukemia, lymphoma and multiple myeloma.

Since 1982 American Cancer Society researchers have tracked the weight and cancer risk of 900,000 American adults. Their findings show that compared with people who maintained their recommended weight, those who were obese—as defined by having a body mass index of 40 or higher—were 57% more likely to die from cancer. "About 90,000 cancer deaths annually are associated with obesity," says Peter Greenwald, M.D., director of cancer prevention for the National Cancer Institute in Bethesda, Maryland.

3. Get physical. Exercise specifically reduces the risk of breast, colon and rectal cancer. It's not clear why exercise decreases breast cancer risk, which strikes 211,000 women a year and kills 40,000, but one reason may be that physical activity lowers the number of fat cells, which reduces levels of cancer-stimulating estrogen. "Colon and rectal cancers take a similarly huge health toll, with 150,000 new cases and 57,000 deaths a year," says Dr. Thun. It's also not exactly clear why exercise lowers the risk of colon and rectal cancers, but one theory is that it reduces constipation, which decreases the time carcinogens in stool are in contact with colon and rectal tissue.

"To get enough exercise to reduce your cancer risk, you don't have to join a gym," says Dr. Greenwald. "Just be more physically active every day. The intensity of exercise is not as important as its regularity. A brisk half-hour walk every day is enough."

4. Drink less alcohol. Having more than two alcoholic drinks a day for men, and one for women, increases the risk of many cancers including mouth, throat, larynx, esophageal, liver and breast. (One drink is defined as one 12-ounce beer, a cocktail containing 1.5 ounces of 80-proof liquor, or 5 ounces of wine, a standard wine glass about half full.)

However, modest alcohol consumption—up to two drinks a day for men and one drink a day for women—may reduce the risk of heart disease. "If you're at high risk for breast cancer, you shouldn't drink," says Dr. Thun. "However, if you're at low risk for breast cancer but at significant risk for heart disease, then a little alcohol may be beneficial. Your doctor can help you decide based on your health situation."

5. Take a daily multivitamin and mineral. Vitamins do not offer magical protection against cancer. They are not a substitute for a healthy diet of fruits and vegetables, and they don't eliminate the damage caused by a diet low in plant foods and high in saturated fats. "A multivitamin is an easy way to get some cancer-fighting antioxidant nutrients," says Sally Scroggs, R.D., senior health education coordinator of the Cancer Prevention Center at M.D. Anderson Cancer Center in Houston. Just don't overdose. Very high doses of many vitamins and minerals can cause problems. For example, vitamin B6 can cause nerve damage, and large doses of vitamin C and magnesium can cause diarrhea; worse, megadoses of vitamin D can be toxic. To be safe, stick to a multivitamin and follow the label instructions. In addition, if you smoke, steer clear of beta-carotene, a form of vitamin A, because it has been linked to an increased risk of lung cancer in smokers. Look for a multivitamin/mineral that contains selenium, an antioxidant mineral associated with a reduced risk of some cancers.

Steps 6-10

6. Drink green tea. Like fruits and vegetables, green tea is rich in antioxidants, and recent studies link it to a reduced risk of several cancers. For example, researchers at the University of Southern California in Los Angeles compared 501 Asian women who had breast cancer with 594 Asian women who didn't. The findings show that those with cancer drank significantly lower amounts of green tea. Other studies link green-tea drinking with a decreased risk of esophageal, pancreatic, colon and rectal cancers.

7. Reduce exposure to pesticides. Many studies have shown that farmers occupationally exposed to pesticides have unusually high rates of several cancers. Research suggests that suburban children may face a cancer risk from home and garden pesticides—everything from exterminator services to garden weed killers to the insecticide strips that hang on many porches. Researchers at the University of California at Berkeley compared household pesticide exposure in 324 infants and toddlers, half of whom were recently diagnosed with leukemia. The findings show that compared with the kids not exposed to home pesticide, those who were had up to three times the leukemia risk.

8. Avoid unnecessary X-rays. Radiation from X-rays increases the risk of several cancers. "Tell your dentist you don't want X-rays every year," advises Dr. Thun. "And if your child needs a CT scan, make sure the facility has low-dose pediatric CT equipment. But don't avoid recommended mammograms. The benefit of mammography for early detection of breast cancer far outweighs the risk of its radiation exposure."

9. Limit salted, pickled and smoked foods. These foods may increase your risk of stomach cancer. It's fine to eat an occasional dill pickle or a slice of smoked salmon, says Dr. Greenwald, but he advises against making salted, pickled or smoked foods a staple in your diet.

10. Rid your home of radon. Radon gas is the number-two (after smoking) cause of lung cancer, according to Dr. Thun, and is responsible for some 20,000 lung cancer deaths a year. You can't see or smell radon, a natural decay product of uranium that occurs in soil and rock. It accumulates in about six million U.S. homes, especially in basements. Most radon-related lung cancers could be prevented if Americans ventilated their homes more effectively. To learn if radon is a problem in your home, you can purchase a home-test kit available at many hardware and home improvement stores. If your home has high levels of radon, work with a licensed or certified contractor to improve ventilation.