By Chris Woolston, M.S.
You've probably already heard that good nutrition and regular exercise can lower your risk of cancer. That's all well and good, but not all cancers respond the same way to lifestyle. Here's a closer look at the sometimes complicated relationship between, diet, exercise and 13 specific cancers from the American Cancer Society. Fortunately, many of the steps that protect you from one cancer will protect you from others as well.
Smoking is a major cause of bladder cancer, so one option for prevention is clear. There's some evidence that you can also lower your risk by eating plenty of vegetables and drinking lots of fluids.
As far as anyone can tell, diet and exercise don't have any effect on your risk for brain cancer.
There are never any guarantees when it comes to breast cancer, but you can lower your risk by drinking alcohol only in moderation (one drink a day for women), maintaining a healthy weight, and getting at least four hours of exercise each week. There's some not-especially-strong evidence that getting lots of fruits and vegetables will help, too.
Not surprisingly, there's a relatively strong link between your diet and your risk for colorectal cancer. Getting plenty of vegetables and fruit may lower the risk, while eating a lot of red meat may increase the risk. Calcium and vitamin D may help protect against colon cancer, so you want to get a good supply of those minerals. High levels of calcium may increase prostate cancer risk, though, so men may want to limit calcium intake to 1,500 mg per day.
Research suggests that moderate, regular physical activity may lower the risk of colorectal cancer (especially colon cancer), and vigorous activity may be even better.
Women who are overweight are at higher risk for endometrial cancer, partly because extra body fat can disrupt hormone levels. Maintaining a healthy weight through diet and exercise can lower a woman's risk. Limiting alcohol to one drink a day could help, too.
For reasons that aren't clear, overweight people are especially vulnerable to kidney cancer. The prevention message: Maintain a healthy weight, and you're less likely to get this disease.
Leukemias and Lymphomas
As with brain cancer, there's no sign that these cancers of the blood have anything to do with a persons diet or exercise habits.
Obviously, smoking is the main cause of lung cancer, and the best thing you can do to avoid the disease is stay away from tobacco in all of its forms. That said, people who get their full share of fruits and vegetables seem to have some extra protection against the disease.
There used to be hope that antioxidant supplements could prevent lung cancer, but that hope has faded. Large studies have found that, among smokers, high doses of vitamin A and beta-carotene supplements may actually slightly increase the risk of lung cancer. In short, it's probably better to get your antioxidants the natural way: with fruits and vegetables.
Oral and Esophageal cancers
Drinking too much alcohol can increase your risk of oral and esophageal cancers, especially if you're also a smoker. People who are overweight or who skimp on fruits and vegetables also seem to be at risk. Having just one or two drinks a day, maintaining a healthy weight, and eating plenty of produce will improve your odds.
It's unclear if diet has any effect on the risk of ovarian cancer. But to play it safe, stick to the basics: Drink only in moderation and get lots of fruits and vegetables.
As the organ that makes insulin, the pancreas is greatly affected by levels of sugar in the blood. Being overweight and staying physically inactive can mess up your sugar metabolism, and it can also increase your risk for pancreatic cancer. Eating lots of red meats and processed meats seems to amplify the risk, but fruits and vegetables offer protection.
Large amounts of dairy products and red meat can increase your risk of prostate cancer. On the plus side, there's some hope that natural antioxidants (such as lycopene in tomatoes) may help lower the risk, but the jury is still out. The best bet: Lots of fruits, lots of vegetables.
No surprises here: At least five servings of fruits and vegetables a day seems to lower the risk of stomach cancer. For extra protection, go easy on foods that are loaded with salt or nitrates (including processed meat, such as hot dogs).
American Cancer Society. Guidelines on nutrition and physical activity for cancer prevention. Guidelines for Cancer Prevention. 2008. http://www.cancer.org/acs/groups/cid/documents/webcontent/002577-pdf.pdf
American Cancer Society. The Complete Guide: Nutritional and Physical Activity. www.cancer.org/docroot/PED/content
Cleveland Clinic. Diet, nutrition, and healthy lifestyle help reduce cancer risk. 2010. http://my.clevelandclinic.org/disorders/cancer/hic_promoting_a_healthy_lifestyle_with_diet_and_nutrition_to_prevent_cancer.aspx