By Mehmet C. Oz, M.D., F.A.C.S.

Some of the most exciting research about cancer relates to genetics—that is, finding what cancer you’re most prone to given your family history and makeup, and then adjusting your lifestyle to protect yourself against cancer. 

Helping Prevent Cancer: Stop Smoking, Diet, and Exercise

Sitting in the sun for long periods of time without sunscreen is the equivalent of sending an engraved invitation to cancer. And smoking?  There is such a direct correlation between smoking and cancer, you might as well be inhaling cancer cells.  Tobacco doesn’t just increase lung cancer, it also increases incidence of bladder, prostate, and breast cancers.  With other cancers, we don’t know their causes directly, but we do have some strong ideas about what can help prevent them.  Obesity and inactivity have been linked to cancer, so eating a reasonable, healthy calorie diet and maintaining good physical activity are prescriptions for keeping your whole body younger.

Cancer-Fighting Foods?

Some of the clearest evidence for cancer-fighting agents comes from nutrients and vitamins.  Vitamin D has been shown to decrease cancer risk in various studies, although we’re not exactly sure how it works.  We recommend getting 400 IU of vitamin D a day if you are 60 or younger and 600 IU if you’re over 60.  Folate or folic acid has been shown to decrease various cancer rates. The recommended amount of folic acid to reduce colon cancer, for example, is 800 micrograms daily.  Spinach, tomatoes and orange juice contain folates.  Be aware, however, that folate from food isn’t absorbed as well as folic acid from supplements.   The average intake of folate through food is 275 to 375 micrograms, so you would need a supplement of about 525 micrograms to make cancer less likely.

Studies have shown that tomatoes or tomato paste-containing foods reduce cancer risks. Some believe this is because of the active ingredient lycopene, known for its antioxidant properties.  Tomato products contain lots of lycopene, which is much more easily absorbed by your body when it is cooked.  Also, eating tomatoes with a little bit of olive oil, nuts or other fats (not pepperoni) help absorption.  So, eat 10 or more servings a week of lycopene-rich foods.

Cruciferous vegetables like broccoli, Brussels sprouts, cabbage, and cauliflower have a chemical in them that appears to help prevent the growth of some cancers.  It’s unclear how that chemical does its job, but studies of patients with bladder cancer and gut cancers indicate it’s likely that eating seven or more non-fried servings (handfuls) a week can prevent the growth of cancer by 50 percent.

Help Prevent Cancer with Vitamins and Supplements

Though there is still more research to be done, it appears that selenium supplements may help reduce incidences of cancer, in doses of 1000 micrograms or less a day.  We wish we knew how it works, but speculation is selenium helps power one of the body’s main sanitation systems that remove or detoxify harmful chemicals.

Another beneficial vitamin is vitamin C, in doses of 100 to 500 milligrams, twice a day. Vitamin C can give your immune system a major boost.  Think citrus fruits, berries, green veggies and tomatoes, or a vitamin C supplement in tablet or powder form if you can’t get enough in your diet.  To further reduce the risk of certain cancers, take 400 IU of vitamin E taken daily with vitamin C.  Find E in wheat germ, nuts, and vegetable oils, as well as in tablet form. Be sure to check with your healthcare professional about any multivitamins you want to take.

Live Healthier and Help Prevent Cancer

Supplements, nutrient-rich foods, exercise, avoiding obvious unhealthy behaviors such as smoking, and getting the recommended screenings and tests at various ages are all powerful ways to influence how well and how long you live.