Dr. Oz says you can significantly reduce your chances of getting cancer by eating foods rich in folate—you should get about 800 mg a day. If you don't take it as a supplement, you can find folate in orange juice, spinach and other leafy green vegetables.

"Folate decreases arterial aging, decreases blood pressure and decreases cancer rate," Dr. Roizen says. On labels, look for the words "folate" or "folic," he says.