ByElizabethLee WebMD the Magazine A bowl full of bright green steamed broccoli. You say either "Yum!" -- or "Where's the double cheeseburger?" But you know the broccoli is good for you, especially sans melted cheese. The question is, how good? And more to the point, can it -- or any food -- help prevent disease, such as cancer? The answer is yes -- some foods do show cancer-fighting properties, though no one is yet able to say one food or another can stop cancer in its tracks. Still, a body of research suggests an overall healthy diet filled with colorful fruits and vegetables is the key to skirting heart disease, diabetes, and possibly cancer, too. In fact, scientists know more about what not to eat -- processed meats, salty foods, sugary drinks, huge helpings of red meat -- than which fruits and vegetables to pile on your plate. But they do know those foods matter. A comprehensive review of thousands of studies on diet, physical activity, and weight con...