Eat a clean diet, and you'll also help fight cancer growth. Following a diet rich in processed foods puts you at an increased risk of cancer, explains the Colorado State University Extension, and saturated fat, processed meat and fried foods all up your cancer risk. On the other hand, a clean diet, rich in fruits and veggies, boosts your intake of phytonutrients and antioxidants, which fight cancer growth. Colorado State highlights cruciferous veggies -- a family that includes broccoli and kale -- and tomatoes as especially beneficial.