Dark, leafy vegetables

According to the American Institute for Cancer Research: " Spinach, kale, romaine lettuce, leaf lettuce, mustard greens, collard greens, chicory and Swiss chard are excellent sources of fiber, folate and a wide range of carotenoids such as lutein and zeaxanthin, along with saponins and flavonoids. According to AICR's second expert report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective, foods containing carotenoids probably protect against cancers of the mouth, pharynx and larynx. Researchers believe that carotenoids seem to prevent cancer by acting as antioxidants - that is, scouring potentially dangerous "free radicals" from the body before they can do harm. Some laboratory research has found that the carotenoids in dark green leafy vegetables can inhibit the growth of certain types of breast cancer cells, skin cancer cells, lung cancer and stomach cancer. The Second Expert Report also noted probable evidence that foods containing folate decrease risk of pancreatic cancer and that foods containing dietary fiber probably reduce one's chances of developing colorectal cancer."