Vegetables and the fiber they contain have long been seen as a good source of phyto-chemicals and compounds that have cancer prevention properties. Colored cabbages are considered to be the best sources of such cancer-fighting compounds and should be eaten abundantly. Eating them raw increases the amount of cancer-fighting agents as opposed to cooked dishes. This is one study that shows naturally occurring compounds present in foodstuff that need no further synthesis as a potent cancer-risk lowering measure. So eat your green leafy vegetables. Other vegetables have shown potency in the fight to prevent cancer rather than treat it which involves costly and painful procedures. High-fiber diets have also shown promise in lowering the occurrence of colorectal cancers which gives credence to the old folk’s saying that all natural is best.