Many foods, especially fruits and vegetables, contain substances that help prevent the formation of cancers, or actively attack existing cancers. This seems to be one of the purposes of food, and is a part of the economy of nature. On the other hand, diets high in trans fat and sugar have been linked to a higher risk of colorectal cancer and other health problems. In the move from animal to vegetable fats, food manufacturers have found it necessary to hydrogenate vegetable oils in order to prevent them from going rancid. However, this process also results in the formation of trans fats, which are therefore present in most processed and fast food. Sugar is added to many foods to stimulate the taste buds, and make us want to eat more of that food.
For cancer prevention, a diet containing high quality fruits and vegetables, and low in processed and junk foods is essential. Ideally, fruit and vegetables should not only be free of herbicides, fungicides and pesticides etc., but should also be grown on soil that has not been depleted of natural minerals and nutrients. A number of experts have pointed out that for cancer treatment rather than prevention, it may be too late for a dietary regime alone to result in a cure. Concentrated extracts should also be considered. However, to maintain or regain health, the importance of a wholefood diet cannot be over-emphasized.