Dietary factors may protect against or reduce the risk of cancer. Other factors may increase the risk of cancer. Usually, diet is only one of several factors involved. Studies have shown that high intakes of fruit and vegetables may reduce the risk of many different cancers, eg lung cancer and also cancers of the digestive system, eg colon cancer. This may be because fruit and vegetables contain substances called antioxidants.
Antioxidants protect cells from damage.
Cell damage may start the process of a normal cell becoming a cancer cell. Also most fruits and vegetables are good sources of fibre which may reduce the risk of colon cancer. There are also others, for example, some of the substances that give fruit and vegetables their colour and flavour. Some vegetables contain vitamin E which is also an antioxidant. Good sources of vitamin E are nuts, seeds, some cereals and vegetable oils.