Vegetables, Fruits and Cancer Prevention

Abstract

Cancer chemoprevention is a new promising strategy for cancer prevention by the use of either synthetic or naturally occurring chemicals. At present, there are a large number of chemicals found to exhibit anticarcinogenic potentials in animals and several of them are under clinical trials.

The International Committee of World Cancer Research Fund/ American Institute for Cancer Research have evaluated the chemopreventive potentials of some factors in food from the published data and found that the relationship between the consumption of vegetables and fruits with the decreased risk of cancer can be divided into 3 groups: convincing, probable and possible. The first group includes the consumption of vegetables and fruits with the decreased risk of cancers of the mouth, pharynx, esophagus, lung and stomach, and that of vegetables with cancers of colon and rectum. The probable group includes the relationship between the consumption of vegetables with the decreased risk of cancers of larynx, spleen, breast and urinary bladder, while the possible group refers to that of vegetables and fruits with the decreased risk of cancers of cervix, ovary, uterus and thyroid, and that of vegetables with cancers of liver, prostate and kidney. It was further found that the risk of some cancers may be reduced by the consumption of various kinds of vegetables and fruits, for examples, cancers of the mouth and pharynx by all vegetables and fruits, carrots, green-leaf vegetables and citrus fruits; esophagus cancer by all vegetables, tomatoes and citrus fruits; lung cancer by vegetables and/or fruits, green-leaf vegetables, tomatoes and carrots; stomach cancer by green-yellow vegetables, tomatoes, cruciferous vegetables, allium vegetables, citus fruits and vegetables and/or fruits; colon and larynx cancers by all vegetables and fruits, and rectal cancer by cruciferous vegetables, carrots and citrus fruits.

At present, there are many studies investigating cancer chemopreventive agents and found vegetables and fruits contain various kinds of chemicals possessing chemopreventive potentials, but most of them are non-nutrients constituents. In this communication, we briefly review some cancer chemopreventive agents which received much attention and may have potentials to prevent cancer in humans, such as isothiocyanates, indole-3-carbinol, organosulfur compounds,  β-carotene, tea and epigallocatechin gallate, curcumin, lycopene, isoflavones, limonene and 1-perillyl alcohol.