Many constituents in our diet are chemopreventive agents in animal models. Experiments with cultured cells revealed various potential mechanisms of action . Epidemiological observations show lower cancer rates in people whose diets are rich in fruits and vegetables . This has led to the theory that diets rich in fruits and vegetables contain a high concentration of antioxidants which are thought to be chemopreventive.Evidence based studies have also revealed that many debilitating ailments such as alzheimers disease,schizophrenia etc show a remarkable increase in free radicals.It may then be conceived that addressing oxidative stress may be a prerequisite to preventing or even attenuating many degenerative diseases.Experiments in animal models have revealed that there is a positive corellation between the oxidative state of the body and degenerative diseases.