Vegetables cannot be substituted with vitamins pills and other synthetic substances as scientists have found that fruits and vegetables are major source of phytochemicals and antioxidants that reduces the chances of cancer.
Phytochemicals are the chemicals of natural origin from plants. They are not the minerals or vitamins, not even nutrients and cannot be obtained from animals. In the recent time study shows the beneficial effect of phytoChemicals in protection from cancer. These also help in other diseases like heart diseases, adult diabetes etc.
Phytochemicals acts as blocking agent or suppressing agent that suppress the cancer causing factors, Carcinogens. Hence check for the growth of cancerous cells in the body. For example:
Cruciferous vegetables (cabbage, cauliflower) contain a phytochemical INDOLE that acts as suppressing agent by increasing the enzymes in colon that inactivates the carcinogens. Carcinogens interfere in normal functioning of body cells by acting as free radicals but the suppressing agents have checked this.
Some fruits and vegetables contain more potent cancer fighters than others. Crucifers for colon cancer, risk of lung cancer decreases considerably through high fruit and carrot intake. Risk of stomach cancer can be decreased through eating one or more onions every day. Studies suggest that soy foods diminish cancer risk in many areas, including breast, colon, rectum, lung, and stomach. The National Cancer Institute advocates a minimum of five servings of fruits and vegetables a day. Some people do not eat any at all. Phytochemicals benefit whether fruits or vegetables are raw, canned, frozen, juiced, or peeled. Pickling, boiling, microwave, baked or dried.