Cancer is a disease that is affecting most of the world; it is known to be a disease that doesn’t spare the poor neither the rich. Till to date the actual number and cause of the various types of cancers are unknown, as we all are aware of the common cancers such as breast, lung, cervical but are unaware of the rare subtypes such as rhabdomyosarcoma, Gorlin syndrome. Different kinds of drugs have been formulated to prevent the abnormal proliferation of cells, but as we know all drugs cause side-effects, so what would be the better option?
The nature around us has got the probable answers to all questions and in that way fruits and vegetables which grow naturally help in reducing the risk of various kinds of cancers. A healthy balanced diet with plenty of fibre, fruit and vegetables and less red and processed meat, salt can help cut cancer risk. ‘A healthier diets could help prevent one in ten cancers.’
Organo-sulphur compounds (isothiocyanates) that act by the following ways, they do not allow carcinogen activation, they work against the activated carcinogens, and they enhance elimination of carcinogens from the human body. The most common fruit having this constituent is papaya. The exposure of pancreatic, prostrate and leukemic cells to this fruit has lead to apoptosis, it also has anti-oxidant properties due to lycopene that induces cell death due to apoptosis, causes anti-proliferation in cancer cells, has anti-metastatic activity, and moreover causes the up regulation of cytoprotective enzymes.
Anti-oxidant properties seen with papaya is not only limited to it but is even noticed in various other fruits and vegetables such as those that are yellow and orange having high amount of carotenoids and bioflavonoids. These constituents are usually seen in pumpkin, carrot, pineapple, yellow peppers, oranges and peaches.
Not only papaya has the constituent of isothiocyanate but also vegetables that belong to the cruciferous family have high source of this constituent. These include broccoli, cauliflower, kale, cabbage, kohlrabi, rutabaga, Chinese cabbage, and radish.
Allium vegetables are another source of organo-sulphur compounds that is found in garlic, onions and leeks. Their main role is seen in the protection of stomach as well as colorectal cancers. They act by inhibiting formation of DNA adducts by modulating enzyme activity that affects the uncontrolled cell proliferation of cancer cells.
Anthocyanins is the most abounding constituent in fruits and vegetables, seen in red colored fruits and vegetables that include: strawberries, beets, red peppers, red onions, pomegranates and red grapes. The above mentioned fruits and vegetables are also known to have lycopene and thus shows enhanced anti-cancer activity. The anthocyanins act with the aid of inhibiting cell proliferation by blocking various stages of the cell cycle, causes apoptosis via both intrinsic and extrinsic pathways, inhibition of angiogenesis by blocking tumour necrosis factor alpha (TNF-a)-induced VEGF expression in epidermal keratinocytes.
Anti-oxidant properties seen with papaya is not only limited to it but is even noticed in various other fruits and vegetables such as those that are yellow and orange having high amount of carotenoids and bioflavonoids. These constituents are usually seen in pumpkin, carrot, pineapple, yellow peppers, oranges and peaches.
Thus as many drugs such as hydroxyurea, alkylating agents, mercaptopurine, thioguanine, 5-flurouracil, act on various sites on the cell cycle and cause inhibition of cell proliferation.
On the other hand, as chemotherapy is the ultimate treatment of cancer, it is usually advised to have a chemotherapeutic diet concurrently. Such as the latest drug Herceptin, a monoclonal antibody, which is used to treat HER2 positive breast cancer, a few drugs have shown to enhance its action and those include: green tea and olive oil which also have a supplementary effect of counteracting the Herceptin resistance.
Taxols are another class of anti-cancer agents (paclitaxel), of which a numerous amount of foods help to increase its cytotoxic effect on cancer cells, such foods include: apples, bell pepper, broccoli, cabbage, cauliflower, olives and olive oil.
When on Adriamycin (doxorubicin) some foods consumed cause synergistic effect and safely reduce side-effects, these include: apples, bell pepper, broccoli, cucumber, carrots, onions, lemons, tomatoes and watermelon.
Although to a lesser extent, food does help in the prevention of cancer and improve the quality of life, but this should be noted in the sense that all foods should be taken in limits, as increasing the content of certain foods may actually trigger the effect of cancer.
Therefore, the foods that are carcinogens should be identified and avoided, these include: microwave foods (as microwave rays are harmful to the body and also foods that need microwave activation contain perfluoroctanoic acid, that has shown to increase risk of testicular, kidney, liver cancer), processed meats, canned tomatoes, hydrogenated oils and refined sugar.
Improved food, better lifestyles and developments in the functional food industry are all essential to cancer prevention.
( Authors are with Manipal College of Pharmaceutical, Manipal, Karnataka)