Q: Are there any foods that increase the risk of cancer which we should avoid or eat less of in order to prevent the disease or during treatment of the same'

RS, Calcutta

From the nutritional standpoint, cancer can be viewed as a result of years of nutritional deficiencies and imbalances combined with pollution of the body cells with toxins and poisons. This ultimately leads to a damaged immune system, which is unable to check cell mutation, and surfaces as cancer. Food items that add to this toxic overload of the body would therefore have the potential of causing cancer. Let’s take a look at some of the common foods that increase the risk of cancer:

Trans fatty acids (TFAs) adversely affect the activity of the liver enzyme system concerned with the metabolism and elimination of carcinogens and other toxins from the body. TFAs are found in margarine, vanaspati and all hydrogenated or partially-hydrogenated vegetable oils. These commercial fats are mostly used in bakery products (breads, biscuits, cakes, etc.), all processed and restaurant foods.

The omega-6 poly-unsaturated (PUFA) vegetable oils are beneficial to our body only when they are used in their natural form, i.e. unrefined and unheated. Consumed in small quantities along with omega-3 fats, they actually protect us from cancer. However, the omega-6 PUFA oils should not be heated as they oxidise into compounds that increase the risk of cancer. Omega-6 PUFA fats are found in sunflower, safflower (kardi), corn, sesame, cottonseed and soyabean oils. Avoid cooking in these oils. Mono-unsaturated (MUFA) oils like unrefined mustard or extra-virgin olive oils are recommended.

When a food is fried or deep-fried, especially in omega-6 PUFA oils, the fatty acids in these are damaged by the effect of heat and oxygen. Chemical processes called cyclisation and polymerisation lead to the production of new altered molecules. These molecules impair cell respiration and inhibit the immune system and other cell functions. The least cancer-causing frying fats include butter, clarified butter (ghee), coconut and palm oils, groundnut and olive oils (in that order of preference) but only when used sparingly. Avoid eating fried foods in restaurants and fast-food joints.

During grilling, roasting or barbecuing, meat can get burnt. This leads to the production of carcinogens in the charred portions. On the other hand, sausages, salami and bacon are preserved with the use of nitrites and nitrates that can react with amines present in foods. This reaction leads to the formation of nitrosamines ' chemicals that have been linked to stomach cancer.

Peanuts as well as peanut butter and oil contain traces of aflatoxin ' a chemical produced by a mould that grows on peanuts. It is a powerful carcinogen.