Cancer patients often require a combination of surgery, chemotherapy, radiation and hormone therapy to control their conditions. In the process, some healthy cells will be damaged, giving rise to side effects. However, these adverse effects can be controlled, with most alleviated. With proper diet and nutrition, patients can feel better, stronger and be more able to withstand treatment.

How to manage eating problems caused by these treatments
Surgery
After surgery, many patients need extra nutrition for their wounds to heal. But a person's ability to use nutrients may be changed by the surgical removal of a certain part of the oesophagus, stomach, small intestines, colon or rectum. In such instances, low-fat and easily digestible food and beverages are better tolerated. To prevent dehydration, take plenty of water or clear-soup extracts.

Radiation therapy
Nutrition-related side effects from radiotherapy usually appear in the second or third week of treatment and peak about two-thirds way into the treatment period. Try taking small, frequent meals through out the day and nutritional supplements like liquid-meal replacements.

Chemotherapy
Chemotherapy destroys cancerous cells but also damages healthy cells. Bone marrow, hair follicles and the cells lining the digestive tract from mouth to anus are susceptible to damage, resulting in mouth ulcers and diarrhoea, affecting food intake and absorption. To reduce exposure to possible infection-causing organisms, eat hygienically-prepared, weir cooked food.

Avoid the following:
• Raw and undercookod meat;
• Mouldy or unwashed vegetables and fruits;
• All miso products;
• Cold smoked fish;
• Aged cheese and cheese products that require refrigeration (for example, blue cheese and
  Mexican hot choose);
• Unpasteurised milk or yoghurt; and
• Raw, uncooked brewer's yeast.

How to handle specific side effects of treatment
Change in taste and smell
• Try food and drinks that are different from what is usually consumed.
• Mouth-rinsing and tooth-brushing can help to improve the taste of food.
• Use plastic utensils during meals if you develop a metallic after-taste.
• Take a lemon or mint flavoured sweet after eating to remove any unpleasant taste.
• Flavour food with onion, garlic, tumeric and spices.
• Eat room-temperature or cold food, which tends to be less distinct in taste and smell.

Poor appetite
• Eat small, frequent meals - every one to two hours.
• Consume food high in protein and calories, including hard-boiled eggs, nut spreads
  (cashew, almond or walnut), cheese, ice-cream, granola and cereal bars as well as
  sources of plant proteins (beans, legumes, nuts and seed).
• Sprinkle nuts and seeds on vegetables, salads and pasta, or on desserts like fruit, ice
  cream, pudding and custard.

Constipation
(Caused by pain-relief medication, change in eating habits and decreased physical
activity.)
• Eat at regular times and increase your activity level.
• Consume high-fibre food to stimulate bowel movement, including wholemeal rice, whole-
  grain breads and cereals, fruits and vegetables, dried fruits, seeds and nuts.
• Drink eight to 10 cups of liquid each day.
• Include hot  beverage and  high-fibre foods in your breakfast.
• Limit food and drinks that give rise to gas (for example, soil drinks, broccoli, cabbage,
  cauliflower, cucumbers, dried beans, peas and onions).

Diarrhoea
• Limit milk or milk products to two cups a day.
• Drink plenty of liquids or clear soups at room temperature.
• Avoid high-fibre food (nuts, seeds, whole grains, raw fruits and vegetables), high-fat
  food of the fried and greasy variety, food and drinks that give rise to gas, and spicy or very
  sweet food.

Nausea and vomiting
• Take plenty of fluids to prevent dehydration.
• Sip water, juices and clear, calorie-containing liquids or soups throughout the day.
  Cool liquids are better tolerated than very hot or icy fluids.
• Once vomiting stops,  eat easily digestible foods such as soups, crackers, gelatin and plain
  toast.
• Take six to eight small meals instead of three large meals a day.
• Avoid overly sweet, fried, oily and spicy food.

Sore or irritated mouth or throat
(Caused by chemotherapy and radiotherapy.)
• Eat soft, bland, lukewarm or cooled food.
• Eat food high in protein and calories to speed healing.
• Puree or liquefy food for ease of swallowing.
• Rinse mouth regularly with a mixture of baking soda (one teaspoonful) and plain or saltwater
  (240ml), to prevent infection and improve healing of sore mouth or throat.
• Avoid the following:
- Caffeine, alcohol and tobacco;
- Acidic or salty food and drinks and juices of citrus fruits like grapefruit, lemon, orange and
  lime;
- Pickled and vinegary foods;
- Tomato-based food;
- Dried toast, granola, raw fruits and vegetables; and
- Spices such as chilli powder, clover, curry, nutmeg and pepper.

Dry mouth or thick saliva
• Drink about eight to 10 cups of liquid throughout the day.
• Eat soft, moist food cooled to room temperature such as pureed fruits and vegetables and
  soft-cooked chicken and fish with broth, soup, sauces and gravy.
• Rinse mouth regularly with a mixture of baking soda (one teaspoonful) and plain or saltwater
  (240ml), which help maintains cleanliness and prevents infection.
• Avoid drinks containing caffeine (tea, coffee, cola and chocolate), as well as alcoholic and
  acidic beverages and even commercial mouthwash, as these can dry and further irritate the
  mouth.

NCCS is an institution of SingHealth, the largest healthcare group in Singapore.
For more information, visit SingHealth at http://www.singhealth.com.

Writen by: Chang Yok Ying, Principal Pharmacist, National Cancer Centre Singapore (NCCS)
This article first appeared in The Graduate magazine, a National University of Singapore Society (NUSS) publication