It is a well researched fact that an unhealthy diet may contribute to developing cancer in the body. High fat diets have been associated with cancer of the uterus, the breasts, the prostate gland, and the colon. Regular intake of excessive calories is also associated with cancer of the gallbladder and the endometrium.
One of the first indications of cancer is unexplained weight loss. The tumour cells use the nutrients taken by the host for their own metabolism and development. This often results in loss of muscle tissue, and hypoalbuminaemia with anaemia. Due to decreased digestive secretions, cancer patients become satiated earlier than normal, thus contributing to further weight-loss.
Cancer treatments are designed to kill the cancerous cells, but this can also damage healthy cells, which can cause problems like loss of appetite, change in sense of taste and smell, constipation, diarrhoea (which may be caused by radiation therapy), bloating, cramps, dry mouth (which may be the result of chemotherapy and radiation therapy that often lead to dryness of the mouth), and lactose intolerance.
Other common side-effects are nausea, sore mouth, sore throat, having trouble in swallowing, weight gain, or weight loss.
Despite their need for a nutritious diet, anorexia is a major problem for cancer patient. It is particularly difficult to combat because patients tend to develop strong food aversions due to the effects of chemotherapy.
The calorie need will vary from one cancer patient to another. A diet of 45 to 50 kilocalorie per kilogram of body weight may be recommended. High carbohydrate and fat intake will be necessary to provide this energy.
Cancer usually causes an increase in the metabolic rate, and the nutrient lost to the cancerous cells must be replaced. Patients on high protein and high kilocalorie diet are more capable of withstanding the side effects of therapy and higher doses of drugs.
Patient with good nutritional status will need from 1 to 1.2 gram of protein per kilogram of body weight. Malnourished patients may need between 1.3 and 2.0 g of protein per kilogram body weight per day.
Vitamin and minerals are essential for metabolism and tissue maintenance. However, for cancer patients the dietary recommendation is to eliminate vitamin A and vitamin E in the form of supplements, as this may prevent cancer cells from self-destruction and work against cancer therapy. Fluids are deemed important to help the kidneys eliminate the metabolic waste and the toxins of the drugs.
Some general suggestions for patients
Several small meals are better than three large meals.
It is preferable to serve the nutritionally richer meal early in the day because the patient is less tired and may have a better appetite at that time.
Eat those foods that you can, even if it is only one or two times.
Do not worry if you cannot eat at all on some days. Start eating as soon as you feel like it.
Drink plenty of liquids. It is even more important to get plenty to drink on days when you cannot eat.
Special care should be given in the way you handle and prepare food.
Scrub all raw fruits and vegetables before you eat.
Sip only small amount of liquid during meal.
Have a large drink at least 30 minutes before or after meal.
Avoid food and drink with smell that bothers the patient.
Keep your mouth clean.
Drink warm and hot liquid, which can help relieve constipation.
Eat high fibre food, which include whole grain, beans, dried fruits, etc.
Eat foods and liquids that are high in sodium and potassium in case of diarrhoea.
Chew gums or ice cubes in case of a dry mouth.
For nausea, have foods and drink that are neither too hot nor too cold.
For sore mouth, drink with a straw.
Avoid certain foods like citrus fruits, spicy, salty or crunchy dishes, and drinks when your mouth is sore.
In case of sore mouth rinse your mouth 3 to 4 times a day.
In case of nausea do not have anything to eat or drink until your vomiting stops.
Eat when it is time to eat rather than wait to get hungry.
Preventive nutritional measures
A diet rich in fibre helps to protect against colorectal cancer. Vitamin C rich food may protect against the cancer of the stomach and the oesophagus. Vitamin A and carotene may protect against cancer of lung, bladder and larynx.
Fruits and vegetables have abundance of phytochemicals so it is advised to eat five or more servings of fruits and vegetables per day.
Legumes such as soybean, dried beans and lentils may also protect against cancer. High intakes of soy foods are associated with a decreased risk of breast and colon cancers. Carrots, tomato and other food rich in carotene and lycopene may reduce the risk of ovarian cancer.