Contributed by: Dr Grace Tan
General Surgeon and Surgical Oncologist
When you are fit, eating enough food to get the nutrients and calories you need is usually not a problem. But when you are diagnosed with cancer, this may be challenging to achieve especially if you are undergoing treatment, have side effects, or just don’t feel well. Eating well is important during this period, so that you can build up your strength, and tolerate the effects of your cancer and your treatments better.
Standard treatment for cancer includes surgery, chemotherapy, radiotherapy, and often a combination of the above.
Surgery is performed to remove the cancer, and often includes the removal of an organ or part of an organ. Surgery is often used together with radiation and/or chemotherapy. Prior to, and after surgery, your body needs more calories and protein for wound healing and recovery.
Radiotherapy uses radiation to kill cancer cells. The degree of side effects from radiation depends on the area and size of the area being radiated, the type and dose of radiation, and the number of treatments needed. Overall, radiation can result in a decrease in appetite, nausea and vomiting.
Chemotherapy uses drugs to target the cancer cells. The drugs can be taken by mouth or given through an injection. The drugs affect the cancer cells, but can also affect your bone marrow, hair and the lining of the stomach and intestines. This may cause patients to have difficulty swallowing, nausea, vomiting, diarrhoea and constipation.
In addition, cancer itself can also affect a patient’s eating habits. This may be due to changes caused by the cancer in a patient’s body, or due to the location of the cancer. For example, throat cancer can affect a patient’s swallowing, and as a result cause the patient to have a reduced appetite. Other common problems that cancer patients have include:
When the side effects of cancer or cancer treatment affect a patient’s food intake, changes can be made to help improve their nutrition. Eating foods that are high in calories, protein, vitamins, and minerals is beneficial. Here are some suggestions to help improve the nutrition of cancer patients:
1. Eat foods that are high in protein and calories. Examples of high-protein food include:
a. Beans, Chicken, Fish, Yogurt, Eggs, Tofu, Cheese.
b. Add extra protein and calories to food, such as using protein-enriched milk.
TIP: Eat high-protein foods first in your meal when your appetite is strongest!
2. Drink milkshakes, smoothies, juices, or soups if you do not feel like eating solid foods.
3. Eat small meals and healthy snacks often throughout the day.
a. Eat 5 or 6 small meals every day instead of 3 large meals.
4. Consider the use of dietary supplements, such as multivitamins. These may be helpful especially if patients are not able to get all their nutrients through food.
5. Be as active as possible so that you will have a good appetite.
Some cancer patients may try special diets i.e. vegan diet, macrobiotic diet, ketogenic diet. However, to our knowledge, for most of these special diets, there is no evidence that show that they are effective. Whilst this may be the case, there is often no harm trying these diets. However, maintaining sufficient calories may be difficult with some of the diets. Do discuss with your doctors if you plan to try any of these special diets.
In addition to special diets, patients have also enquired about nutritional supplements like Vitamin C and Probiotics.
Vitamin C may be helpful for patients undergoing treatment as it can help with wound and tissue healing, and help fight infections.
Probiotics are a mixture of microorganisms used as dietary supplements to help with digestion and bowel function. Some studies have shown that taking probiotics during radiation and chemotherapy can result in reduced side effects like diarrhoea, hence may be beneficial.
