Here is a Hippocratic principle that states: “Let your medicine be your food and your food be your medicine.” In other words, eating right will keep your body in good condition. Cancer patients find it even more important to eat right – during treatment, their dietary intake can literally become a matter of life and death.

Surgery, radiation therapy, and chemotherapy are the most common treatments designed to stop the spread of cancer by killing and/or removing cancerous cells. Unfortunately, in the process of radiation therapy and chemotherapy, many of the body’s healthy cells are also damaged or destroyed.

During these treatments the body is working unusually hard: fighting the cancer cells, and attending to the damage to healthy cells caused by the therapy by repairing and replacing already-damaged cells. The strain of these combined tasks is considerable, and the body requires a proportionally higher amount of nutrients just to maintain standard body functions. Those same nutrients are also needed as building blocks for the functions that will repair all the collateral cellular damage caused by therapy which may be distant from the actual site of treatment. If there aren’t enough nutrients to go around, this will lead to malnutrition, a condition where the body is not taking in enough of the right kind of nutrients, forcing it to take them from stores in the fat or actually breaking down existing lean body mass (muscle tissue) to obtain what is needed.

Malnutrition is very dangerous — many studies have shown that weight loss drastically increases the mortality rate for most types of cancer while also lowering the response to chemotherapy. Of course, the reverse also seems to be true – in fact, a diet rich in the proper nutrients can often lessen the side effects of treatment and may even shorten recovery time. In most cases, malnutrition can be prevented by simply eating enough foods rich in vitamins and anti-oxidants. This includes plenty of fruits and vegetables (at least 5 servings a day), whole grain breads and cereals, lean cuts of meat (chicken, turkey or fish), and low-fat dairy products. For patients with oral cancer, eating properly can pose a difficult problem.

The proper nutrients assist the body in rebuilding damaged cells, but anti-oxidants may actually fight the cancer directly. An article published last year in the International Journal of Integrative Medicine states that an increase in survival has been demonstrated for patients who received Vitamin A or other anti-oxidants in combination with chemotherapy or radiation therapy. This finding was observed for patients with oral and several other kinds of cancer. Patients who were given beta-carotene and other anti-oxidants while undergoing surgery, chemotherapy, and radiation lived longer, with an increase in disease-free intervals.

What not to eat is nearly as important. Cutting back on salt, fat, alcohol
and sugar intake is essential. Not only are these “empty calories”, but in some cases they may assist the continuing development of cancer in the body. For instance, researchers now feel that some tumors are primarily obligate glucose metabolizers; in other words, these tumors are “sugar feeders”. In one animal study,
there was even a clear dose-dependent response, the more sugar
in
the diet, the quicker the cancer metastasized in the test animals.

Eating the right foods and avoiding the wrong ones may be difficult to adjust to at times, but it is certainly possible. Unfortunately, the nutrition battle often doesn’t stop there. The very side effects of the treatment that make a proper diet essential can often interfere with the act of eating itself, particularly for those with oral cancers. Since the healthy cells suffering damage include those in the mouth or digestive tract, an oral cancer patient can develop serious eating problems such as loss of appetite, nausea, vomiting, diarrhea, constipation, blistered mouth or throat tissues (mucositis), dry mouth (xerostomia), changes in taste, and fatigue. For those who suffer these side effects, eating the proper foods is difficult if not impossible; and as a cancer patient’s survival can be dependent on how he or she takes care of their body during treatment, these considerations must be addressed.

Those experiencing nausea or loss of appetite should press themselves to eat small frequent meals. Another method is to time meals to coincide with periods during the day when the patient is feeling best (generally, patients tend to feel better and have improved appetites early in the day with a progressive decrease in appetite as the day progresses.) Avoid strong aromas if they contribute to the feeling of nausea, such as serving cold rather than hot foods, since odors come from the rising steam. Also, here’s a medical excuse to order out! Food ordered from outside (so that preparation odors are not detected) will often be more tolerable if consumed immediately after arrival.

For those with changes in taste, dieticians have developed many different suggestions to make meals more palatable. Always rinse your mouth before eating. Serve meats chilled rather than hot, and try to substitute poultry, fish, eggs, and cheese for red meat. Another substitute for red meat: milk shakes, puddings, ice cream, cheese, and other high-protein foods. Lemon-flavored drinks will stimulate saliva and taste, but avoid artificial lemon and use sweeteners sparingly.

As radiation treatments produce mucositis, it may not be possible to tolerate acidic foods or strongly spiced foods, as treatment progresses. Finally, use disposable plastic utensils if patient experiences unpleasant metallic tastes while eating.

Dry mouth sufferers can eat soft or moist foods, (process foods in a blender if applicable). Creams, gravies, or oils can “lubricate” foods to make them easier to eat. Poaching fish in broth yields a tasteful and moisture rich food vs. cooking it by other methods that may be difficult to swallow. It may also help to avoid excessively hot or cold foods, or foods that adhere to the roof of the mouth. Take small bites and chew thoroughly.

Nearly all chemotherapy patients should drink more fluids in general and especially after certain chemotherapy treatments, but for those with a sore or blistered mouth or throat, fluids can become absolutely essential. Water, juice, soups, ice cream, ice pops, tea, milk, and gelatin are all suitable fluids. If your doctor has not restricted your fluid intake, try to drink at least six 8-ounce glasses of fluids a day. It may be easier to sip fluids frequently throughout the day as opposed to drinking full servings all at once. Many patients find that drinking nutritional supplements (such as Ensure ®, Resource ®, Boost ® ), or instant breakfast drinks add the essential vitamins and protein when the actual act of swallowing may be too discomforting. We recommend that oral cancer patients try making their own shakes in a blender. The combination of fresh fruits and protein powder derived from soy or whey, with yogurt, milk, or fruit juices, can make the difference when the actual act of eating or chewing is too painful. For those on a feeding tube, the blender drinks will be their first transition to real food, and an important step in regaining a sense of normality to eating.

Cancer patients may also consider nutritional supplements, especially for the times when they feel they cannot eat enough. Although certain nutrient supplements may not work as well as whole foods, there is a general feeling that taking recommended doses of certain vitamins can assist the process in most cases. Many of these are available in liquid or powder form which can be incorporated into a blender drink. Consult your doctor or dietician for more information.

No matter what the symptoms of the treatment, a person with cancer should try to maintain a positive attitude toward maintaining their diet. A change in one’s diet “because the doctor told me to” is the easiest and least helpful attitude, while eating better “because I want to do everything I can to beat this thing” is much more productive. After all, any cancer patient who tries to keep a good diet is contributing to his or her treatment as much as the medical professional. This is one area in which the patient can feel some sense of control and involvement; two things that many feel are lost during the treatment process. Also, keeping a good nutritional state can help people with cancer feel and look better and can help them maintain the physical strength to optimize day-to-day life. Because, in the end, this battle is fought day-to-day, and the best assistance the patient can provide is good nutrition and a positive attitude.

More on alternative feeding methods such as PEG tube feeding systems

This report discusses both the scientific evidence and the important practical issues that should be considered in making informed choices about nutrition and physical activity.