Nutrition plays an important role in the prevention and treatment of cancer. Eating the right kinds of foods before, during and after treatment can help in tolerating treatment better as well as facilitate recovery. Eating a healthy diet can also help maintain energy, strength and quality of life as you go through treatment.
After cancer is diagnosed, a treatment plan will be determined which may include surgery, chemotherapy, radiation, hormone or biologic immunotherapy or some combination of these treatments. All these therapies can affect both cancer and healthy cells. While it is important to help your body kill the cancer cells, it is also critical to promote the growth and/or repair of healthy cells. Many of the therapies used for the treatment of cancer may result in side effects which can cause lose of appetite, early satiety, sore mouth and throat, dry mouth, nausea and vomiting, diarrhea, constipation, weight loss, weight gain, and/or changes in taste and smell, all which can affect your ability to eat a good diet. Preventing or minimizing these side effects is important in order to prevent or minimize deterioration in your nutritional status which in turn can effect treatment and survival.
Not everyone experiences these side-effects, but the good news is that for those who do, many of the side-effects related to cancer therapies can be easily treated. Furthermore, many of these side effects generally go away after treatment is completed.
Following are nutrition recommendations for many of the side effects usually experienced during treatment. Some of these suggestions might be confusing since some of the recommendations might be dramatically different from the nutrition suggestions that are usually recommended. Because it is extremely important to maintain weight and strength throughout therapy, sometimes in order to accomplish this, it might be important to eat foods high in calories, fat, and protein. These suggestions might include eating more cheese, eggs, butter/margarine, or using nutrition supplements. Consuming a healthy diet that provides lots of fruits, vegetables, and whole grains is always recommended too.
- Loss of Appetite or Poor Appetite
- Early Satiety
- Sore Mouth or Throat (also known as mucositis and esophagitis)
- Dry Mouth
- Nausea & Vomiting
- Weight Loss
- Weight Gain
- Taste or Smell Changes
Poor appetite, or loss of appetite, is one of the most common side effects of cancer and/or its treatments. Although the precise reason for this is unknown, a number of reasons have been cited including the cancer itself, treatment or a combination both. The stress and emotions relating to the uncertainty surrounding the diagnosis of cancer can also suppress appetite. Additionally, some of the side effects associated with treatment such as nausea, vomiting, changes in smell and taste, and diarrhea can cause a decreased interest in eating.
Because many of the side effects related to cancer and it's treatments can lead to weight loss, it is important to discuss these issues with your physician as soon as they arise. Weight loss is associated with a decrease in immune function, energy, strength and an overall quality of life. Therefore, it is important to try and maintenance or minimize weight loss throughout therapy as much as possible. Following are some suggestions that may help:
- Eat small frequent meals throughout the day
- Snack on high calorie foods such as cheese, peanut butter, nuts, trail mix, ice cream, smoothies, milkshakes and pudding.
- Try liquid meal replacement supplements such as Boost®, Instant Breakfast® or Ensure®. Add protein powders to soups, smoothies, milkshakes and puddings.
- Add cheese, sauces, gravies, butter/margarine, mayonnaise, etc. to foods to increase calories.
- Take advantage of times when appetite is the best. Appetite is usually the best in the morning.
- Avoid filling up on liquids during meals. Drinking liquids a half hour before or after meal time may result in an increased consumption of food.
- Exercise daily if possible as exercise frequently increases not only appetite but also energy.
Early satiety is the feeling of being full too early after eating only a small amount of food. This can occur due to the treatment for cancer or because of the disease itself. Early satiety can result in the inadequate consumption of calories, protein, vitamins, and minerals that can then lead to weight loss. Focusing on eating foods that are higher in calories and protein (see the suggestions listed under the section about poor appetite) can help. Other suggestions include:
- Protein powders (such as whey, casein, soy or rice)
- Avoid foods low in calories and protein (salads, broth, jello)
- Eat small frequent meals (every 2-3 hours)
- Avoid drinking liquids with meals
- Consume liquids high in calories (juice, nutrition supplements)
Chemotherapy, radiation, and some infections can result in mouth sores, tender gums, sore throat and/or a sore throat. These problems often times also result in difficulties with eating resulting in weight loss. It is important to discuss these problems with your doctor to determine if these issues are related to treatment or perhaps due to developing dental problems. Your doctor can prescribe certain medications that can help with mouth and throat pain. Certain foods can also be irritating causing pain, or be difficult to chew and swallow. By practicing good oral hygiene and selecting non-irritating foods, eating is usually easier. Following are some foods to try:
- Milkshakes and smoothies
- Puddings, custards, ice cream, soups (not too hot)
- Commercially-prepared supplements such as Boost®, Instant Breakfast® or Ensure®
- Yogurt, cottage cheese
- Oatmeal or other cooked cereals
- Apple or grape juice; fruit nectars
- Scrambled eggs
- Macaroni & cheese, noodles, rice, potatoes
- Pureed foods or baby foods
Suggestions when chewing and swallowing are difficult :
- Puree foods or cook foods until tender
- Mix foods with gravies, sauces or butter/margarine to make it easier to swallow
- Drink liquids with meals
- Take small bites and chew foods thoroughly
- Tilt head forward or backward when swallowing
Avoid foods that are often irritating:
- Salty and spicy foods.
- Citrus foods - orange juice and grapefruit juice.
- Acidic foods such as tomato juice and salsa.
- Rough, coarse, dry or heavily textured foods.
- Raw vegetables.
- Eat foods cold or at room temperature; hot foods can be irritating.
Radiation and chemotherapy can cause a reduction in the production of saliva which can result in a dry mouth. This can make it difficult to chew and swallow food. A dry mouth may also change the way foods taste. Discuss with your physician the possibility of using products that help moisten your mouth called "artificial saliva." Additionally, following are some nutritional suggestions that may help make eating easier when this happens:
- Eat soft or pureed foods.
- Drink liquids after each bite of food.
- Moisten foods with sauces, gravies, or butter/margarine.
- Eat tart (lemon drops) or very sweet foods (popsicles) that may increase saliva production. However, very tart foods probably are not a good idea if you have mouth sores.
- Suck on hard candies or chew gum.
Nausea, with or without vomiting, is a common side effect of many of the therapies (chemotherapy, radiation, surgery, etc) used for the treatment of cancer. The cancer itself may also be a factor. There are different types of nausea and vomiting. Some patients experience nausea (with or without vomiting) immediately following treatment while others may not have it until several days following therapy (delayed nausea/vomiting). On the other hand, many patients never have nausea and/or vomiting during treatment. For those who do, this generally resolves once therapy is completed.
Many medications, called anti-emetics, are now available before, during or after treatment. Because nausea (with or without vomiting) can result in poor intake and weight loss, the following suggestions should be tried when this is a problem:
- Eat small frequent meals
- Eat bland foods such as saltines, pretzels, noodles, rice, potatoes and toast
- Try yogurts, smoothies, ice cream, sherbet, milkshakes
- Try carbonated beverages
- Try foods with ginger - ginger ale, ginger tea, ginger candies (1 gram of ginger taken daily as a supplement may also help)
- Try clear soups
- Eat foods at room temperature
- If nausea occurs during therapy, avoid eating 1-2 hours before treatment
- Stay hydrated
- Avoid spicy and fatty & fried foods
- Avoid foods high in caffeine
- Avoid foods that don't sound appealing
- Avoid foods with strong odors; avoid strong cooking odors
- Avoid eating favorite foods when feeling nauseated as this may diminish your enjoyment in these foods later
- Many times controlling nausea will prevent vomiting. A number of medications are available for the treatment of nausea. Therefore, if nausea is a persistent problem, it is important to discuss this with your doctor.
- Take anti-nausea medications 30 to 60 minutes before eating.
- Acupuncture and mediation may also help
If vomiting is a problem:
If vomiting is severe and lasts more than a day or 2, contact your physician. Do not eating until vomiting is under control; try to stay hydrated by drinking products such as Gatorade®, or Pedialyte®. Try drinking clear fluids such as apple juice and broth once vomiting is under control.
Once clear liquids are tolerated, try foods such as pudding, custards, ice cream and soups made with milk. Increase diet to solid as able.
Diarrhea is also a common side effect of many anti-cancer therapies. Infections, chemotherapeutic agents, radiation to the gastrointestinal tract, food sensitivities and intolerances, as well as stress, may contribute to this problem. With diarrhea, the body isn't able to properly absorb neither fluids nor important components of the foods such as vitamins and minerals. When diarrhea is sudden, consume nothing but clear liquids for the next 12 hours. This allows you to consume fluids to stay hydrated and allows your gastrointestinal tract to rest. Long-term diarrhea can result in dehydration and weight loss. It is important to discuss this with your doctor if diarrhea lasts more than a few days because identifying the cause is necessary in order to determine the best treatment. The following nutritional tips can help when diarrhea is a problem:
- Drink plenty of fluids; avoid caffeine-containing fluids such as coffee and colas as this may worsen diarrhea.
- Try sports drinks or Pedialyte® to obtain sodium, potassium and fluid.
- Eat small frequent meals throughout the day.
- Try decaffeinated teas, broth, toast, bananas, rice and applesauce.
- Eat bland foods such as saltines, noodles, and canned fruits.
- Eat lean meats, fish and chicken.
- Try oatmeal and rice hot cereals.
- Try fiber supplements such as Benefiber®, Citrucel® or Metamucil®.
- Greasy, fried and foods containing milk* may worsen diarrhea.
- Raw fruits and vegetables with skins, seeds and stringy pieces may also worsen diarrhea.
- High fiber vegetables such as corn, peas, broccoli and cauliflower should also be avoided.
* A condition such as lactose intolerance affects many people. Lactose intolerance is a condition where the body can't digest or absorb the sugar in milk called lactose. This frequently results in diarrhea, gas, bloating, and abdominal cramping and pain. Antibiotics, radiation and surgery to the gastrointestinal tract may result in this condition.
Constipation is the infrequent or difficult-to-pass dry, hard stool. There is no "normal" schedule for bowel movements rather constipation is usually diagnosed when there is a change in bowel movements when compared to usual habits. Some drugs, such as Herceptin®, anti-nausea, anti-depressants and pain medications, chemotherapeutic agents, vitamin and mineral supplements such as iron and calcium, inadequate fluid or fiber intake, and lack of exercise are factors that contribute to constipation. Depression and anxiety have also been reported as causes. The following nutrition recommendations can help prevent or minimize the likelihood of constipation, however, you should discuss this problem with your physician.
- Consuming adequate fluids - 8 to10 cups per day (8 oz/cup) - is extremely important. Fluids such as prune juice, lemonade and teas without caffeine can help.
- Eat foods high in fiber such as: fresh fruits & vegetables, legumes (beans such a pinto, kidney, garbanzo, baked, etc.), split peas, lentils and whole grains. Consume 25-35 grams of fiber daily but increase fiber intake slowly and drink plenty of fluids.
- Exercise daily if possible.
- Try bulk-forming agents such as Benefiber®, Citrucel®, Metamucil® or stool softeners such as Colace® or Dialose®.
Many side effects related to cancer and cancer treatments can result in weight loss. Involuntary and continued weight loss can result in malnutrition which has been associated with a lower tolerance to anti-cancer treatments, reduced quality of life, and a lower chance of survival. Many factors contribute to promoting weight loss such as the type of cancer (most common with pancreatic and head & neck cancers; least common with breast and prostate cancers), side effects of cancer therapies (such as poor appetite, mouth sores, nausea/vomiting, etc.), pain and depression. Identifying the potential cause(s) that may be contributing to weight loss is the key to preventing or stopping weight loss. The nutrition recommendations previously provided for a poor appetite are that the same suggestions that can help minimize weight loss or add a few pounds.
Many patients being treated for breast, ovarian and prostate cancer often gain weight which has been associated with an increased risk for recurrence. While the precise etiology is unknown, an increased intake of calories, many times from comfort foods, a decrease in physical activity, and medications prescribed during treatment are frequently cited as contributing factors. It is important to discuss this with your physician since some times the weight gain may be a side effect related to treatment. For example, some treatment regimens result in edema or fluid retension. It is also important to not go on a diet during treatment if you find you are gaining non-fluid weight. Instead, maintenance of weight is recommended with weight loss reserved for post-treatment.
Since weight gain is common in women being treated for breast cancer, a low fat diet and regular physical activity is generally recommended to avoid this side effect of treatment. Weight gain during treatment has been associated with increasing the risk for recurrence. Exercise on the other hand, has been associated with decreasing the risk for recurrent. Following are some additional tips:
- Eat lots of fruits and vegetables.
- Avoid high calories snack foods such as cookies, other sweets, chips, ice cream, and regular sodas.
- Consume lean proteins such as chicken, fish and lean cuts of meat.
- Consume lowfat dairy products: lowfat milks and cheese, yogurt and reduced-fat cottage cheese.
Fatigue commonly affects many patients going through treatment for cancer. While many factors such as the cancer itself, treatment, anxiety, depression, sleep disorders, medications and poor nutrition can contribute to the development of fatigue, the precise cause is poorly understood. There is no standard treatment for fatigue. The impact of fatigue varies from patient to patient and therefore, so does the recommendations for treatment. The potential causes should be identified and the appropriate treatment(s) instituted. Following are nutrition recommendations to consider:
- Eat small frequent meals every 3-4 hours.
- Consume nutrient-rich foods such as nuts, cheese, raisins, oatmeal made with milk or cream instead of water, peanut butter, etc.
- Consume iron rich foods: cream of wheat, red meat, molasses, fortified cereals and whole grains.
- Drink plenty of liquids (8-10 glasses daily).
- Take a multi-vitamin/mineral supplement daily.
- Change in sense of taste and smell
Chemotherapy, radiation and/or the cancer itself, may diminish the sense of taste, smell or both. Dental problems may also alter the taste of certain foods. Some foods, such as meats, often times have a metallic or bitter taste. Some foods just won't seem to have any taste. For most people, these changes go away after treatment is completed.
Although what particular foods may taste different varies from person to person, the following tips may help when you encounter these problems:
- To enhance the flavor, marinate meat, fish or chicken for 30-60 minutes before cooking.
- Add or increase the use of seasonings such as dill, cilantro, oregano, garlic, etc.
- Consider using onions, bacon or ham to flavor vegetables.
- Use plastic utensils instead of metal silverware if foods have a metallic taste.
- Practice good oral hygiene.
- Eat foods cold or at room temperature if smells bother you.
- Cook outdoors or cover foods when cooking.
- Put foods on the plate in another room before serving.
Eating Hints for Cancer Patients. Available at www.cancer.gov . Accessed January 10, 2006.
Goncalves Dias et al. Nutritional intervention improves the calorie and protein ingestion of head and neck cancer patients undergoing radiotherapy. Nutr Hosp. 2005;20:320-325.
Brown JK et al. Nutrition and physical activity during and after cancer treatment: an American Cancer Society guide for informed choices. CA Cancer J Clin. 2003;53:268-291.