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Nutrition in Cancer Care (PDQ®)

Patient Version
Last Modified: 10/29/2013

Effects of Cancer Treatment on Nutrition



Surgery and Nutrition

Surgery increases the body's need for nutrients and energy.

The body needs extra energy and nutrients to heal wounds, fight infection, and recover from surgery. If the patient is malnourished before surgery, it may cause problems during recovery, such as poor healing or infection. For these patients, nutrition care may begin before surgery.

Surgery to the head, neck, esophagus, stomach, or intestines may affect nutrition.

Most cancer patients are treated with surgery. Surgery that removes all or part of certain organs can affect a patient's ability to eat and digest food. The following are nutrition problems caused by specific types of surgery:

  • Surgery to the head and neck may cause problems with:
    • Chewing.
    • Swallowing.
    • Tasting or smelling food.
    • Making saliva.
    • Seeing.

  • Surgery that affects the esophagus, stomach, or intestines may keep these organs from working as they should to digest food and absorb nutrients.

All of these can affect the patient's ability to eat normally. Emotional stress about the surgery itself also may affect appetite.

Nutrition therapy can help relieve nutrition problems caused by surgery.

Nutrition therapy can relieve or decrease the side effects of surgery and help cancer patients get the nutrients they need. Nutrition therapy may include the following:

It is common for patients to have pain, tiredness, and/or loss of appetite after surgery. For a short time, some patients may not be able to eat what they usually do because of these symptoms. Following certain tips about food may help. These include:

  • Stay away from carbonated drinks (such as sodas) and foods that cause gas, such as:
    • Beans.
    • Peas.
    • Broccoli.
    • Cabbage.
    • Brussels sprouts.
    • Green peppers.
    • Radishes.
    • Cucumbers.
  • Increase calories by frying foods and using gravies, mayonnaise, and salad dressings. Supplements high in calories and protein can also be used.
  • Choose high-protein and high-calorie foods to increase energy and help wounds heal. Good choices include:
    • Eggs.
    • Cheese.
    • Whole milk.
    • Ice cream.
    • Nuts.
    • Peanut butter.
    • Meat.
    • Poultry.
    • Fish.
  • If constipation is a problem, increase fiber by small amounts and drink lots of water. Good sources of fiber include:
    • Whole-grain cereals (such as oatmeal and bran).
    • Beans.
    • Vegetables.
    • Fruit.
    • Whole-grain breads.
    See the Constipation section for more information.

Chemotherapy and Nutrition

Chemotherapy affects cells all through the body.

Chemotherapy affects fast-growing cells and is used to treat cancer because cancer cells grow and divide quickly. Healthy cells that normally grow and divide quickly may also be killed. These include cells in the mouth, digestive tract, and hair follicles.

Chemotherapy may affect nutrition.

Chemotherapy may cause side effects that cause problems with eating and digestion. When more than one anticancer drug is given, more side effects may occur or they may be more severe. The following side effects are common:

Nutrition therapy can help relieve nutrition problems caused by chemotherapy.

Patients who have side effects from chemotherapy may not be able to eat normally and get all the nutrients they need to restore healthy blood counts between treatments. Nutrition therapy can help relieve these side effects, help patients recover from chemotherapy, prevent delays in treatment, prevent weight loss, and maintain general health. Nutrition therapy may include the following:

  • Nutrition supplement drinks between meals.
  • Enteral nutrition (tube feedings).
  • Changes in the diet, such as eating small meals throughout the day.

Radiation Therapy and Nutrition

Radiation therapy can affect cancer cells and healthy cells in the treatment area.

Radiation therapy can kill cancer cells and healthy cells in the treatment area. The amount of damage depends on the following:

  • The part of the body that is treated.
  • The total dose of radiation and how it is given.

Radiation therapy may affect nutrition.

Radiation therapy to any part of the digestive system often has side effects that cause nutrition problems. Most of the side effects begin a few weeks after radiation therapy begins and go away a few weeks after it is finished. Some side effects can continue for months or years after treatment ends.

The following are some of the more common side effects:

  • For radiation therapy to the head and neck
    • Loss of appetite.
    • Changes in the way food tastes.
    • Pain when swallowing.
    • Dry mouth or thick saliva.
    • Sore mouth and gums.
    • Narrowing of the upper esophagus, which can cause choking, breathing, and swallowing problems.
  • For radiation therapy to the chest
    • Infection of the esophagus.
    • Trouble swallowing.
    • Esophageal reflux (a backward flow of the stomach contents into the esophagus).
  • For radiation therapy to the abdomen or pelvis
    • Diarrhea.
    • Nausea.
    • Vomiting.
    • Inflamed intestines or rectum.
    • A decrease in the amount of nutrients absorbed by the intestines.

Radiation therapy may also cause tiredness, which can lead to a decrease in appetite.

Nutrition therapy can help relieve the nutrition problems caused by radiation therapy.

Nutrition therapy during radiation treatment can help the patient get enough protein and calories to get through treatment, prevent weight loss, help wound and skin healing, and maintain general health. Nutrition therapy may include the following:

  • Nutritional supplement drinks between meals.
  • Enteral nutrition (tube feedings).
  • Changes in the diet, such as eating small meals throughout the day.

Patients who receive high-dose radiation therapy to prepare for a bone marrow transplant may have many nutrition problems and should see a dietitian for nutrition support.

See the Stem Cell Transplant and Nutrition section for more information.

Biologic Therapy and Nutrition

Biologic therapy may affect nutrition.

The side effects of biologic therapy are different for each patient and each type of biologic agent. The following nutrition problems are common:

  • Fever.
  • Nausea.
  • Vomiting.
  • Diarrhea.
  • Loss of appetite.
  • Tiredness.
  • Weight gain.

Nutrition therapy can help relieve nutrition problems caused by biologic therapy.

The side effects of biologic therapy can cause weight loss and malnutrition if they are not treated. Nutrition therapy can help patients receiving biologic therapy get the nutrients they need to get through treatment, prevent weight loss, and maintain general health.

Stem Cell Transplant and Nutrition

Stem cell transplant patients have special nutrition needs.

Chemotherapy, radiation therapy, and medicines used for a stem cell transplant may cause side effects that keep a patient from eating and digesting food as usual. Common side effects include the following:

  • Changes in the way food tastes.
  • Dry mouth or thick saliva.
  • Mouth and throat sores.
  • Nausea.
  • Vomiting.
  • Diarrhea.
  • Constipation.
  • Weight loss and loss of appetite.
  • Weight gain.

Nutrition therapy is very important for patients who have a stem cell transplant.

Transplant patients have a very high risk of infection. High doses of chemotherapy or radiation therapy decrease the number of white blood cells, which fight infection. It is especially important that transplant patients avoid getting infections.

Patients who have a transplant need plenty of protein and calories to get through and recover from the treatment, prevent weight loss, fight infection, and maintain general health. It is also important to avoid infection from bacteria in food. Nutrition therapy during transplant treatment may include the following:

  • A diet of cooked and processed foods only, because raw vegetables and fresh fruit may carry harmful bacteria.
  • Guidelines on safe food handling.
  • A specific diet based on the type of transplant and the part of the body affected by cancer.
  • Parenteral nutrition (feeding through the bloodstream) during the first few weeks after the transplant, to give the patient the calories, protein, vitamins, minerals, and fluids they need to recover.

See the Low White Blood Cell Counts and Infections section for more information.