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Nutrition in Cancer Care (PDQ®)

Patient Version
Last Modified: 12/28/2011

Overview of Nutrition in Cancer Care

Key Points for This Section


Good nutrition is important for cancer patients.

Nutrition is a process in which food is taken in and used by the body for growth, to keep the body healthy, and to replace tissue. Good nutrition is important for good health. Eating the right kinds of foods before, during, and after cancer treatment can help the patient feel better and stay stronger. A healthy diet includes eating and drinking enough of the foods and liquids that have the important nutrients (vitamins, minerals, protein, carbohydrates, fat, and water) the body needs.

When the body does not get or cannot absorb the nutrients needed for health, it causes a condition called malnutrition or malnourishment.

This summary is about nutrition in adults with cancer.

Healthy eating habits are important during cancer treatment.

Nutrition therapy is used to help cancer patients get the nutrients they need to keep up their body weight and strength, keep body tissue healthy, and fight infection. Eating habits that are good for cancer patients can be very different from the usual healthy eating guidelines.

Healthy eating habits and good nutrition can help patients deal with the effects of cancer and its treatment. Some cancer treatments work better when the patient is well nourished and gets enough calories and protein in the diet. Patients who are well nourished may have a better prognosis (chance of recovery) and quality of life.

Cancer can change the way the body uses food.

Some tumors make chemicals that change the way the body uses certain nutrients. The body's use of protein, carbohydrates, and fat may be affected, especially by tumors of the stomach or intestines. A patient may seem to be eating enough, but the body may not be able to absorb all the nutrients from the food.

Cancer and cancer treatments may affect nutrition.

For many patients, the effects of cancer and cancer treatments make it hard to eat well. Cancer treatments that affect nutrition include:

When the head, neck, esophagus, stomach, or intestines are affected by the cancer treatment, it is very hard to take in enough nutrients to stay healthy.

The side effects of cancer and cancer treatment that can affect eating include:

Cancer and cancer treatments may affect taste, smell, appetite, and the ability to eat enough food or absorb the nutrients from food. This can cause malnutrition (a condition caused by a lack of key nutrients). Malnutrition can cause the patient to be weak, tired, and unable to fight infections or get through cancer treatment. Malnutrition may be made worse if the cancer grows or spreads. Eating too little protein and calories is a very common problem for cancer patients. Having enough protein and calories is important for healing, fighting infection, and having enough energy.

Anorexia and cachexia are common causes of malnutrition in cancer patients.

Anorexia (the loss of appetite or desire to eat) is a common symptom in people with cancer. Anorexia may occur early in the disease or later, if the cancer grows or spreads. Some patients already have anorexia when they are diagnosed with cancer. Almost all patients who have advanced cancer will have anorexia. Anorexia is the most common cause of malnutrition in cancer patients.

Cachexia is a condition marked by a loss of appetite, weight loss, muscle loss, and general weakness. It is common in patients with tumors of the lung, pancreas, and upper gastrointestinal tract. It is important to watch for and treat cachexia early in cancer treatment because it is hard to correct.

Cancer patients may have anorexia and cachexia at the same time. Weight loss can be caused by eating fewer calories, using more calories, or both.

It is important to treat weight loss caused by cancer and its treatment.

It is important that cancer symptoms and side effects that affect eating and cause weight loss are treated early. Both nutrition therapy and medicine can help the patient stay at a healthy weight. Medicine may be used for the following:

  • To help increase appetite.
  • To help digest food.
  • To help the muscles of the stomach and intestines contract (to keep food moving along).
  • To prevent or treat nausea and vomiting.
  • To prevent or treat diarrhea.
  • To prevent or treat constipation.
  • To prevent and treat mouth problems (such as dry mouth, infection, pain, and sores).
  • To prevent and treat pain.

See the Nutrition Therapy in Cancer Care 1 section and the Treatment of Symptoms 2 section for more information.



Glossary Terms

advanced cancer (ad-VANST KAN-ser)
Cancer that has spread to other places in the body and usually cannot be cured or controlled with treatment.
anorexia (a-nuh-REK-see-uh)
An abnormal loss of the appetite for food. Anorexia can be caused by cancer, AIDS, a mental disorder (i.e., anorexia nervosa), or other diseases.
anxiety (ang-ZY-eh-tee)
Feelings of fear, dread, and uneasiness that may occur as a reaction to stress. A person with anxiety may sweat, feel restless and tense, and have a rapid heart beat. Extreme anxiety that happens often over time may be a sign of an anxiety disorder.
appetite (A-peh-tite)
A desire to satisfy a physical or mental need, such as for food, sex, or adventure.
cachexia (kuh-KEK-see-uh)
Loss of body weight and muscle mass, and weakness that may occur in patients with cancer, AIDS, or other chronic diseases.
cancer (KAN-ser)
A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Cancer cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
carbohydrate (KAR-boh-HY-drayt)
A sugar molecule. Carbohydrates can be small and simple (for example, glucose) or they can be large and complex (for example, polysaccharides such as starch, chitin or cellulose).
chemotherapy (KEE-moh-THAYR-uh-pee)
Treatment with drugs that kill cancer cells.
condition (kun-DIH-shun)
In medicine, a health problem with certain characteristics or symptoms.
constipation (KON-stih-PAY-shun)
A condition in which stool becomes hard, dry, and difficult to pass, and bowel movements don’t happen very often. Other symptoms may include painful bowel movements, and feeling bloated, uncomfortable, and sluggish.
depression (dee-PREH-shun)
A mental condition marked by ongoing feelings of sadness, despair, loss of energy, and difficulty dealing with normal daily life. Other symptoms of depression include feelings of worthlessness and hopelessness, loss of pleasure in activities, changes in eating or sleeping habits, and thoughts of death or suicide. Depression can affect anyone, and can be successfully treated. Depression affects 15-25% of cancer patients.
diagnosis (DY-ug-NOH-sis)
The process of identifying a disease, such as cancer, from its signs and symptoms.
diarrhea (dy-uh-REE-uh)
Frequent and watery bowel movements.
diet (DY-et)
The things a person eats and drinks.
digestion (dy-JES-chun)
The process of breaking down food into substances the body can use for energy, tissue growth, and repair.
esophagus (ee-SAH-fuh-gus)
The muscular tube through which food passes from the throat to the stomach.
gastrointestinal tract (GAS-troh-in-TES-tih-nul trakt)
The stomach and intestines. The gastrointestinal tract is part of the digestive system, which also includes the salivary glands, mouth, esophagus, liver, pancreas, gallbladder, and rectum.
immunotherapy (IH-myoo-noh-THAYR-uh-pee)
Treatment to boost or restore the ability of the immune system to fight cancer, infections, and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Agents used in immunotherapy include monoclonal antibodies, growth factors, and vaccines. These agents may also have a direct antitumor effect. Also called biological response modifier therapy, biological therapy, biotherapy, and BRM therapy.
infection (in-FEK-shun)
Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.
intestine (in-TES-tin)
The long, tube-shaped organ in the abdomen that completes the process of digestion. The intestine has two parts, the small intestine and the large intestine. Also called bowel.
lung (lung)
One of a pair of organs in the chest that supplies the body with oxygen, and removes carbon dioxide from the body.
malnutrition (mal-noo-TRIH-shun)
A condition caused by not getting enough calories or the right amount of key nutrients, such as vitamins and minerals, that are needed for health. Malnutrition may occur when there is a lack of nutrients in the diet or when the body cannot absorb nutrients from food. Cancer and cancer treatment may cause malnutrition.
medicine (MEH-dih-sin)
Refers to the practices and procedures used for the prevention, treatment, or relief of symptoms of a diseases or abnormal conditions. This term may also refer to a legal drug used for the same purpose.
mineral (MIH-neh-rul)
In medicine, a mineral is a nutrient that is needed in small amounts to keep the body healthy. Mineral nutrients include the elements calcium, magnesium, and iron.
nausea (NAW-zee-uh)
A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.
nutrient (NOO-tree-ent)
A chemical compound (such as protein, fat, carbohydrate, vitamin, or mineral) contained in foods. These compounds are used by the body to function and grow.
nutrition (noo-TRIH-shun)
The taking in and use of food and other nourishing material by the body. Nutrition is a 3-part process. First, food or drink is consumed. Second, the body breaks down the food or drink into nutrients. Third, the nutrients travel through the bloodstream to different parts of the body where they are used as "fuel" and for many other purposes. To give the body proper nutrition, a person has to eat and drink enough of the foods that contain key nutrients.
nutrition therapy (noo-TRIH-shun THAYR-uh-pee)
Treatment based on nutrition. It includes checking a person’s nutrition status, and giving the right foods or nutrients to treat conditions such as those caused by diabetes, heart disease, and cancer. It may involve simple changes in a person’s diet, or intravenous or tube feeding. Nutrition therapy may help patients recover more quickly and spend less time in the hospital. Also called medical nutrition therapy.
pancreas (PAN-kree-us)
A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.
prognosis (prog-NO-sis)
The likely outcome or course of a disease; the chance of recovery or recurrence.
protein (PROH-teen)
A molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.
quality of life (KWAH-lih-tee ... life)
The overall enjoyment of life. Many clinical trials assess the effects of cancer and its treatment on the quality of life. These studies measure aspects of an individual’s sense of well-being and ability to carry out various activities.
radiation therapy (RAY-dee-AY-shun THAYR-uh-pee)
The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.
recover (ree-KUH-ver)
To become well and healthy again.
side effect (side eh-FEKT)
A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.
stem cell transplant (stem sel tranz-plant)
A method of replacing immature blood-forming cells in the bone marrow that have been destroyed by drugs, radiation, or disease. Stem cells are injected into the patient and make healthy blood cells. A stem cell transplant may be autologous (using a patient’s own stem cells that were saved before treatment), allogeneic (using stem cells donated by someone who is not an identical twin), or syngeneic (using stem cells donated by an identical twin).
stomach (STUH-muk)
An organ that is part of the digestive system. The stomach helps digest food by mixing it with digestive juices and churning it into a thin liquid.
surgery (SER-juh-ree)
A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.
symptom (SIMP-tum)
An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.
therapy (THAYR-uh-pee)
Treatment.
tissue (TIH-shoo)
A group or layer of cells that work together to perform a specific function.
tumor (TOO-mer)
An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Tumors may be benign (not cancer), or malignant (cancer). Also called neoplasm.
vitamin (VY-tuh-min)
A nutrient that the body needs in small amounts to function and stay healthy. Sources of vitamins are plant and animal food products and dietary supplements. Some vitamins are made in the human body from food products. Vitamins are either fat-soluble (can dissolve in fats and oils) or water-soluble (can dissolve in water). Excess fat-soluble vitamins are stored in the body’s fatty tissue, but excess water-soluble vitamins are removed in the urine. Examples are vitamin A, vitamin C, and vitamin E.
vomit (VAH-mit)
To eject some or all of the contents of the stomach through the mouth.

Table of Links

1http://www.cancer.gov/cancertopics/pdq/supportivecare/nutrition/Patient/Page2#S
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2http://www.cancer.gov/cancertopics/pdq/supportivecare/nutrition/Patient/Page5#S
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