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Diet during Cancer Treatment

There are no current evidence-based recommendations for diet therapy during cancer treatment, due in part to the heterogeneous nature of this disease. Because of the frequency of loss of appetite and severe weight loss (cachexia) in many cancer patients, clinical efforts often focus on increasing protein and calorie intake by any means acceptable to patients. However, it is possible that patients on ad libitum diets high in fat, sugar, and animal protein (rather than on a more restricted yet therapeutic diet) may present a degree of long-term risk. Evidence suggests that by increasing cancer growth factors and stimulating cellular events leading to immune suppression and inflammation, such diets may foster proliferation and metastasis, interfere with effective treatment, and potentially worsen survival. These issues await further research.

However, for specific difficulties encountered during cancer treatment, dietary adjustments may be helpful:

Nausea and vomiting. The American Cancer Society and National Cancer Institute suggest the following strategies to control the nausea and vomiting associated with chemotherapy: 1-3

  • Eating small, frequent meals.
  • Using powdered or liquid meal replacements.
  • Drinking only small amounts of liquids with meals.
  • Avoiding noxious odors and sweet, fried, or fatty foods.
  • Using soft, cool, and/or frozen foods.
  • Keeping healthy snacks available.
  • Not lying flat for at least 2 hours after a meal.
  • Eating at least 1 hour before treatment.
  • Not eating for a few hours before treatment if chemotherapy usually causes nausea.
  • Eating before bedtime.
  • Having wine or beer with meals to stimulate appetite (assuming physician approval).
  • Exercise, as tolerated.

However, controlled clinical trials are needed to document the effectiveness of these recommendations.

Radiation enteritis. Symptoms of radiation enteritis include nausea, vomiting, abdominal cramping, tenesmus, and watery diarrhea. According to the National Cancer Institute, a diet that is lactose-free, low in fat, and low in residue can be effective in symptom management.4 However, evidence supporting this approach is minimal5 and requires confirmation in controlled trials.

Chemotherapy-related mucositis and stomatitis. Use of ice chips for 30 minutes before bolus administration of chemotherapy (eg, 5-FU) prevents mucositis6 and reduces symptoms by roughly half compared with a control group.7 In patients treated with chemotherapy for a variety of cancers, oral glutamine (2g/m2 delivered in a swish-and-swallow form or up to 4 gm/d orally) decreases the severity and duration of oropharyngeal mucositis, in addition to significantly reducing pain and the need for IV narcotics and parenteral nutrition.8,9 Glutamine supplementation was also found to decrease the incidence and severity of diarrhea, neuropathy, cardiotoxicity, and hepatic veno-occlusive disease that accompanies the use of many chemotherapeutic agents.10

Hypogeusia. Blunted taste sensation often occurs in patients undergoing chemotherapy and radiation. It occurs in up to 70% of chemotherapy-treated patients, and may contribute to lack of appetite and poor dietary intake, which, in turn, can worsen a patient's health status.11 Treatment with zinc sulfate (45 mg/d) reduces the occurrence of hypogeusia and speeds recovery of taste acuity in patients with head and neck cancer.12

In addition to the above considerations, some evidence supports the use of the following interventions:

Selenium supplements. In women receiving chemotherapy for ovarian cancer, selenium supplementation (200 µg/d) significantly increased white blood cell count and decreased hair loss, abdominal pain, weakness, malaise, and loss of appetite.13 Short-term treatment with high doses of selenium (4000 µg/d) reduces nephrotoxicity and bone marrow suppression in cisplatin-treated patients.14 Further clinical trials are needed to establish the benefit and lack of toxicity of selenium doses in excess of Dietary Reference Intakes.

Specialized enteral formulas. Patients who received surgical treatment for gastric or head and neck cancers and were fed formulas containing arginine, glutamine, omega-3 fatty acids, RNA (or a combination of these) had superior outcomes, compared with standard enteral formulas. The experimental group demonstrated higher levels of total and T lymphocytes, T helper and natural killer cells,15 and a significant reduction in postoperative infections and wound complications.16 However, further study is needed to confirm the superiority of specialized over standard formulas with respect to immune parameters and infection rates.

Behavioral interventions. Pharmacologic therapies are not completely effective in controlling these symptoms. Published studies support the effectiveness of behavioral interventions for chemotherapy-related nausea and vomiting, including hypnosis, guided imagery, relaxation, and distraction.3

Studies suggest that diet changes may reduce the likelihood of recurrence or other poor outcomes for certain types of malignancy. See Breast Cancer, Prostate Cancer, and Ovarian Cancer chapters for additional information.


See Basic Diet Orders chapter.

Nutrition consultation: The dietitian should counsel the patient and family on meeting the patient's energy needs, and make recommendations regarding protein-calorie supplements.

What to Tell the Family

Patients with cancer are often undernourished and malnourished. These problems may contribute to impaired treatment outcomes and increased morbidity. However, a more enlightened nutritional approach to diet than encouraging patients to eat ad libitum is called for, both during and after cancer therapy. Nutrition supplements (protein-calorie and micronutrient) may be of value, but their benefit appears to be limited and requires further assessment in controlled trials.


Diet during Cancer Treatment: References >>