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Nutrition and daily life

Mouth sores (mucositis): making eating easier

Chemotherapy and radiotherapy can damage the lining of the mouth; this is called mucositis. Sores are painful, make eating and drinking hard and open a door to infection. This section covers mouth care and which foods are easier to eat.

Last updated: ~1 min read
Mash, porridge and yogurt on a tray.
Figure 1.Soft foods — Mouth sores (mucositis): making eating easier

01Short answer

Choose soft, smooth foods at room temperature or cool: mash, porridge, yogurt, eggs, cooked fruit. Avoid acidic, spicy, salty, hard and crunchy foods, alcohol and very hot drinks. Use a soft toothbrush and rinse often with the simple rinse your team recommends. Let your doctor prescribe pain relief. Tell your team if pain stops you drinking, if white patches appear or if you have a fever.

02Simple explanation

Soft, cool food.

Away from acidic and spicy.

Soft brush and rinses.

Cannot drink? Tell us.

03Scientific explanation

NCI: oral mucositis is a common side effect of chemotherapy and radiotherapy; mouth care, soft food and pain control are the main measures.

ESPEN: enough energy and protein matter for preventing weight and muscle loss in people with cancer, and nutritional status should be assessed regularly.

NCI: practical eating tips exist for treatment side effects such as nausea, taste changes and mouth sores.

04What happens in the body?

Making eating easier

Moisten food with sauce, cut it small and use a straw if needed.

A brush and rinse cup on a shelf.
Figure 2.A soft brush — Mouth sores (mucositis): making eating easier

Mouth care

Gentle brushing and rinsing after every meal and at bedtime; avoid alcohol-based mouthwashes.

Lemon and chili at the edge, soup at centre.
Figure 3.Acidic and spicy aside.

Dietitian

If you are losing weight, have no appetite or need a special diet, ask to see the hospital dietitian.

Food safety

Food-safety rules for neutropenia (see “Handwashing: the simplest protection” and “Eggs and dairy: safe choices”) apply at every stage.

05Nutrition: four steps

Assess, swap the risky, cook safely, eat regularly.

Assess — Weight and appetite.1AssessWeight and appetite.
Swap — A safe choice.2SwapA safe choice.
Cook — Hot throughout.3CookHot throughout.
Eat regularly — Small portions.4Eat regularlySmall portions.
StrengthEnergy.
ProteinFor muscle.
SafetyFood rules.

06Key points at a glance

TopicIn brief
Making eating easierMoisten food with sauce, cut it small and use a straw if needed.
Mouth careGentle brushing and rinsing after every meal and at bedtime; avoid alcohol-based mouthwashes.
DietitianIf you are losing weight, have no appetite or need a special diet, ask to see the hospital dietitian.
Food safetyFood-safety rules for neutropenia (see “Handwashing: the simplest protection” and “Eggs and dairy: safe choices”) apply at every stage.

07Key terms

Mucositis
Inflammation and ulceration of the lining.
Thrush (candidiasis)
A fungal mouth infection with white patches.
Dietitian
A nutrition specialist.
Protein
A nutrient for repairing muscles and tissues.
Neutropenia
Low neutrophils.

08Key points

  • Soft and cool.
  • Rinse often.
  • Do not hide pain.
  • A diet is not a treatment.
  • Talk to a dietitian.

09Frequently asked questions

Which rinse?

The one your team advises, often water, salt or baking-soda solution.

Does ice help?

With some treatments sucking ice is advised; ask your team.

Can a special diet cure leukemia?

No. Good nutrition helps you cope with treatment, but it does not cure.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. Which rinse?

  2. Does ice help?

  3. Can a special diet cure leukemia?

My questions

12Sources

  1. NCI PDQ. Oral Complications of Chemotherapy
  2. National Cancer Institute. Eating Hints: Before, During, and After Cancer Treatment
  3. ESPEN. ESPEN practical guideline: Clinical Nutrition in cancer (2021)
  4. Leukemia & Lymphoma Society. Food and Nutrition
  5. World Health Organization. Healthy diet fact sheet
  6. NIH Office of Dietary Supplements. Magnesium — Fact Sheet for Consumers
  7. World Health Organization (WHO). Anaemia — fact sheet
  8. World Health Organization (WHO). Cancer: Carcinogenicity of the consumption of red meat and processed meat (Q&A)
  9. NHS. Can reheating rice cause food poisoning?
  10. U.S. FDA. Bad Bug Book: Phytohaemagglutinin (kidney bean lectin)
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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