What foods and drinks should I avoid?

To keep from irritating inflamed parts of your mouth more, and to prevent them from getting worse or new sores from forming, it’s better to avoid the following foods and drinks until the wounds have healed:

• Alcoholic drinks
• Carbonated ("fizzy") drinks
• Hot foods and drinks
• Very spicy foods
• Acidic foods like tomatoes or citrus fruits
• Hard and sharp-edged foods like bread rolls, raw vegetables or chips (crisps)

What should I consider when preparing meals?

When you chew, the mucous membranes lining your mouth move. This stretches the sore areas, which can hurt. Eating soups or soft food can help to prevent this pain.

During cancer treatment, people may have inflammations in their mouth as well as nausea, loss of appetite or loss of taste. As a result, they may eat less and lose too much weight. Adding things like butter or cream to soups and puréed food may help. This keeps the meals easy to eat and ensures that you have more calories even when you eat smaller portions. The higher fat content also enhances the taste of the food, making it easier to avoid using a lot of spices.

It is also important to let cooked food cool down enough before you eat – or to simply eat cool meals. There are various dishes that taste good despite being cold – like savory soups made with buttermilk, or sweet foods like custard, mild quark cheese, yogurts or shakes. If you like it sweeter, you could add honey instead of sugar or eat a spoonful of pure honey every now and then. Some studies have shown that honey helps to relieve the pain caused by inflammations of the membranes lining the mouth in people who have cancer.

Keep up oral hygiene

Thorough oral and dental hygiene is important – not only to prevent inflammations in the mouth, but also when mouth sores have already developed. This means:

• Brushing your teeth after meals and before going to bed with a soft brush
• Rinsing your toothbrush carefully after brushing, letting it dry and replacing it regularly (every month)
• Cleaning dentures and wearing them less for as long as the inflammation lasts
• Cleaning the spaces between your teeth as you usually do, for instance with special interdental brushes (but if that's not part of your normal routine, you shouldn't start when you have an acute inflammation)
• Using non-alcoholic mouthwashes

What else is important?

It is also important to drink enough fluids, not smoke and regularly check the lining of your mouth in the mirror. If the pain gets worse, or if the mucous membranes swell, change color or bleed heavily, it's a good idea to see a doctor or dentist.

Sources

• Carvalho CG, Medeiros-Filho JB, Ferreira MC. Guide for health professionals addressing oral care for individuals in oncological treatment based on scientific evidence. Support Care Cancer 2018; 26(8): 2651-2661. [PubMed: 29470703]
• Deutsches Krebsforschungszentrum (DKFZ), Krebsinformationsdienst (KID). Fieber bei Krebs. Beschwerden und Behandlungsmöglichkeiten. 2021.
• Deutsches Krebsforschungszentrum (DKFZ), Krebsinformationsdienst (KID). Haut, Haare, Zähne: Mund- und Zahnpflege bei Krebs. 2010.
• Peterson DE, Boers-Doets CB, Bensadoun RJ et al. Management of oral and gastrointestinal mucosal injury: ESMO Clinical Practice Guidelines for diagnosis, treatment, and follow-up. Ann Oncol 2015; 26 (Suppl 5): v139-151. [PubMed: 26142468]
• Yang C, Gong G, Jin E et al. Topical application of honey in the management of chemo/radiotherapy-induced oral mucositis: A systematic review and network meta-analysis. Int J Nurs Stud 2019; 89: 80-87. [PubMed: 30352321]

• IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

  Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

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