Non-Irritating Foods to Eat When You Have Mouth Sores

What You Can Do About Oral Mucositis

While loss of appetite can result from some cancer therapies, finding foods to eat that won't irritate mouth sores—another potential side effect of some treatments—can be another challenge to getting the nutrition your body needs.

It's easy to end up limiting your diet when trying to avoid irritating painful mouth sores any further. But good nutrition during and after cancer treatment is important to healing, keeping your strength up, and much more.

This article explains why mouth sores occur in people undergoing cancer treatment. It also reviews what foods can irritate sores more than others and how to eat and keep pain to a minimum.

Person tossing blueberries into blender to make a smoothie

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How Treatment Causes Mouth Sores

Mouth sores (oral mucositis) are common among people undergoing cancer treatment.

The sores form on the inside lining of the mouth or lips and can often be extremely painful, making it difficult to eat, talk, and swallow. The sores may even extend into the esophagus that carries food from the mouth to the stomach.

Both chemotherapy and radiation can cause mouth sores. Chemotherapy not only targets cancer cells but other fast-replicating cells, including the mucosal tissues of the mouth.

Radiation impairs the body's immune system, increasing your vulnerability to infection.

Both of these factors contribute to the development and severity of mouth sores.

What (and How) to Eat

Oral mucositis may be difficult to avoid when undergoing cancer treatment. Still, there are things you can do to get the nutrition you need without worsening your pain.

This not only involves the types of food you eat, but also the way that you eat.

Among some of the more helpful tips;

  • Eat smaller, more frequent meals: Instead of three squares a day, try five to six snack-sized meals that place less stress on the mouth.
  • Take smaller bites: It often helps to cut your food into small pieces before starting to eat.
  • Eat soft or pureed foods: Think smoothies, shakes, yogurt, puddings, puréed soups, scrambled eggs, and stewed fruits. Cook food extra well, especially meat and vegetables.
  • Soften food with liquids: Try thinning cooked cereals with extra milk or mashed potatoes with extra cream or gravy. Olive oil or cheese sauce can also make pasta, meats, or vegetables slippery and easier to swallow.
  • Enjoy frozen snacks: In addition to popsicles, try frozen grapes, cantaloupe, peaches, or watermelon.
  • Eat water-rich fruits: This includes melons, peaches, and grapes.
  • Use a straw: Sucking drinks through a straw can help you bypass mouth sores.


If you have oral mucositis, the way that you eat is as important as what you eat. In addition to eating soft, well-cooked foods, try eating smaller meals, taking smaller bites, and using a straw.

Foods to Avoid

There are certain foods that can aggravate mouth sores and make the pain worse. Even before starting cancer treatment, take heed of the types of food you should avoid, including:

  • Caffeinated beverages, including coffee, black tea, and colas
  • Alcohol, including beer, wine, and liquor
  • Tough cuts of meat
  • Raw or undercooked vegetables
  • Tough or chewy bread (like bagels)
  • Crunchy foods, such as pretzels, crackers, chips, or dry cereal
  • Tart or acidic foods, including tomatoes and citrus fruits
  • Salty or spicy foods
  • Hot foods, including soup and piping-hot beverages

Other Pain-Relief Strategies

In addition to being mindful of what and how you eat, the following can also help you manage mouth sore pain:

  • Drink ice water or suck on ice chips to cool the mouth and bring down inflammation.
  • Take care of your teeth and gums by gently brushing and flossing.
  • Gargle with Magic Mouthwash, which is specifically formulated for oral mucositis.
  • Use an over-the-counter oral numbing spray like Chloraseptic.
  • Quit smoking.


Oral mucositis causes painful mouth sores that can make eating and swallowing difficult. The pain can be relieved by sucking on ice chips, caring for your teeth, quitting cigarettes, and using Magic Mouthwash or an over-the-counter numbing spray.

When You Also Have Dry Mouth

In addition to mouth sores, radiation can cause dry mouth (xerostomia).

If you are experiencing dry mouth in addition to mouth sores, try the following to help keep moisture levels up:

  • Chew sugarless gum to promote saliva production.
  • Use a saliva substitute like OraCoat or Biotene.
  • Stay well hydrated.
  • Snack on water-filled fruits like grapes and watermelon.
  • Avoid caffeine and alcohol, both of which can dry the mouth.
  • Quit cigarettes.


Dry mouth (xerostomia) is a common side effect of radiation therapy. You can treat it by staying well hydrated, chewing gum, using a saliva substitute, and avoiding caffeine, alcohol, and cigarettes.


Mouth sores are a side effect of chemotherapy and radiation. They can make it difficult to eat, drink, and swallow. You can relieve the pain with things like ice chips, Magic Mouthwash, numbing sprays, and eating smaller, more frequent meals.

The foods you eat can also make a big difference. Choose foods that are soft, well-cooked, cold, or pureed. Avoid spicy, hot, salty, acidic, or crunchy foods, as well as caffeine and alcohol.

A Word From Verywell

Preparation almost always makes cancer treatment easier. Before you even start chemo or radiation, ask your cancer specialist (oncologist) or care team about their recommendations for managing mouth sores.

If mouth sores are undermining your nutrition or quality of life, let your doctor know. In severe cases, a medication called Kepivance (palifermin) can be prescribed.

Delivered intravenously (into a vein), Kepivance stimulates the growth of mucosal tissues and helps reduce the size and pain of mucositis mouth sores.

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  1. Lauritano D, Petruzzi M, Di Stasio D, Lucchese A. Clinical effectiveness of palifermin in prevention and treatment of oral mucositis in children with acute lymphoblastic leukaemia: a case-control study. Int J Oral Sci. 2014 Mar;6(1):27-30, doi:10.1038/ijos.2013.93