Cancer Colon Cancer Living With What to Eat When You Have Mouth Sores Non-irritating foods can help with oral mucositis By Suzanne Dixon, MPH, RD Updated on April 11, 2024 Medically reviewed by Oliver Eng, MD Print Table of Contents View All Table of Contents Causes Foods to Eat Food to Avoid How to Eat Coping When to Call Your Healthcare Provider The loss of appetite is common when undergoing cancer treatment, particularly if you get a common side effect called oral mucositis that causes mouth sores. To ensure proper nutrition to help you heal, you need to find non-irritating foods that you can eat even if you have mouth sores. This article explains why mouth sores occur in people undergoing cancer treatment. It also lists the types of food you can and cannot eat—as well as the way to eat—to better cope with treatment-induced oral mucositis. Oscar Wong / Getty Images How Cancer Treatment Causes Mouth Sores Over 40% of people undergoing certain cancer treatments will develop oral mucositis. It is most commonly associated with chemotherapy but can also occur with radiation therapy to the head or neck. Oral mucositis is an especially common occurrence when exposed to the chemotherapy drugs 5-fluorouracil (5-FU) or Evomela (melphalan). Other chemotherapy drugs can do the same. Treatment-induced oral mucositis is the result of the following processes: Whenever cells are damaged by chemotherapy or radiation, they release unstable atoms called free radicals. This, in turn, triggers the release of inflammatory chemicals called cytokines and metalloproteinase that break down a structural protein called collagen, causing tissues to thin and form ulcers. When this occurs in the mouth, natural bacteria quickly move into the sores, causing infection, inflammation, and pain. The sores 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. Foods to Eat If You Have Mucositis Generally speaking, you will want to eat foods that are soft, non-acidic, non-spicy, and not overly hot if you have oral mucositis. The less you have to chew, the better. Among the foods recommended for people struggling with oral mucositis are: Scrambled, poached, or boiled eggsCanned tuna fishStewed meatsSoft noodles and pastaWell-cooked white riceMashed vegetables, including potatoes sweet potatoes, peas, carrots, etc.Creamed spinach or cornCreamed or pureed soupsBaked beansTofuDairy products like milk, yogurt, and cottage cheeseSoft white breadCooked cereals, such as cream of wheat or thinned oatmealPancakesApplesauceBananasWatermelon, cantaloupe, papaya, and honeydew melonSoft stone fruits with thin skins, like apricots and nectarinesStewed or baked fruitsSmooth peanut butterCustards and puddingsGelatin dessertsPopsicles, ice cream, and frozen yogurtProtein shakes, smoothies, and liquid nutritional supplementsCaffeine-free teaNon-acidic juices, like apple juice or fruit nectars Honey’s efficacy in the treatment of oral mucositis in people with cancer has been well documented. It has been reported to alleviate the severity and duration of oral mucositis.Additionally, chamomile, curcumin, and green tea have been found to have benefits for those with oral mucositis. Food 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: Tough cuts of meatRaw or undercooked vegetablesTough or chewy bread, like bagelsCrunchy foods, such as pretzels, crackers, chips, or dry cerealTart or acidic foods, including tomatoes and citrus fruitsSalty or spicy foodsNuts or seedsHard or stringy fruits, like raw apples or mangosFruits with skins, like plumsFruits with little seeds, like strawberries, that can get stuck in soresHot foods, including soup and piping-hot beveragesCaffeinated beverages, including coffee, black tea, and colasAlcohol, including beer, wine, and liquor Foods to Avoid During Chemotherapy How to Eat if You Have Oral Mucositis Oral mucositis can be difficult to avoid when undergoing cancer treatment. Still, there are things you can do to get the nutrition you need without worsening the 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 large meals 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.Puree your food: If your mouth is too sore to chew, get a blender and puree it.Moisten your food: Gravy and broth are not only ideal for softening food but also provide added nutrition. You can also make food more slippery with a splash of olive oil or canola oil.Use a straw: Sucking drinks through a straw can help you bypass mouth sores. Nutritional Goals It is important to maintain balanced nutrition each day. To do so, you need to eat:Two servings of proteinTwo servings of dairyFive servings of fruits and vegetablesEight to 10 glasses of water or liquids Coping with Oral Mucositis In addition to being mindful of what and how you eat, the following can also help you manage mouth sore pain if you have oral mucositis: 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. Use an over-the-counter oral numbing spray like Chloraseptic. Quit smoking, which not only increases the risk of oral mucositis but makes it worse. Gargle with Magic Mouthwash, which is specifically formulated for oral mucositis. Homemade Oral Rinse Combine warm water (8 ounces), baking soda (1/4 teaspoon), and salt (1/8 teaspoon), use several times per day. Mouth Sores from Chemo: Why You Have Them and How to Get Rid of Them How to Deal With Dry Mouth In addition to mouth sores, radiation treatment can cause dry mouth (xerostomia). If you are experiencing dry mouth in addition to mouth sores, try the following to help keep the 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. What to Eat When You Have a Dry Mouth When to Call Your Healthcare Provider Let your healthcare provider know right away if: Mouth sores interfere with your ability to eat or drink Significant weight loss or signs of dehydration occur You notice a white coating on your tongue, increasing redness, or bleeding that may indicate an infection You run a fever (ask your oncologist what degree of temperature is a concern) 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 mouth sores. Additional medical actions to take: Ask your healthcare provider for recommendations to manage mouth sores. Get a dental cleaning and check-up, and try to have any necessary dental work completed before cancer treatment. If you are at risk for bleeding, ask your healthcare provider if it's OK to floss. Let your healthcare provider know if you notice changes like new or worsening sores or an increase in pain or sensitivity. Summary Mouth sores may be 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. 7 Ways to Eat Well During Chemotherapy 8 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Barbosa SCM, Pereira VBM, Wong DVT, et al. 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Mouth and Throat Problems: Cancer Treatment Side Effect. Villa A, Connell CL, Abati S. Diagnosis and management of xerostomia and hyposalivation. Ther Clin Risk Manag. 2015;11:45-51. doi.org/10.2147/TCRM.S76282 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 By Suzanne Dixon, MPH, RD Suzanne Dixon, MPH, MS, RDN, is an award-winning registered dietitian and epidemiologist, as well as an expert in cancer prevention and management. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit