How to Eat Well Despite Having Dry Mouth

A dry mouth ( xerostomia ) can be caused by autoimmune diseases like Sjögren’s syndrome, diabetes, certain medications, and dehydration. Cancer care is also a major cause of dry mouth.

Dry mouth is particularly important for cancer patients to address, since the discomfort that comes along with it can cause a change in eating habits at a time when good nutrition is especially critical to maintaining strength and fending off other effects of treatment.

In this article, you’ll learn why you get dry mouth from cancer treatments, how xerostomia affects your appetite, how to manage this side effect, and how to eat well so you get the nutrition you need.

What Is Dry Mouth?

Dry mouth is generally a side effect or symptom, not a condition. It happens when you don’t have enough saliva to keep the tissues of your mouth moist.

This can be annoying, causing thick, stringy saliva and increased thirst. But it can also cause problems like:

• Altered sense of taste
• Difficulty chewing and swallowing
• Cavities and tooth decay
• Cracked or damaged lips, tongue, and mouth tissues
• Bad breath
• Sore throat
• Trouble speaking
• Problems with dentures
• Gum disease

Sometimes, xerostomia can become very serious, leading to infections and other problems. Call your healthcare provider if:

• Your lips are dry, cracked, or bleeding
• You have mouth sores that prevent you from eating or won’t heal
• You’re having difficulty breathing
• You notice white patches in your mouth, which can signal an infection
  

Dry Mouth and Cancer Treatments

Both radiation and chemotherapy treat cancer by targeting fast-growing cells. The problem is that they don’t discriminate between those that are cancer cells and those that are not.

Healthy cells in the lining of your mouth are some that are affected. Cancer treatments slow them down, leading to damage, and ultimately dry mouth.

These treatments can also alter the balance of healthy bacteria in your mouth.

Radiation

You may get dry mouth if you have radiation treatment on your head, face, or neck. In addition to the effects mentioned above, radiation can directly damage your salivary glands, which produce saliva.

It may take several months or more after treatment ends for your saliva production to improve. There is a chance that it may never go back to normal, though.

Xerostomia from radiation tends to be longer lasting if your salivary glands themselves are the targets. In some cases, it may get worse over time.

If you have dry mouth during radiation, let your healthcare provider know. You may be able to use a medication called Duvoid (bethanechol) to stimulate saliva production. Acupuncture may also help.

Chemotherapy

Chemotherapy can make your saliva thick and cause your mouth feel dry. This is the result of cellular damage caused by treatment.

However, unlike with radiation, it’s usually a short-term problem. Most people have normal saliva again within two months of treatment ending.

Surgery

If you have cancer in your salivary glands, they may need to be surgically removed. In this case, you’ll permanently have dry mouth.

How Dry Mouth Affects Appetite

When you have dry mouth, eating can become something you avoid simply because its unpleasant.

Dry-mouth symptoms that can impact your eating habits include:

• Changing sense of taste
• A persistent bad taste in your mouth
• Mouth sores
• Difficulty chewing and swallowing
• Sore throat

Also note that chemotherapy, radiation, and cancer can all cause loss of appetite on their own as well.

Recap

Chemotherapy and radiation don’t distinguish between cancer cells and other fast-growing, but healthy cells in the body. That can lead to dry mouth and prompt changes in how things taste, mouth sores, problems with chewing and swallowing, and other symptoms that affect your eating.

Managing Dry Mouth

Your healthcare provider may prescribe medicine to help with your dry mouth. If you’re on medications that could be contributing, they may want to switch you to one that doesn’t have this side effect.

Drug Classes That Cause Dry Mouth

• Antianxiety drugs
• Antidepressants
• Allergy drugs
• Decongestants
• High blood pressure drugs
• Parkinson’s disease drugs

Ask your nurse for a mouth care plan that outlines when and how often to brush your teeth, whether you should use special mouth rinses, and other ways to keep your mouth healthy and prevent dryness.

Your medical team may also be able to suggest products that help you keep saliva flowing. Dry mouth remedies may include:

• Chewing gum
• Saliva substitutes
• Mouth moisturizers

Mouthwashes you find in the dental aisle of the drugstore often contain alcohol. That can make your mouth drier, so it’s best to avoid them or look for an option that's formulated for dry mouth.

Tips to Help You Eat Well

You have lots of options for making it easier to eat. Give these a try:

• If you can eat solid food, take small bites. Chew slowly and completely.
  
• Focus on soft, moist foods (e.g., canned fruit, yogurt, custard, or pudding). Use broth, sauces, or gravy to soften foods such as casseroles, potatoes, and meat.
• Cool your food. Eat soft-cooked chicken and fish that's room temperature. Let hot cereals cool down. Make your soups and stews lukewarm.
• Add slippery ingredients to make food easier to swallow. Olive, canola, avocado, or almond oil can work, as can yogurt, jelly, or jam.
  
• Suck on frozen fruit, such as grapes, peach slices, or cantaloupe or watermelon wedges.
• If it’s hard to eat solid food, find nutritious meal-replacement shakes or other nutrient-packed beverages like smoothies or juices.

Be sure to drink a lot of fluids with and between meals as well.

Some food and drink can increase dry mouth symptoms. Avoid:

• Alcohol
• Caffeine
  
• Spicy or salty foods

You should also avoid tobacco.

Summary

Dry mouth can be due to a variety of conditions and certain medications. Cancer treatments are one cause worth extra special attention.

Radiation dries the mouth by damaging the salivary glands. This symptom can be long-lasting. Chemotherapy dries the mouth by thickening the saliva. This usually goes away within a few weeks of stopping treatment.

Xerostomia can cause issues like tooth decay and gum disease, but it can also affect eating (and thus, nutrition) by altering one’s sense of taste, making it difficult to eat, and causing mouth sores.

Your medical team can help you find solutions, including medication and special mouth-moisturizing products. Eat soft foods and avoid things that are very hot or drying, such as caffeine.

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.

1. Cleveland Clinic. Dry mouth (xerostomia).
2. American Cancer Society. Benefits of good nutrition during cancer treatment.
3. National Library of Medicine: MedlinePlus. Dry mouth during cancer treatment.
4. Cancer Treatment Centers of America. Dry mouth.
5. American Society of Clinical Oncology. Dry mouth or xerostomia.
6. American Cancer Society. Mouth dryness or thick saliva.
7. Canadian Cancer Society. Dry mouth.
8. Pinto VL, Fustinoni SM, Nazário ACP, Facina G, Elias S. Prevalence of xerostomia in women during breast cancer chemotherapy. Rev Bras Enferm. 2020;73(suppl 4):e20190785. doi:10.1590/0034-7167-2019-0785
9. Cancer Treatment Centers of America. Loss of appetite.

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.

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