Nausea is one of the most common symptoms for cancer patients, along with fatigue and loss of appetite. But it’s a symptom that can loom larger than others—especially given the importance of adequate nutrition and hydration in supporting the body’s natural healing capabilities.

Luckily for patients undergoing radiation therapy, having side effects like nausea is far less common than for those undergoing chemotherapy. This is because chemotherapy affects the whole body, while radiation therapy is targeted on the specific part of the body for treatment. That said, when radiation therapy targets areas that are part of the gastrointestinal tract or when radiation is utilized in combination with chemotherapy, a patient is more likely to experience nausea.

Just like with any other symptom, if radiation causes nausea, it is important to report those symptoms to the treatment team. Not only is this useful information for future treatments, but the team can evaluate whether medication is needed to manage nausea.

There are also some methods that patients and their caregivers can utilize to manage nausea, vomiting, and other radiation therapy side effects—typically by changing eating and drinking habits. Read on to learn how some small changes can make a big difference.

Visit the FAQ page for more answers to common questions about radiation therapy side effects.

Eat smaller, more frequent meals

When thinking about nausea, it’s helpful to consider the entire gastrointestinal tract. Constipation can cause nausea or increase it, as the body can start to feel over full and backed up if it is having difficulty eliminating waste. Eating stimulates the reflex that causes waste to move through the gut, so eating small meals more frequently can actually help to relieve constipation and, by extension, nausea.

In addition, eating smaller meals is sometimes easier for patients with nausea to handle. It puts less strain on the stomach, especially when meals are low in fat, and it can help to settle the stomach better than larger meals eaten less often. In addition, keep the amount of work that the digestive system has to do to a minimum—cut your food into small pieces ahead of time and chew it well.

And when it comes time to go to radiation therapy, reduce side effects by avoiding meals 2-3 hours before treatments, just like you might avoid eating right before going to the gym or exercising.

Choose foods that are bland and easy to digest

Similarly, you can reduce the workload of your digestive system by choosing easily digestible foods. This could include low-fiber foods like eggs, oatmeal, white rice, and baked goods with refined wheat (such as white bread and pancakes). It could also include foods like toast, crackers, applesauce, canned or cooked fruits and vegetables, or lean meats and proteins. In general, cooking foods makes them easier to digest, so try to prepare all your foods so that they’re tender.

Of course, low-fiber foods can come with fewer bowel movements, so be sure to drink extra fluids. Until you know if your radiation therapy side effects include sensitivities to smell, it is a good idea to select foods with little to no aroma or to wait until your food cools completely before consuming it. Cold and room temperature foods tend to have a milder aroma, after all.

There are some foods that are better at counteracting nausea than others, such as ginger or peppermint. Many people also have success with dry foods such as crackers, pretzels, or toast, or starchy plain foods like rice, potatoes, and noodles.  Bananas and applesauce are both nutritious and easy to digest high-energy snacks. Clear broths are another good way to easily intake necessary calories and fluids.

Experiment with flavors

Cancer treatments often make certain foods taste different, so it’s important to be flexible. Dishes that you used to enjoy may taste odd or different to you and may require some adjustments to make them palatable.

If foods taste salty or bitter, add sweetness with maple syrup or jam. If, on the other hand, it’s too sweet, try adding salty or acidic flavors. If tender meat starts to wear on you, try marinating it first in acidic dressings, sauces, or wines. And try seasonings you haven’t tried before, as they may taste differently than you’re used to.

If you have strange tastes in your mouth or flavors stick around longer than they should, consider trying lemon or lime sorbet or frozen fruits like grapes to cleanse your palate.  In fact, many people with cancer find that tart foods, such as lemons or pickles, improve the flavor of liquids and other foods—although it’s important to be careful since these can also irritate the stomach.

Avoid rich, fatty, fried, and spicy foods

Anything that could cause inflammation or irritation should be avoided. Take care with spicy or overly acidic foods that could cause additional issues.

Fatty and greasy dishes, such as fried foods, take longer to digest than protein and carbs. Because fat takes longer to digest, it physically sits in your stomach longer than other foods, and this can cause bloating and stomach pain in addition to nausea. Many of these dishes also contain large amounts of salt, which can further irritate the system.

In addition to being hard to digest, foods like these often also have stronger aromas. Some chemotherapy and radiation treatment side effects include anticipatory nausea and vomiting, where individuals start to feel ill in the presence of certain triggers—such as strong smells like those from fatty dishes.

It is a good idea to be careful of other things that digest slowly, such as high fiber foods like tough meat and whole grains, or things that can cause upset stomach and irritation, such as alcohol.

Stay hydrated, but sip… don’t chug

Another possible cause of nausea is lack of hydration. The digestive system needs water to function properly, and too little liquid can cause blockages and backups that affect appetite and nausea. While it is important to drink liquids, it is best to sip on beverages throughout the day rather than drinking large amounts of water in a short span of time.

Beverages that are clear, like ginger ale, apple juice, herbal tea, and sports drinks, tend to go down easier, and it’s a good idea to avoid carbonation—either by choosing drinks without it or by letting the drinks go slightly flat. Try to avoid juices with pulp in them, such as coconut water or orange juice.

As an added bonus, increasing hydration not only helps with digestion, but it can also help with other common radiation therapy side effects like fatigue.

Take prescribed medication prior to treatment

Just like other symptoms, if radiation therapy causes nausea, pay attention and keep good records of when nausea occurs and what might have triggered it. For some patients, symptoms will be highest directly following treatment. If this is you and you have been prescribed anti-nausea medication, it’s a good idea to take the medication about thirty minutes to an hour before treatment so that it has time to be in effect when your symptoms are most noticeable.

Similarly, it might make sense to take anti-nausea medications on a regular schedule rather than when your symptoms are particularly bothering you, especially if you have meals or food at regular intervals. Essentially, taking the medications ahead of your triggers can ensure a much more enjoyable treatment experience.

Always discuss your personal experience with your care team to best determine a symptom management plan that works best for you.