Eating a Healthy Diet During Radiation Therapy Cancer Treatment

Posted on August 16, 2022 in Cancer

Written by Dr. Ward

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Radiation therapy is a type of cancer treatment that shrinks and destroys cancer cells. During radiation, it’s important to eat well. A proper diet for radiation therapy keeps the body and its immune system strong, giving it the nutrients it needs to promote the regrowth of healthy tissues. Eating well during radiation also maintains energy, helps patients tolerate radiation side effects, lowers risks of infection, and speeds up recovery.

“Food is a part of the medical treatment during cancer therapy,” says Shayna Komar, a registered dietician specializing in oncology. “It helps support a patient’s immune system and decreases side effects. Radiation can be tiring and tough on the body. What a person eats will help keep them strong enough to get the treatment they need.”

However, the nutrients and foods a person needs during cancer treatment vary based on the individual, how their body responds to radiation, the treatment area, and the length of treatment. While there is no one-size-fits-all radiation diet, there are some guidelines and tips that can help you find the best one during your cancer treatment.

How the Diet Can Change During Radiation Therapy

When it comes to healthy eating, we know that usually means eating plenty of vegetables and fruits. But what about milkshakes and gravy sauce? Would you ever expect those to be good for you too?

Your diet during radiation might include foods you wouldn’t normally eat when otherwise healthy. That’s because your body’s needs during radiation are different.

Calorie and protein needs increase during radiation to help keep weight stable. It is not uncommon for radiation therapy to zap a patient of their energy and lessen their appetite. Many patients feel nauseous, which also dampens the desire to eat. Therefore, calorie and protein needs are higher than usual.

Shayna Komar

What you eat during radiation therapy will be a combination of what tastes good and what your body needs during treatment. Your diet during radiation might include foods you wouldn’t normally eat when otherwise healthy. That’s because your body’s needs during radiation are different. For example, here are some of the ways that the key components of your diet may change:

Calories: Some radiation patients need a higher-calorie diet to make sure that the food they are able to eat provides the body with enough energy to promote healthy tissue growth.

“Patients should aim to consume 25 to 35 calories per kilogram of body weight,” says Vanessa Lara, a dietician with a background in cancer biochemistry. “For example, a 150-pound male should try to eat between 1,705 to 2,386 calories.”

Protein: Protein helps maintain muscle and supports a healthy immune system — both critical functions needed during radiation. That’s why many radiation patients also have high protein diets.

“While every food group is important, protein trumps them all during radiation,” says Komar. “Protein is used for growth, repair of body tissue, and immune system support.”

Vitamins and Minerals: Vitamins and minerals also help keep the immune system strong and support healthy tissue repair. Maintaining adequate levels can be important. You should discuss with your doctor whether vitamin supplements are recommended. In some cases, your doctor may recommend you stop certain supplements during radiation therapy.

“Supplements can be a safe way to ensure patients undergoing radiation therapy get enough vitamins and minerals,” says Lara. “However, they can also be harmful if taken improperly.”

Softer Foods: When radiation is directed towards the mouth or throat, it can cause irritation and mouth sores, making it difficult to eat certain foods. You may need to find softer foods, incorporate broths or sauces, or blend fruits and veggies into a smoothie that you can drink with a straw.

“Limiting the diet to only soft foods is usually recommended for patients having trouble chewing and swallowing,” says Lara.

Bloating and Diarrhea: Sometimes radiation can cause bloating or loose stools, requiring patients to adjust their diet to avoid gas-producing foods. A low-residue (low-fiber) diet may be recommended by your doctor to help manage diarrhea during treatment if that is an expected side effect.

“The low-residue diet consists of lower fiber, soft, mostly cooked foods without added spices,” says Komar. “A client can eat some raw fruits without seeds or peels as tolerated.”


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Food to Eat During Radiation Treatment

healthy foods to eat during radiation therapy treatment for cancer

Including these 5 components in a healthy diet during radiation therapy is a recipe for a swift recovery with fewer side effects. Radiation therapy can change how a patient’s body accepts certain foods and uses nutrients. Each radiation therapy patient reacts differently to treatment, but here are the basic guidelines for developing a diet while undergoing radiation therapy for cancer:

  • Pay attention to your side effects and how they affect your appetite. Discuss the changes with your doctor.
  • Plan ahead for changes to your diet.
  • Focus on nutrient-dense foods like fruits, vegetables, grains, and lean proteins. Avoid saturated fats, sugar, salt, and alcohol.
  • Change your eating habits and times. Eat smaller meals more frequently.
  • Stay hydrated. Water is best but there are other healthy options.

Listen To What Your Body Is Telling You

Most patients experience little or no side effects during cancer treatment, while some experience any of a number of side effects. Side effects can occur the same day or after treatment.

“Radiotherapy can come with side effects such as lack of appetite, taste changes, difficulty chewing and swallowing, and intestinal problems like diarrhea and nausea,” says Lara.

That’s because while radiation therapy mostly affects cancerous cells, it can impact healthy cells as well. When good cells are affected, patients may experience various side effects.

The location of the body targeted by radiation therapy can cause different side effects, including:

  • Nausea/vomiting
  • Lack of appetite or taste
  • Gas and bloating
  • Mouth sores
  • Difficulty swallowing
  • Dehydration
  • Weight loss

Throughout your treatment, listen to your body and adjust your diet according to what it is telling you. You may find only some foods taste good on a given day. Be flexible and make adjustments to the foods you eat during radiation treatment.

“Do not approach radiation treatment with a strict food plan,” says Komar. “Instead, listen to your body and take it one week at a time.”

Your radiation diet may include switching to a bland diet or adding lots of flavorful foods to your meals. Tell your doctor if you begin to experience any side effects from your radiation therapy.


Be Prepared – Stock Up On Healthy Foods

Another ingredient to a healthy diet during radiation therapy is to plan ahead.

  • Stock up your pantry with diverse and healthy foods.
  • Prepare and store healthy meals in your refrigerator and freezer before you begin therapy.
  • Always have your favorite snacks available at work or on the go.
  • A small amount of pre-planning and preparation will make it easy to eat well even if you are not feeling your best.


Eat Nutrient-Dense Meals

Eating nutrient-dense meals is a factor in recovery from radiation therapy. Eating high-calorie, low-nutrient meals will not give the body what it needs to heal and as a result, will slow-down recovery time. Choose fresh and colorful foods for your diet.

“The more colorful foods a person eats, the more likely they are to consume a variety of vitamins and minerals,” says Komar.

Here is a list of foods to include:

Fruits and vegetables

Eat a variety of fruits and vegetables including dark-green, red, and orange vegetables, beans, and peas. Make fruits and vegetables the focal point of every meal. If difficulty eating raw fruits or vegetables is experienced, try eating soft steamed or cooked vegetables and canned fruit. If digestion is uncomfortable due to cramping or gas, consider altering the amount of fiber in the diet to see if that helps. Fruits and vegetables are often high in fiber and may help with stool consistency, but may also lead to gas or loose stools that can be avoided.

Whole grains

Whole grains include brown rice, 100% whole-grain breads and rolls, and Steel Cut Oatmeal. Quinoa is a whole grain that is high in protein, lacks gluten, and is easy to prepare. Try substituting Quinoa for white rice in meals to increase your protein intake. In general, whole grains are more beneficial than processed carbohydrates like white breads.

Lean proteins

Eat a variety of protein-rich foods that are low in fat. Include seafood, lean meat and poultry, Greek yogurts, eggs, beans, soy products, and unsalted nuts and seeds. Some soy products are highly processed and not as good for you as other types of soy. Edamame (young soybeans in a pod) would be a good choice for adding healthy soy to your diet. It is recommended that individuals get at least 10% of calories from proteins and often a much higher percentage depending on your situation. Your doctor may recommend protein drink supplements to ensure you are getting adequate protein.


Break The Rules

Keeping a good diet during your radiation therapy may mean throwing your regular meal rules out and making up your own, new meal rules.

Eat Smaller Meals

Eating smaller meals, more often, is helpful when you are experiencing side effects from radiation therapy. Eating five small meals a day rather than three large meals will make food digestion easier and help avoid nausea.

“Resting sitting up after meals also allows proper digestion,” says Lara. “Do not lay down for at least two hours after meals.”

Eat Dinner for Breakfast

Break usual mealtime traditions by eating long-established meals at different times during the day. If you don’t feel like eating breakfast food early in the morning, try eating a small serving of baked chicken and rice or a cream or broth-based soup.

On the other hand, you might feel like eating breakfast foods for dinner. Don’t limit the types of healthy foods you eat based on the time of day.

“It’s important for patients to adopt an attitude of exploration during this time,” says Lara. “Instead of focusing on what the diet limits, focus on different foods that can still be tasty and fun.”


Drink Plenty Of Liquids

Hydration is an important aspect of a healthy radiation diet. It is recommended that individuals drink 3-4 quarts of liquid every day. Drinking lots of water is especially important if you experience diarrhea during radiation therapy.

“Good hydration flushes toxins out of the body and reduces treatment side effects such as nausea, weakness, bowel changes, and fatigue,” says Komar. “Staying hydrated can also help keep a patient from going into the cancer center for IV hydration.”

Keep a filled water bottle with you at all times and drink, drink, drink. Some Jello, pudding, popsicles and juice products are additional hydration sources, but be cautious of their sugar content. If you do not care for the taste of water, try sneaking water into soup broths, fruit shakes, and flavored teas.

Additional Eating and Drinking Tips for Radiation Therapy

  • Chew your food slowly. Take your time eating each small meal.
  • To make sure you’re getting enough calories during radiation, ask yourself, “What can I add to this meal to make it more nutrient-rich?” Think about topping your dishes with dressings and sauces. Or, think about adding extra ingredients you can add in or on top of your dishes.
  • Cook foods that smell good
  • Drink beverages that are high in healthy calories
  • Eat foods in a stress-free relaxing setting to make eating a positive experience
  • Eat every few hours vs waiting until you’re hungry

What Foods Should I Avoid During Radiation?

  • Excess processed sodium (salt)
  • Refined sugars
  • Unsaturated fats
  • An excess of alcohol
  • Some salt, ideally unrefined, is needed in all diets. Your doctor or dietitian can recommend how much salt you should consume based on your medical history.

In addition to foods to avoid that are listed above, spicy foods can cause gastrointestinal problems during radiation therapy. While nausea and diarrhea are symptoms of radiation therapy, spicy foods can lead to cramping, and diarrhea.

“One of the potential side effects of radiation therapy includes intestinal problems, such as bloating,” says Lara. “Patients should watch out for foods and dietary habits that may cause bloating such as cruciferous vegetables, carbonated beverages, and drinking from straws.”

If you are receiving radiation therapy for head and neck cancer, refrain from consuming foods that may get stuck when swallowing (e.g. dry bread) or those that are high in acid (tomato-based foods, etc.) which can be irritating.

In Summary

Listening to your body, being prepared, eating nutrient-dense meals, making your own mealtime rules, and drinking plenty of liquids is a recipe for success in treatment. By following these top 5 components to a healthy diet during radiation therapy, patients will improve their odds of staying active and strong during and after treatment.