How to Build the Best Diet for Radiation

How to Build the Best Diet for Radiation

Reviewed by Jasper Clinical Board

Last updated 5/24/21

Why it matters

Research shows that the overwhelming majority of people who receive radiotherapy experience nutritional decline—which means weight loss and lowered BMI, as well as drops in other more nuanced measures of nutritional status. This happens even with strategic nutritional interventions, and you need plenty of stamina to get through treatment, so it’s important to do everything you can to strengthen your body and fight malnourishment.

Diet staples

Okay, let’s get specific. What, exactly, should you be eating? The answer to that question will depend somewhat on your personal preferences, and on the type and severity of your side effects. A good guideline, however, is to start with just getting enough calories. Some people find it helpful to track their intake with an app like MyFitnessPal to make sure they are hitting their daily targets. No matter how good your food choices are, if you’re not taking in enough calories, you’ll experience weight loss, fatigue, and weakness, so it’s important to make caloric intake your first priority. If you’re struggling to eat enough, just eat what you can tolerate. 
To further fine tune your treatment nutrition plan, focus on protein, carbs, and fat. Protein is key during cancer treatment, because it helps your body rebuild damaged cells and tissues. Find it in lean meats, eggs, and dairy (beans and nuts if you’re plant-based). If eating is a struggle due to side effects, supplementing with protein powder is a totally reasonable choice (just watch out for artificial sweeteners—organic brands with whole-food ingredients are your best bet).
Carbs are more than just bread! Fruit, vegetables, and grains are all carbohydrate sources, which provide energy, and are often palatable even during periods of low appetite. If you’re struggling to get anything down, mashed sweet potatoes with olive oil or grass-fed butter is a comforting and highly digestible snack option. (Pro tip from the bodybuilding world: sneak in some unflavored protein powder for an additional boost.)
Healthy fats help your body absorb the other nutrients you consume, increase satiety, and keep your skin in good shape, which is a big deal during radiation. Choose avocados, organic oils, and high fat dairy like ghee, butter, and cheese. Nuts can be hard to digest, so tread carefully, but if you tolerate them well, they are an excellent (and convenient) source of quality fat.

Strategies for side effects

Side effects from radiation vary, largely based on your treatment site, and accumulate, so eating may be easier in the early stages of your treatment cycle than toward the end. Load up on fruit and vegetables, and other sources of vitamins and minerals like fatty fish and organ meats while you can—laying nutritional groundwork can help see you through the days where all you can muster is plain rice. 
If you’re receiving radiation to your abdomen, digestive side effects are common, which means you’ll want to opt for bland meals that don’t ask too much of your system, like soups and smoothies. Mouth and throat sores tend to go with head and neck treatment, so if that’s your protocol, you’ll want to nix anything acidic like citrus, tomatoes, and strawberries, and consider boiled food that is soft in texture.

Foods to avoid

During your treatment cycle, your immune system is not the toughest, so you’ll want to avoid common sources of food borne illness, like raw fish (sadly, this includes sashimi), unpasteurized cheese, and undercooked meat and eggs. Fruit and vegetable rinds can also harbor bacteria, so peeling them is a good idea, and make sure to go over your list of vitamins and supplements with your oncology team—even common vitamins can sometimes interfere with treatment efficacy, and it’s better to be on the safe side. 

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