Foods to Avoid While Undergoing Cancer Treatment

If you are receiving chemotherapy or radiation therapy as part of your cancer treatment, you may have already discovered that there are some foods you’d rather avoid. Because some patients develop unpleasant side effects during cancer treatment, including nausea, mouth sores or even a change in the way some foods taste, you may find some foods less appetizing or harder to eat than others.

No matter how good a particular food may sound, however, there are some that should be avoided during cancer treatment and recovery, due to their increased risk of foodborne illness on a patient’s already weakened immune system. For these patients, even mild food poisoning can be very serious and lead to hospitalization or even death.

Foods for Cancer Patients to Avoid

In general, be vigilant about eating raw or undercooked foods, which can harbor several different types of bacteria including E. coli, listeria or salmonella, and may make you sick. Thorough cooking can eliminate these bacteria, as well as any bacteria or viruses which may have been passed to your food through improper or careless handling.

Taking precautions during food handling and preparation can help such as using extra care when washing fruits and vegetables, and in particular leafy green vegetables, which may harbor loose soil or other contaminants. Additional foods that should be avoided during or immediately following some cancer treatments include:

  • Unpasteurized juice, cider, milk, yogurt or backyard eggs
  • Refrigerated duck, chicken liver or other meat pate, since the organs used are not always cooked through and may harbor campylobacter or other bacteria
  • Chilled, ready-to-eat sandwiches, or deli-prepared salads made with egg, ham, chicken or seafood
  • Uncooked hot dogs, sliced cold cuts or uncooked cured salami, due to their increased risk of contamination with listeria
  • Smoked fish, including dips and spreads made with smoked fish
  • Shooting sprouts and leaves, including watercress, curry leaves and beansprouts like aduki, alfalfa, lentils and mung beans. Because these foods are often grown in warm, moist conditions, their cultivation creates a perfect environment for harboring salmonella and the E. coli present in some commercial fertilizers.
  • Soft cheeses made from unpasteurized milk, including most blue-veined cheeses, Brie, Camembert, feta, goat cheese, and queso fresco or queso blanco
  • Melons, including cantaloupe and watermelon, due to their increased risk of listeria contamination
  • Raw or undercooked beef, particularly ground beef, or any raw or undercooked meat or poultry. Remember, heat and fire kill most bacteria and viruses, so cooking all meats thoroughly is advised.
  • Raw or undercooked shellfish, including mussels, clams and oysters. Shellfish can contain norovirus, hepatitis A and other biotoxins. Thorough cooking destroys these contaminants.
  • Sushi, sashimi and some types of fish with high levels of mercury. Raw fish should be off-limits during cancer treatment, but even some types of cooked fish, including King mackerel, marlin, orange roughy, shark, swordfish, tilefish, ahi tuna and bigeye tuna should all be avoided due to their high mercury content.
  • Raw or undercooked eggs, including soft boiled, over easy or poached, and foods made with raw eggs, including homemade cookie dough
  • Reheated starchy foods, including rice, pasta and couscous. Because cooked rice is sometimes left standing at room temperature after cooking, bacteria can multiply rapidly in this warm, moist environment. Cooked starchy foods should be cooled quickly if they are going to be eaten later, or better still, cook only the amount you plan to use immediately.

If you are undergoing or have recently undergone cancer treatment, discuss the length of time you will need to avoid these foods with your health care team. Visit our Life During Cancer Treatment page for additional support and information for cancer patients.