Foods to Avoid During Cancer Treatment

April 29, 2014
Amber Bauer, ASCO staff

If your treatment has caused side effects like nausea, taste changes, or mouth sores, you probably have already started your own mental list of foods you'd much rather steer clear of. However, there are some foods that no matter how good they sound are probably best avoided due to the risk of foodborne illness, aka food poisoning. Because some treatments can weaken your immune system until at least a few weeks after they’ve ended (longer if you had a stem cell/bone marrow transplant), food poisoning is not something to tempt. The results of developing a foodborne illness can be serious.

Eating raw or undercooked foods is a common cause of food poisoning. Proper cooking destroys bacteria, but they can start to grow on cooked food if it is left out or in the refrigerator for too long. Food also can become contaminated when someone infected with a virus or other “bug” handles it.

Paying attention to food safety rules and being extra careful when handling, preparing, and storing food is definitely important. However, some people who are receiving or have recently finished cancer treatment should avoid some foods entirely, even if they may have eaten them with no problems in the past. These include:

  • Cold hot dogs or deli lunch meat (cold cuts)—Always cook or reheat until the meat is steaming hot.

  • Dry-cured, uncooked salami

  • Unpasteurized (raw) milk and milk products, including raw milk yogurt

  • Soft cheeses made from unpasteurized milk, such as blue-veined (a type of blue cheese), Brie, Camembert, feta, goat cheese, and queso fresco/blanco

  • Smoked fish

  • Deli-prepared salads with egg, ham, chicken, or seafood

  • Refrigerated pâté—Sorry foodies!

  • Unwashed fresh fruits and vegetables, especially leafy vegetables that can hide dirt and other contaminants

  • Unpasteurized fruit juice or cider

  • Raw sprouts like alfalfa sprouts

  • Raw or undercooked beef (especially ground beef) or other raw or undercooked meat and poultry

  • Raw or undercooked shellfish, like oysters—These items may carry the hepatitis A virus and should be cooked thoroughly to destroy the virus.

  • Sushi and sashimi, which often contain raw fish—Commercially frozen fish, especially those labeled “sushi-grade” or “sashimi-grade,” is safer than other fish, but check with your doctor, nutritionist, or another member of your health care team before eating these foods.

  • Undercooked eggs, such as soft boiled, over easy, and poached

  • Raw, unpasteurized eggs or foods made with raw egg, such as homemade raw cookie dough

Talk with your doctor or another member of your health care team about how long you should take food precautions and when you can return to eating certain foods again.

If you are receiving chemotherapy, it is OK to eat raw fruits and vegetables during treatment because they provide important nutrients. But it is important to wash these foods before eating them. Learn more about ASCO’s recommendations for exercise, diet, and weight management. (Note that this link takes you to a different ASCO website.)

Last reviewed May 2022.

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