What Not to Eat During Chemotherapy

Foods That May Cause Infection During Chemo

poached egg on bread
What foods should you avoid during chemotherapy treatment?. Jodie Louie/Moment/Getty Images

Are there any foods that you should avoid during chemotherapy? The short answer is: yes. Understanding why certain foods could be dangerous can help you stay healthy.

How Chemo Affects Your Taste Buds

When you're going through chemotherapy—and even for a while after—your formerly favorite comfort foods may not taste the same. Your beloved chocolate may take on a metallic aftertaste, or the childhood staple of mac 'n cheese can start to taste like wallpaper paste.

These are unfortunate side effects of some chemotherapy drugs. They can affect your taste buds in the oddest of ways. On the flip side, you might develop a taste for foods that you never used to enjoy.

Why Are Some Foods Taboo?

Chemotherapy suppresses your immune system, which may affect what you should and should not eat until your immune function is back to its full potential. Many people experience neutropenia related to chemotherapy. Neutropenia refers to a reduced number of white blood cells called neutrophils. These are white blood cells that fight off bacteria that enter the body. Ordinarily, when you eat foods containing harmful bacteria, these white blood cells fight them off and you're not aware of their presence. Chemotherapy can change that.

Certain foods—think raw or under-cooked foods—can actually make you sick. If your immune system is already tied up fighting on other fronts, the sickness can become more serious than a case of diarrhea or a bellyache.

According to the United States Department of Agriculture, 48 million Americans suffer foodborne illnesses annually. If your immune system is weakened, the chance of severe illness, hospitalization, and even death increases with one of these illnesses. Not only are ordinary infections worse than they otherwise would be, but you are more likely to develop infections that would never even begin if your immune system was in good order.

Foods to Avoid During Chemotherapy

Your oncologist or oncology nurse may have already informed you about which foods to avoid during chemotherapy, but make sure that you read to the bottom of this list. There will be times during chemo when your white blood cell count is higher or lower than others, but it's best to be safe and avoid certain foods even if you've just had your blood checked and it's normal. Most often, your white blood cell count will be lowest (at its nadir) 10 days to two weeks following a chemotherapy infusion, but this can vary. Foods to avoid include:

  • Unpasteurized dairy and under-cooked eggs: If it's got a runny yolk, avoid it. If it comes straight from the udder, avoid it.
  • Raw seafood: Oysters, most types of sushi, and other kinds of raw or undercooked seafood should be off the menu for now.
  • Unwashed fresh fruits and vegetables: Even "ready-to-eat" salad mixes and veggies must be carefully washed and peeled again, if possible.
  • Raw honey and associated products: Raw honey products can carry the botulism toxin and make you ill. This is the same reason why babies aren't supposed to eat honey.
  • Moldy cheeses: Think brie and blue cheese. Remember, the mold that gives these cheeses their taste and color is actually a fungus—a fungus that a healthy immune system can normally deal with, but that a compromised immune system may not.
  • Foods out of dented cans: The dents can actually compromise the integrity of the contents of canned foods and allow bacteria to form.
  • Raw nuts and fresh-made nut butter: These should also be avoided.

Hidden Ingredients

An important point is that some of the taboo foods listed above can be hidden in other products. Don't forget to exclude foods that are made with the above products, such as raw eggs in hollandaise sauce, Caesar salad dressing, or homemade mayonnaise. When in doubt, talk to your physician before eating the food in question.

Eating Out 

If you are immunosuppressed (have bone marrow suppression from chemotherapy), eating out may have to take a hiatus for now.

Think about how many hands the restaurant-prepared food that you eat travels through: the people in the warehouse, the people who transport it to the restaurant, the people who unpack it and store it in the facility, the people who set up and prep the food to be cooked, the chef, the waitress, and so on. Although a buffet of germs may not actually be present on your food, is it worth the risk?

Speaking of buffets, they should be avoided during and shortly after your chemotherapy, when your body has the least chance of fighting off common germs. Sneeze-shields (those little Plexiglas or glass dividers) are not foolproof, nor is there any guarantee that patrons aren’t revisiting the buffet with used plates, bowls, and utensils. Similarly, avoid any delicatessen or self-serve salad bars—opt instead to purchase the meat, lettuce, and toppings and clean them yourself at home.

Food Prep 

You've heard the adage about keeping hot foods hot and cold foods cold—but these are the specifics. Perishable foods should not be left out for protracted munching. After any meal or snack is served, the food should be packaged safely and refrigerated within at least two hours of preparation.

  • Cold foods must be kept at or less than 40 degrees Fahrenheit
  • Hot foods must be kept at or hotter than 140 degrees Fahrenheit

It's okay—and actually encouraged—to use multiple spoons, cutting and preparation surfaces, and pans while cooking. You don't want to contaminate the bacon by stirring it with the same fork that was used to whip your raw eggs, for example. Be sure to use a cutting surface that is not made of wood or another permeable surface while chopping or preparing raw meats—wood can harbor bacteria despite how well you wash it.

If you love a blood-red center in beef, consider swapping it for some well-cooked poultry—at least until your chemotherapy is over. Whatever meat or poultry you choose, make sure that it is cooked through. The best way to do this is not by "eyeballing it" or depending on a recipe's cook time; use a meat thermometer to figure out whether your meat is thoroughly cooked. And remember:

  • Poultry should be cooked to 165 degrees at the thickest part
  • Red meat should be cooked to 160 degrees at the thickest part
  • Reheated casseroles and leftovers should be heated to 165 degrees.

Be sure that your meat thermometer is not placed too shallow and it is not touching the bone if there is one, as both mistakes could cause a false reading.

Hand Washing Is Important

One of the most important things that you can do—and not just before eating or preparing food—is to wash your hands. It's been shown repeatedly that careful hand washing by yourself and others around you can do wonders in decreasing the risk of infections.

The "PICCY" Mnemonic 

Oncologists realize that all of this detailed information can be hard to remember—especially at a time when you are learning a massive number of facts about cancer. The mnemonic is "piccy" and goes as follows:

  • P: P stands for pasteurized. In other words, make sure that foods such as dairy products have been heated or say "pasteurized" on the packaging.
  • I: I stands for inspect. Take a careful look at any foods before eating them. For example, look for any cuts or breaks in veggies or fruits, or molds growing on other foods.
  • C: C stands for clean. Not only should you make sure to clean the foods that you eat, but be wary of cutting boards and other surfaces that your food may come in contact with that may not be clean. And always prepare food with clean hands. 
  • C: The second C stands for cook. Cook any meats, poultry, or seafood thoroughly.
  • Y: Y stands for yuck. Mark dates on any leftovers in your fridge and throw them out promptly. Consider that in order to identify a bacterium, scientists place a dab on a plate and let it grow for awhile in a fridge. Avoid making your own Petri dishes in your own fridge.

The Bottom Line

Avoiding foods that can cause infection in addition to coping with mouth sores, taste changes, and sometimes nausea or a loss of appetite from chemo can be difficult. That said, there are now several cookbooks that have been designed for people with cancer that can help you manage food restrictions.

Sources:

Centers for Disease Control and Prevention. Preventing Infections in Cancer Patients. Updated 11/18/15. http://www.cdc.gov/cancer/preventinfections/patients.htm

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