University of California San Francisco
Helen Diller Family Comprehensive Cancer Center

Food Safety During Cancer Therapy

While undergoing chemotherapy or radiation therapy, or in the period shortly after receiving therapy, food safety is very important, as your immune system may be weakened and, therefore, not as protective as it normally is.

> Download the latest Food Safety for People with Cancer brochure from the USDA/FDA

If you recently have undergone a transplant or if your white blood cell count is very low, it is extremely important to follow food safety guidelines. A good guideline to follow is to eat only those foods that have been freshly prepared in a clean environment and which have not been sitting out for any length of time. If you'd like to speak to one of the cancer center dietitians about your concerns, you can schedule an appointment through the UCSF medical practice where you are being seen.

Grocery Shopping

  • Check "sell by" and "use by" dates and do not buy items that are out of date
  • Do not buy or use any bulging, damaged, or deeply dented cans
  • Make sure that frozen foods feel solid and that refrigerated foods are cold
  • Do not buy cracked or unrefrigerated eggs
  • Place raw meat, poultry, and fish into a plastic bag
  • Store groceries promptly after shopping
  • Do not buy bulk foods from self-service bins

Food Preparation

  • Prepare food on surfaces that have been thoroughly washed in hot, soapy water. You can clean cutting boards in hot, soapy water or wash in your dishwasher (if the board is made from dishwasher-safe materials).
  • Use separate cutting boards for cooked foods and raw foods.
  • Do not use raw, unpasteurized eggs in uncooked foods, since raw eggs are the perfect medium for the growth of bacteria such as salmonella.
  • Discard eggs, egg mixtures, or prepared egg dishes left at room temperature for more than an hour.
  • Wash the tops of cans and the can opener before use.
  • All meats should be cooked until well-done and should have no remaining pink color.
  • Foods should be cooled inside the refrigerator rather than outside. A good way to do this is to divide large amounts of hot food into small, shallow containers for quick cooling in the refrigerator.
  • Do not eat perishable foods that have been left out of the refrigerator for more than two hours.
  • Do not eat foods that have been sitting in the refrigerator for more than three days. A helpful way to keep track is to put a date on prepared foods and other perishable, refrigerated items once they have been opened. It is also helpful to refrigerate only the amount of food that you will eat in two or three days and freeze the rest.
  • Thaw meats and fish in the refrigerator.
  • Throw away food that has any mold on it.
  • Never taste foods that look or smell strange.
  • Wash and rinse fruits and vegetables thoroughly before eating them.

Foods to Avoid

The following section provides a list of foods that are more likely to carry infection-causing organisms. In addition to the foods listed here, there may be other foods that your transplant center recommends that you avoid. In order to get a full listing of foods to avoid, make sure to discuss food safety guidelines thoroughly with your dietitian or medical provider.

  • Free food samples
  • Foods at potluck meals where you don't know how food was prepared or how long it was sitting out of the refrigeration
  • Food from sidewalk vendors, delicatessens, smorgasbords, buffets, and salad bars
  • Raw or undercooked meat, poultry, or fish and smoked fish such as lox
  • Raw eggs, Caesar salads containing raw egg, mayonnaise-based foods, custards, or other dishes that may contain raw eggs
  • Well water unless it has been tested and found to be safe
  • Unpasteurized honey, milk, cheese, and yogurt
  • Unrefrigerated cream
  • Soft cheeses made from unpasteurized or raw milk, such as feta, brie, blue-veined, and queso fresco
  • Soft-serve ice cream, milk shakes, and frozen yogurt from yogurt machines
  • Miso and tempeh
  • Unroasted nuts or nuts in the shell
  • Raw vegetable or seed sprouts such as alfalfa or bean

Discuss the use of vitamin/mineral supplements with your physician and dietitian, as they may interfere with various medications or may be harmful to major organs, especially the liver and kidneys. Be cautious if you are using nontraditional nutrition supplements, such as herbal preparations, as they may contain toxic impurities or infection-causing fungi, yeast, molds, or bacteria. These can be life threatening for a person with a weakened immune system.


For additional information or resources, please visit the Patient and Family Cancer Support Center (Mission Bay) at 1825 Fourth Street, First Floor or The Ida and Joseph Friend Patient and Family Cancer Support Center (Mount Zion)  at 1600 Divisadero Street, B-101on the first floor, or call (415) 885-3693.

The information in this publication is designed for educational purposes only and is not intended to replace the advice of your physician or health care provider, as each patient's circumstances are individual. We encourage you to discuss with your physician any questions and concerns that you may have.

Ida & Joseph Friend Cancer Resource Center