Cheese: which are fine and which are not
Cheese is a good source of protein and calcium. But some cheeses, especially soft, mould-ripened and unpasteurised ones, can carry Listeria. This section explains how to choose cheese during treatment.

01Short answer
02Simple explanation
Hard, pasteurised: fine.
Mould-ripened and blue: no.
Market cheese: no.
Cooked: often fine.
03Scientific explanation
Listeria is found more often in soft and unpasteurised cheeses and causes serious infection in people with weak immunity.
WHO: foodborne illness is more severe in people with weakened immunity; the five keys are keep clean, separate, cook thoroughly, keep food at safe temperatures, and use safe water and raw materials.
04What happens in the body?
Pizza and lasagne
Cheese dishes cooked until steaming are usually safe.

Sliced cheese
Cheese in sealed packs is safer than cheese sliced at the counter.

Neutropenia
When neutrophils are low, even ordinary germs can cause serious infection, which is why the rules are stricter.
General rules
This section is part of the general food-safety rules in “Handwashing: the simplest protection” and “Eggs and dairy: safe choices” and “Food safety: four simple rules”.
05Safety: four steps
Check, swap the risky, prepare properly, use in time.







06Key points at a glance
| Topic | In brief |
|---|---|
Pizza and lasagne | Cheese dishes cooked until steaming are usually safe. |
Sliced cheese | Cheese in sealed packs is safer than cheese sliced at the counter. |
Neutropenia | When neutrophils are low, even ordinary germs can cause serious infection, which is why the rules are stricter. |
General rules | This section is part of the general food-safety rules in “Handwashing: the simplest protection” and “Eggs and dairy: safe choices” and “Food safety: four simple rules”. |
07Key terms
- Listeria
- A bacterium that grows even in the cold.
- Mould-ripened cheese
- Cheese with a white mould rind.
- Foodborne infection
- An infection spread through food or water.
- Neutropenia
- Low neutrophils.
08Key points
- Hard and pasteurised.
- No mould-ripened or market cheese.
- Cooked: fine.
- When in doubt, throw it out.
- Call if you have a fever.
09Frequently asked questions
Is feta OK?
Made from pasteurised milk in a sealed pack, usually yes.
I see mould on my cheese?
Throw soft cheese away; during neutropenia it is safer to discard hard cheese too.
Are these rules for ever?
No. They are usually relaxed as blood counts recover; your team will say.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Is feta OK?
I see mould on my cheese?
Are these rules for ever?
12Sources
- World Health Organization. Five Keys to Safer Food manual
- World Health Organization. Food safety fact sheet
- U.S. Food and Drug Administration. Safe Food Handling
- National Cancer Institute. Eating Hints: Before, During, and After Cancer Treatment
- Journal of the National Cancer Institute, 2018. Johnson SB et al. Use of Alternative Medicine for Cancer and Its Impact on Survival
- JAMA Oncology, 2018. Johnson SB et al. Complementary Medicine, Refusal of Conventional Cancer Therapy, and Survival Among Patients With Curable Cancers
- NHS. How to wash your hands
- Centers for Disease Control and Prevention (CDC). Preventing Listeria Infection
- FoodSafety.gov (U.S. Department of Health and Human Services). Cook to a Safe Minimum Internal Temperature
- U.S. Food and Drug Administration (FDA). Food Safety for Older Adults and People with Cancer, Diabetes, HIV/AIDS, Organ Transplants, and Autoimmune Diseases
Pizza and lasagne
Sliced cheese
Neutropenia
General rules