Food safety when your immunity is low
If your immunity is very low due to cancer or its treatment, you might need to avoid certain foods. This can help reduce your risk of getting an infection.
Risk of infection (reduced immunity)
Cancer and some cancer treatments can weaken your immune system. If your immune system is weak, you are more at risk of infection and food poisoning. This is because you are less able to fight infections. You may also be less able to cope with the symptoms of food poisoning.
Following good food hygiene will reduce the risk of infection.
Related pages
General tips for good food hygiene
Before you cook, it is important to:
- Wash your hands before you prepare food, and before you eat.
- Clean cooking utensils and chopping boards thoroughly, especially after preparing meat or eggs.
- Wipe worktops with hot, soapy water or an anti-bacterial spray. This is very important if you have prepared raw meat or eggs.
- Wash or replace dishcloths and tea towels regularly.
- Keep pets out of the kitchen.
It is also important to do the following:
- Use fresh ingredients.
- Make sure your food is thoroughly cooked, especially meat and fish.
- Rinse all fruit and vegetables, including salads, in cold running water.
- Store food and drink at the correct temperature. Look at the packaging for storage instructions.
- Eat food before the best-before and use-by dates on the packaging.
- Throw away any mouldy food or food that has gone past the best-before or use-by dates.
- Be careful when eating out. Be aware of food choices and how food is prepared and cooked.
Foods to avoid if your immunity is low
For most people, low immunity will not last long, so there is no need to follow a special diet. But if you are having high-dose chemotherapy, or a stem cell or bone marrow transplant, your immunity may be very low.
If your immunity is very low, your healthcare team will advise you to avoid some foods for a certain amount of time. It is important to follow their advice.
Foods to avoid when your immunity is very low include:
- meat and fish pâté
- undercooked eggs with a runny yolk
- any product containing raw egg, such as homemade mayonnaise
- raw or undercooked meats, poultry, fish, or shellfish
- cold meats that have been smoked but not cooked, such as salami
- products that contain probiotics, such as some yoghurts
- food or drinks made from unpasteurised milk, such as some cheeses
- blue cheese (mould-ripened and blue-veined cheeses) such as Stilton cheese.
It is important to rinse with water all fruit, vegetables and salad before eating them. Your doctor, nurse or dietitian may advise you to peel fruit and vegetables.
Storing and reheating food safely
If you decide to store cooked food to eat later, let it cool down completely and then store it in the fridge or freezer.
Freezing extra portions is a useful thing to do before starting cancer treatment. It can save you time later. You must defrost food fully before reheating it.
If packaging says to cook an item from frozen, follow the cooking instructions. This is very important if you have low immunity because of treatment.
Only reheat food once, and make sure it is hot all the way through before you eat it. Do not reheat cooked rice. Eat rice as soon as it is cooked. If you are reheating food, take care not to burn your mouth or tongue.
Eating out when your immunity is low
If your immunity is low, it is best to avoid eating out and take-away food. If you eat out, try to choose as place where you know the food will be freshly prepared and properly cooked.
Avoid eating food from:
- salad bars
- buffets
- street vendors
- ice cream vans.
This is because it is difficult to know how fresh the food is.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
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References
Below is a sample of the sources used in our information about healthy eating and cancer. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk
The Eatwell guide. NHS. Available from www.nhs.uk/live-well/eat-well/food-guidelines-and-food-labels/the-eatwell-guide [accessed July 2025].
World Cancer Research Fund. Cancer risk factors. Available from www.wcrf.org/diet-activity-and-cancer/risk-factors [accessed July 2025].
British Dietetic Association website www.bda.uk.com [accessed July 20235].
Eat well, spend less. British Dietetic Association. Available from www.bda.uk.com/resource/food-facts-eat-well-spend-less.html [accessed July 2025].
Date reviewed
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