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Nutrition and daily life

Raw and cooked: when to cook during treatment

People say raw vegetables are healthier. But during neutropenia raw food can be a source of infection. This section explains the difference between raw and cooked, when cooking is safer and how to keep vitamins.

Last updated: ~2 min read
Raw vegetables on one side of a board, cooked on the other.
Figure 1.Raw and cooked — Raw and cooked: when to cook during treatment

01Short answer

Cooking kills most bacteria, viruses and parasites, so cooked food is safer during neutropenia. Cooking reduces some vitamins (vitamin C) but improves absorption of others (lycopene, beta-carotene). Steaming and short boiling keep vitamins better. Agree your return to raw food after neutropenia with your team. Always cook meat, poultry and eggs fully.

02Simple explanation

Cooking kills germs.

During neutropenia: cooked.

Steaming keeps vitamins.

Meat and eggs: always fully cooked.

03Scientific explanation

Vitamins: vitamin C is lost with heat and water; lycopene and beta-carotene are absorbed better from cooked food.

Neutropenic diet: studies have not clearly shown that a strict "neutropenic diet" reduces infections; many centres now focus on food-safety rules, so follow your team’s guidance.

WHO: at least 400 g of fruit and vegetables a day is recommended; during treatment the amount may vary with appetite and your doctor’s advice.

FDA: wash produce under running water before cutting or peeling, because a knife can carry germs from the skin into the flesh.

04What happens in the body?

How to cook

Steaming, short boiling and baking. Use the cooking water in soup, where the vitamins stay.

Colourful vegetables in a bamboo steamer.
Figure 2.Steamed vegetables — Raw and cooked: when to cook during treatment

Storing cooked food

Cool cooked food within 2 hours, refrigerate it and eat it within 1–2 days.

Cooking through matters
Figure 3.Cooking through matters.

Washing and peeling

Wash your hands, rub the fruit under running water, dry it with a clean towel, then peel or cut it. Soap or bleach solutions are not needed.

Cut fruit

Keep cut fruit in the fridge and eat it within 1 day; do not leave it at room temperature for more than 2 hours.

05Fruit: four steps

Whole fruit, swap bruised, wash and peel, eat cut fruit soon.

Whole fruit — No spots.1Whole fruitNo spots.
Not bruised — Fresh and whole.2Not bruisedFresh and whole.
Wash and peel — Running water.3Wash and peelRunning water.
Eat soon — Fridge, 1 day.4Eat soonFridge, 1 day.
VitaminsA natural source.
FibreFor the gut.
SafetyWashing.

06Key points at a glance

TopicIn brief
How to cookSteaming, short boiling and baking. Use the cooking water in soup, where the vitamins stay.
Storing cooked foodCool cooked food within 2 hours, refrigerate it and eat it within 1–2 days.
Washing and peelingWash your hands, rub the fruit under running water, dry it with a clean towel, then peel or cut it. Soap or bleach solutions are not needed.
Cut fruitKeep cut fruit in the fridge and eat it within 1 day; do not leave it at room temperature for more than 2 hours.

07Key terms

Neutropenic diet
Rules limiting raw food during neutropenia.
Steaming
Cooking without food touching the water.
Neutropenia
Low neutrophils, raising infection risk.
Potassium
A mineral for the heart and muscles.
Fibre
The part of plants that helps the gut work.

08Key points

  • Cooked during neutropenia.
  • Steam your vegetables.
  • Cool cooked food quickly.
  • Wash under running water.
  • Eat cut fruit soon.

09Frequently asked questions

Do cooked vegetables keep their vitamins?

Yes; some decrease and others are absorbed better.

When can I eat salad again?

When your neutrophils recover; your team will tell you.

Does this fruit treat leukemia?

No. It is a pleasant part of eating, not a treatment.

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.

  1. Do cooked vegetables keep their vitamins?

  2. When can I eat salad again?

  3. Does this fruit treat leukemia?

My questions

12Sources

  1. Leukemia & Lymphoma Society. Diet Guidelines for Immunosuppressed Patients
  2. U.S. FDA. Selecting and Serving Produce Safely
  3. NHS. 5 A Day: what counts?
  4. National Cancer Institute. Eating Hints: Before, During, and After Cancer Treatment
  5. USDA. FoodData Central
  6. Food Standards Agency (UK). Cooking your food
  7. NHS inform. Preparing and cooking food safely
  8. World Health Organization (WHO). Salmonella (non-typhoidal) — fact sheet
  9. U.S. Food and Drug Administration (FDA). Selecting and Serving Fresh and Frozen Seafood Safely
  10. NHS. Fish and shellfish
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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