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Nutrition and daily life

Preserves and jam: the sweetness of the table

Quince, cherry, apricot and walnut preserves are an essential part of the tea table. Cooked and properly sealed preserves are usually safe, but once opened and when stored at home there is a mould risk.

Last updated: ~1 min read
Jars of jam on a shelf.
Figure 1.Sealed jars — Preserves and jam: the sweetness of the table

01Short answer

Shop-bought jam in a sealed jar with an intact lid is usually safe. Homemade preserves that were well cooked and sealed in clean, sterilised jars are often fine; agree this with your team during neutropenia. Throw away the whole jar if the lid bulges or the jam is foamy, smells sour or of alcohol, or shows mould; scooping off the mould is not enough. Keep opened jars in the fridge and use a clean spoon. Preserves are high in sugar, so eat little with diabetes or on steroids.

02Simple explanation

A sealed jar.

Mould? Throw it all out.

Opened: in the fridge.

A clean spoon.

03Scientific explanation

Studies: moulds can root deep below the surface of jam, and some produce toxins.

ESPEN: enough energy and protein matter for preventing weight and muscle loss in people with cancer, and nutritional status should be assessed regularly.

NCI: practical eating tips exist for treatment side effects such as nausea, taste changes and mouth sores.

04What happens in the body?

Sugar

A teaspoon of jam is roughly a teaspoon of sugar.

A mouldy jar in shadow.
Figure 2.Mouldy jam — Preserves and jam: the sweetness of the table

Home canning

Poorly prepared low-acid home preserves carry a botulism risk.

Jam on toast and tea.
Figure 3.Tea time — Preserves and jam: the sweetness of the table

Dietitian

If you are losing weight, have no appetite or need a special diet, ask to see the hospital dietitian.

Food safety

Food-safety rules for neutropenia (see “Handwashing: the simplest protection” and “Eggs and dairy: safe choices”) apply at every stage.

05Nutrition: four steps

Assess, swap the risky, cook safely, eat regularly.

Assess — Weight and appetite.1AssessWeight and appetite.
Swap — A safe choice.2SwapA safe choice.
Cook — Hot throughout.3CookHot throughout.
Eat regularly — Small portions.4Eat regularlySmall portions.
StrengthEnergy.
ProteinFor muscle.
SafetyFood rules.

06Key points at a glance

TopicIn brief
SugarA teaspoon of jam is roughly a teaspoon of sugar.
Home canningPoorly prepared low-acid home preserves carry a botulism risk.
DietitianIf you are losing weight, have no appetite or need a special diet, ask to see the hospital dietitian.
Food safetyFood-safety rules for neutropenia (see “Handwashing: the simplest protection” and “Eggs and dairy: safe choices”) apply at every stage.

07Key terms

Mould
A fungus growing on food.
Sterilisation
Cleaning a jar of germs with boiling water.
Dietitian
A nutrition specialist.
Protein
A nutrient for repairing muscles and tissues.
Neutropenia
Low neutrophils.

08Key points

  • Sealed and clean.
  • Throw out mould.
  • A little at a time.
  • A diet is not a treatment.
  • Talk to a dietitian.

09Frequently asked questions

Is my grandmother's jam OK?

If well sealed and mould-free, often yes; ask your team.

Is sugar-free jam better?

It spoils faster; use it quickly once opened.

Can a special diet cure leukemia?

No. Good nutrition helps you cope with treatment, but it does not cure.

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. Is my grandmother's jam OK?

  2. Is sugar-free jam better?

  3. Can a special diet cure leukemia?

My questions

12Sources

  1. National Cancer Institute. Eating Hints: Before, During, and After Cancer Treatment
  2. ESPEN. ESPEN practical guideline: Clinical Nutrition in cancer (2021)
  3. Leukemia & Lymphoma Society. Food and Nutrition
  4. World Health Organization. Healthy diet fact sheet
  5. American Institute for Cancer Research. Dry Beans and Peas (Legumes)
  6. Harvard T.H. Chan School of Public Health — The Nutrition Source. Nuts for the heart
  7. NHS. 5 A Day: what counts?
  8. American Institute for Cancer Research. Recommendations for Cancer Prevention
  9. MedlinePlus. Vitamin K and warfarin
  10. CDC. Hepatitis A outbreaks linked to frozen berries (food safety)
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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