Allergies to seeds and foods with “nuts” in the name

This factsheet includes information about:

  • Pine nuts
  • Chestnuts
  • Nutmeg
  • Coconut
  • Shea nuts

 

Allergies to these are unusual and they are not included in the ‘top 14’ major food allergens.

These seeds and “nuts” belong to several different plant families that are not the same as tree nut or peanut plant families. They don’t contain the same proteins that cause allergic reactions in people with peanut or tree nut allergies. So, if you are allergic to one of the foods on this page, that does not necessarily mean you will be allergic to tree nuts or peanuts, and vice versa. You only need to avoid the foods you’re allergic to. Occasionally, there are exceptions so discuss all this with your allergy specialist if you are unsure.

What is a food allergy?

Food allergy occurs when the body’s immune system wrongly identifies a food as a threat. When this happens, the body releases chemicals, such as histamine, in response. It is the release of these chemicals that causes the allergic symptoms. Allergies to seeds and foods with “nuts” in the name are types of food allergy.

Seeds and foods with "nuts" in the name factsheet

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What are the symptoms of a food allergy?

The symptoms of a food allergy usually come on quickly, within minutes of eating the food.

Mild to moderate symptoms may include:

  • a red raised rash (known as hives or urticaria) anywhere on the body
  • a tingling or itchy feeling in the mouth
  • swelling of lips, face or eyes
  • stomach pain or vomiting.

More serious symptoms

The term for this more serious reaction is anaphylaxis (pronounced anna-fill-axis).

Most healthcare professionals consider an allergic reaction to be anaphylaxis when it involves difficulty breathing or affects the heart rhythm or blood pressure. Any one or more of the ABC symptoms above may be present.

In extreme cases there could be a dramatic fall in blood pressure. The person may become weak and floppy and may have a sense of something terrible happening. This may lead to collapse and loss of consciousness and, on rare occasions, can be fatal.

More serious symptoms are often referred to as the ABC symptoms and can include:
  • right_arrow_orange_icon AIRWAY - swelling in the throat, tongue or upper airways (tightening of the throat, hoarse voice, difficulty swallowing).
  • right_arrow_orange_icon BREATHING - sudden onset wheezing, breathing difficulty, noisy breathing.
  • right_arrow_orange_icon CIRCULATION - dizziness, feeling faint, sudden sleepiness, tiredness, confusion, pale clammy skin, loss of consciousness.

Getting a diagnosis

If you think you may be allergic to one of these seeds or other “nuts”, see your GP who can refer you to a specialist allergy clinic if needed. They can find a clinic in your area from the British Society for Allergy and Clinical Immunology (BSACI).

It’s important to get a referral even if your symptoms were mild because it can be hard to tell if future allergic reactions could be more serious.

Once you get a referral, the consultant will discuss your medical history and symptoms with you. They might suggest skin prick tests, blood tests, and food challenge tests to help diagnose the allergy and work out how serious it may be.

What can mean you’re at higher risk?

Some clues that you might be at higher risk of more serious reactions are:

  • you have already had a serious reaction, with any of the ‘ABC’ symptoms
  • you have asthma, especially if it is not well controlled
  • you have reacted to a tiny amount of the food.

 

If you have asthma and it is not well controlled, this could make an allergic reaction worse. Make sure you discuss this with your GP or allergy specialist and take any prescribed medicines.

Treating symptoms

If you have mild allergic symptoms, you may be prescribed antihistamine medicine that you take by mouth. If you are at risk of anaphylaxis, you may be prescribed adrenaline to use in an emergency.

Adrenaline comes in pre-loaded adrenaline auto-injectors (AAIs) that are designed to be easy to use. Make sure you know how and when to use them. Ask your healthcare professional to show you how to use your specific brand of AAI. You can also find help on the manufacturer’s website and get a free trainer device to practise with.

You must carry two with you at all times, as you may need to use a second one if your symptoms don’t improve after five minutes or get worse.

Adrenaline auto-injectors

The adrenaline auto-injectors prescribed in the UK are:

Avoiding seeds and foods with “nuts” in the name

Once you have been diagnosed with an allergy to a seed or other “nut”, you will need to avoid it and foods that contain it.

Read the ingredient lists on food packets carefully every time you shop. These foods are not included in the list of top 14 major food allergens in the UK. This means they will normally be listed as an ingredient on the label, but they won’t be highlighted, in bold for example.

Read the ingredient list every time you buy a product as manufacturers change their recipes often.

When eating out

Restaurants, cafes, hotels, takeaways and other catering businesses are not required by law to provide information about ingredients that are not included in the top 14 major food allergens. This means you will need to ask staff directly if the food you’d like to buy contains the food you’re allergic to and if there is a risk of cross-contamination. Let them know that even small quantities can cause a reaction and don’t be afraid to ask staff to check with the chef.

Pine nuts

Pine nuts are the edible seeds of pine trees grown in Europe, the USA and Asia. Allergy to pine nuts is uncommon, but if you think you have had a reaction to pine nuts, visit your GP.

Pine nuts are not in the same family as any other tree nuts or peanuts, so if you are allergic to pine nuts that doesn’t automatically mean you will be allergic to other nuts and vice versa.

  • Which foods contain pine nuts?

    Pine nuts are used as ingredients in lots of different foods.

    They are often found in pesto sauce and packets of mixed seeds.

    They are sometimes used in:

    • sandwiches
    • cakes
    • bread
    • cereals
    • salads
    • pizzas
    • biscuits
    • confectionery
    • ice cream.

    Pine nuts can sometimes also turn up in products where you don’t expect them. They have been seen as ingredients in a lentil and mint lamb leg joint, a butternut squash rolled pork loin, vegan chocolate tortes and a Christmas pudding.

  • Pine nut oil

    If you are allergic to pine nuts, avoid oil made from them as well. Pine nut oil is rarely used but can be used for making salad dressings and drizzling on to dried or grilled meats.

  • “Nut free” does not mean “pine nut free”

    The phrase “nut free” does not mean there are no pine nuts included because pine nuts are in a different plant family to tree nuts and peanuts.

  • Other names to look out for

    Pine nuts are known by a variety of names including pine kernels, pinon, Indian nut, pignoli and pignolia.

  • ‘Pine mouth’ syndrome

    Some people have a metallic or bitter taste that comes on within 48 hours of eating pine nuts and can last for up to two weeks. Doctors are uncertain what causes pine mouth syndrome but don’t believe it is harmful. It is not thought to be an allergic reaction.

Sweet chestnuts

Sweet chestnuts are the edible nuts of sweet chestnut trees which grow in the UK, Europe, Western Asia and North Africa. Sweet chestnuts are usually known simply as chestnuts.

Allergy to chestnuts is uncommon in the UK and there is not much information about how serious the reactions may be

Chestnuts don’t contain the same proteins that cause allergic reactions in people with peanut or tree nut allergies. So, if you are allergic to chestnuts that does not necessarily mean you will be allergic to tree nuts or peanuts, and vice versa.

Most people with a chestnut allergy have an allergy to other fruits and vegetables. This is because of “cross-reactivity” – where the proteins in different fruits and veg are similar to the proteins in chestnuts.

In people with a serious allergy to chestnuts, which is rare, the protein that causes the reaction is likely to be one of the lipid transfer proteins (LTPs).

Read more in our LTP allergy factsheet.

  • The link with latex – Latex Food Syndrome

    Many people who react to chestnuts also have an allergy to natural rubber latex (NRL). Some of the proteins in latex have a similar structure to those in certain fruit and vegetables, including chestnut. Others include avocado, banana, kiwifruit, peach, tomato, potato and sweet pepper.

    When people are allergic to both latex and one or more of these foods, the condition is known as Latex Food Syndrome.

    For more information see our Latex allergy factsheet

  • Which foods contain chestnuts?

    Chestnuts are often eaten roasted. They can be used to make stuffing and at Christmas are often served with Brussels sprouts. They are used in baking and can be bought canned, pureed or as chestnut flour. They are sometimes included in game or rich winter casseroles.

    Banon is a cheese made in France from unpasteurised goats’ milk, wrapped in brown chestnut leaves and tied with raffia. If you are allergic to chestnuts, it’s possible that you might react to the leaves.

  • What about water chestnuts?

    Water chestnuts are from a different plant family to sweet chestnuts. Water chestnuts may be used as flour, sometimes known as Singoda flour, and used to make batter for deep frying in some multi-cultural recipes. People who are allergic to sweet chestnuts can normally eat water chestnuts without a problem.

  • What about Horse chestnuts (conkers)?

    Horse chestnuts are not in the same plant family as sweet chestnuts and there is no evidence they will cause an allergic reaction.

    It is possible to have an airborne allergy to horse chestnut pollen which could cause contact dermatitis (a skin rash) when handling horse chestnuts. This is not related to chestnut allergy.

Nutmeg

Nutmeg is a spice made from the seeds of the Nutmeg tree which grows in tropical countries including Indonesia, India and Sri Lanka. It’s used to flavour many foods including bread, hot cross buns, haggis, multi-cultural dishes, toppings on milk pudding and eggnog.

It is possible to be allergic to nutmeg, but this is very rare and there is not much information available about how serious reactions may be. If you think you have had an allergic reaction to nutmeg, visit your GP.

If you have a peanut or tree nut allergy, there’s no evidence that you will be at risk of a nutmeg allergy as they belong to different plant families.

Coconut

Coconuts are not nuts but are ‘drupes’, which is a type of fruit with a hard stony covering. They grow on coconut trees, which are members of the Palm family, in coastal tropical regions. Allergy to coconut is thought to be rare in the UK, although there is very little information available.

In the past, some people were mistakenly told that they were allergic to coconut due to the results of an allergy blood test called ImmunoCAP fx1 Mixed Nuts which is used by GPs in some areas. It checks for peanut, hazelnut, brazil nut, almond and coconut antibodies, but if the test is positive, it does not mean that you are allergic to all of them. You’ll need a separate test to find out which food or foods you are allergic to.

If you have been told you are allergic to coconut but are not sure if a separate coconut allergy test was done, or if you are allergic to one or more other nuts and don’t know if you are allergic to coconut, ask your GP to arrange for a coconut allergy test.

  • Which foods contain coconut?

    Coconut can be bought fresh or processed as coconut milk, coconut water, creamed coconut or desiccated coconut. It can be used as an ingredient in baking, ice cream, breakfast cereals, confectionary and curries.

    Many products are made with coconut, here’s just a few examples:

    • Macaroons
    • Bounty chocolate bar
    • Vegan cheese
    • Malibu rum
    • Cocktails such as Pina Coladas
    • Fruit juices
  • Coconut oil

    Coconut oil is usually a cold-pressed, unrefined oil used for baking and cooking. Because it is unrefined, it contains the proteins that cause allergic reactions, so you will need to avoid cold-pressed coconut oil. It’s not known if fully refined coconut oil would cause a reaction so its best to avoid it if you have a coconut allergy.

    Coconut oil and extracts are used in some cosmetics and toiletries, especially in soaps, hand gels, shampoos and hair conditioners. How likely these products are to cause allergic reactions is not known.

    When you read the ingredients lists of cosmetics, you will see common food-based ingredients given a Latin name. The Latin name for coconut is Cocus nucifera.

    Read more in our Cosmetics, personal care products and medicines factsheet.

Shea nuts

Shea nuts are the seeds of the fruit of Shea trees which grow mainly in Africa. The seeds are used to make shea nut butter, sometimes known as shea nut oil, which is a refined product.  It is used in cosmetics products such as soaps, shampoos, and moisturisers as well as some foods including chocolate, sweets and ice cream.

Shea nut butter is not thought to cause allergic reactions, including in people with peanut or tree nut allergies. No cases of allergy to shea nut or shea nut butter have ever been reported.

Refined shea nut butter does not contain any detectable proteins and it is the protein in a food that causes allergic reactions.

Key messages

  • If you or your child have allergic symptoms after eating seeds or any of these foods with “nuts” in the name, visit your GP.
  • These seeds and foods with “nuts” in the name are not in the same plant families as peanuts or tree nuts.
  • Always be guided by your allergy specialist on which foods to avoid.
  • If you are at higher risk of anaphylaxis, you may be prescribed adrenaline auto-injectors. Carry two with you at all times.

Seeds and foods with "nuts" in the name factsheet

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