Pine nuts are the edible seeds collected from pine trees cultivated in Europe, the USA and Asia. They are sold in health food stores and can occasionally be found as ingredients in pre-packed food products such as pesto sauce.
Although allergy to pine nuts is uncommon, there are numerous reports in the medical literature showing that reactions do occur and that these can be severe. It is common for people with pine nut allergy to have no other food allergies.
If you are allergic to pine nuts, or think you may be allergic, this article will provide you with valuable information.
Any adverse symptoms to pine nuts should be reported to your GP. If an allergy is suspected, it is likely that you will be referred to an allergy clinic.
What is a food allergy?
Food allergy occurs when a person’s immune system reacts inappropriately to a food. The first stage of the process is called sensitisation – when the immune system’s “memory” registers the food as a threat. Antibodies to that food are produced, and at a subsequent encounter, these antibodies may connect with the food’s proteins and trigger the release of certain substances in the body, such as histamine. This results in an allergic reaction.
Symptoms of a food allergy
The symptoms of a food allergy can come on rapidly. These may include nettle rash (otherwise known as hives or urticaria) anywhere on the body, or a tingling or itchy feeling in the mouth.
More serious symptoms of a food allergy may include:
- Swelling in the throat and/or mouth
- Difficulty breathing
- Wheeze or asthma
- Severe abdominal pain and recurrent vomiting
The term for this more serious form of allergy is anaphylaxis. In extreme cases there could be a dramatic fall in blood pressure (anaphylactic shock). The person may become weak and floppy and may have a sense of something terrible happening. This may lead to collapse and unconsciousness. On rare occasions, death from a food allergy can occur.
Click here for more details about anaphylaxis and its treatment. This will help you understand what to do in an emergency.
If you are allergic to pine nuts, must you avoid other nuts?
Pine nuts are in a different botanical category to tree nuts (such as walnuts, Brazils and cashews) and researchers point out that the overwhelming majority of people with pine nut allergy can tolerate these other nuts, and vice versa (Cabanillas and Novak, 2015). So if you are allergic to pine nuts, it is highly unlikely that you need to avoid other nuts and seeds but discuss this with your doctor if you have any concerns.
Where are pine nuts used?
As stated above, pine nuts are often used in pesto sauce. They can also be used wherever tree nuts or peanuts are used, so they might be found in cakes, bread, biscuits, confectionery and ice cream.
They are sold in health food stores as well as in supermarkets and are often eaten as a snack. They are much more common in the foods of countries where they are harvested commercially and so they are used in savoury and sweet dishes from, in particular, Spain, Italy and Morocco. Pine nuts are widely used in the USA.
The use of pine nut oil is rare. It is golden coloured and can be used for making salad dressings and drizzling on to dried or grilled meats.
The pine nut is known by a variety of other names including pine kernels pinon, Indian nut, pignoli and pignolia.
‘Pine mouth’ syndrome
People have reported experiencing a metallic or bitter taste within 48 hours of eating pine nuts. This can last for up to two weeks. Doctors are uncertain what causes pine mouth syndrome, but do not believe it is harmful to health. It is not thought to be an allergic reaction.
This article has been reviewed by Dr Gary Stiefel, Consultant in Paediatric Allergy, University Hospitals of Leicester NHS Trust. He has no conflicts of interest to report.
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