The following information is intended to help people with allergy to cashew nuts to manage their condition successfully.
Cashew nut allergens are highly potent, and for some people these reactions have the potential to be severe and even life-threatening (a condition known as anaphylaxis). The prevalence of cashew nut allergy is increasing, especially in children. Increased consumption of cashew nuts and a change in eating and cooking habits may be responsible. If you know or believe you are allergic to cashews, it is important to visit your GP and seek a referral to an allergy clinic.
How do I reduce risks?
When buying pre-packed food products, you should find cashew nuts straightforward to avoid so long as you read food labels carefully. All pre-packaged food sold within the UK must declare and highlight the presence, in an ingredient list, of major allergens including of cashew nuts, even if they appear in small quantities.
The food allergen labelling laws that cover pre-packed food now also apply to the catering sector. When eating out or buying takeaway food, food businesses are required to provide information on major allergenic ingredients (including cashews). This information can be provided in writing and/or orally. If information is provided orally, the food business will need to ensure that there is some sort of written signage that is clearly visible, to indicate that allergen information is available from a member of staff. Systems should also be in place to ensure that, if requested, the information given orally is supported in a recorded form (in writing for example) to ensure consistency and accuracy.
Foods where cashew nuts are sometimes used include pesto sauce (which has traditionally been made from pine nuts) muesli and cakes.
Cashews are used in cooking in the Far East and in the Indian sub-continent and may be found in ethnic food from those areas. We advise people with severe nut allergy to avoid Asian restaurants (such as Indian, Chinese or Thai) because nuts are so commonly used as ingredients, and there is also a risk of cross-contamination. Cashews and pistachios can be used in baking, especially in Eastern pastries and in confectionery items, sweets, ice creams and chocolates. Cashew nut butter is produced and is the equivalent of peanut butter. It is found in supermarkets as well as whole food shops.
Avoiding other nuts
The cashew nut and the pistachio nut are botanically related. Studies have found that people allergic to cashew are almost always allergic to pistachio as well. This is a process known as cross-reactivity – in which the proteins in one food are similar in structure to those in another food.
People allergic to cashew can also be allergic to other nuts. So is it best to avoid all nuts if you are allergic to one or two of them?
Some allergy experts would indeed advise that total avoidance is best in order to play safe. But others disagree. One review states: “In peanut or tree nut allergic children, introduction of specific nuts to which the child is not allergic may improve quality of life and should be considered in patients with multiple foods allergies, vegan or ethnic-specific diets, in whom nuts are an important source of protein.”
Our advice is that it depends what allergy tests you have had. If you have been tested for specific nuts, your doctor or allergist will be able to advise whether it is possible to include certain nuts in your diet. If you do eat specific nuts, it is usually advisable to do so at home so you can better control any risk of cross-contamination. Eating nuts from the shells can avoid the risk of cross-contamination from other types of nut.
If you have not been tested for specific nuts, then we believe in playing safe – avoiding all nuts – until you are able to be tested.
Oils and derivatives
As far as we are aware, the oil derived from cashew nuts is not used in foods made and sold in the UK. However it is best to be on your guard in case this should change. Derivatives of cashew nuts are permitted in cosmetics and toiletries including foundation make-up, shampoos, lotions and scalp creams. The term to watch out for in the label is the Latin name Anacardium occidentale.
Click here to read detailed information in our factsheets on anaphylaxis and its treatment, adrenaline.
The content of this fact sheet has been peer-reviewed by Dr Andy Clark, Consultant in Paediatric Allergy, Cambridge University Hospitals.
All the information we produce is evidence based or follows expert opinion and is checked by our expert Clinical and research reviewers. If you wish to know the sources we used in producing any of our information products, please let us know, and we will gladly supply details.
The information provided in this knowledgebase article is given in good faith. Every effort is taken to ensure accuracy. All patients are different, and specific cases need specific advice. There is no substitute for good medical advice provided by a medical professional.
Publication date: November 2018
Review date: November 2021