Vegetable oils - Anaphylaxis Campaign

If you have an allergy to a particular food, you will need to know whether an oil derived from that food is safe for you to eat. This article has been written to help you understand whether there is any allergy risk from edible oils.

Edible oils commonly used in the UK can come from many different types of plants and seeds including rapeseed, sunflower seed, soya, maize, palm, coconut and palm kernel. Oils can also be derived from peanuts, sesame and tree nuts (such as walnut). Regulations state that the source of the vegetable oil used must be indicated on the label of pre-packaged foods.

Refined and unrefined oils

The oilseed industry tells us that when you buy a pre-packed food product containing an edible oil, usually that oil will have been refined. The refining process removes the allergy-causing proteins from the oil to the point where they are barely detectable, even by very sensitive scientific techniques. This suggests fully refined oils are unlikely to pose an allergy risk.

However, in the case of some refined vegetable oils, research is incomplete. Formal safety assessments would need to be carried out by the European Food Safety Authority (EFSA) before they are declared no risk or low risk to people with allergies. The two oils which have been subject of research are soya and peanut.

Some oils are used in their unrefined state in order to provide a particular flavour to the food. An unrefined oil is more likely to cause allergic reactions.

Peanut oil (also known as groundnut oil)

Peanut is a legume and one of the 14 major allergens which need to be declared when they are used as ingredients in a food.

Refined peanut oil is likely to be safe for the vast majority of people with peanut allergy. This was the conclusion of a scientific study carried out in Southampton in 1997. However, the EFSA has said more scientific data is needed before it will consider refined peanut oil to be of no risk to people with peanut allergy. Therefore, refined peanut oil must be declared and highlighted on packaging of pre-packed food.
Unrefined peanut oil is more likely to trigger allergic reactions. According to the oilseed industry, the use of unrefined oil in pre-packed food products is rare but it could be used to give peanut flavour. It must be declared and highlighted on packaging.

We recommend you read our comprehensive fact sheet on peanut and tree nut allergy on our website here.

Soya oil

Soya is one of the 14 major allergens which need to be declared when they are used as ingredients in a food. Soya oil, which may be found in foods including salad dressings, margarine and spreads, has been subject to research and a full risk assessment. Taking into account this research, EFSA declared in 2007 that “it is not very likely” that fully refined soya oils would trigger a severe allergic reaction in susceptible individuals. The Anaphylaxis Campaign understands it is more likely that unrefined soya oil will trigger allergic reactions. Therefore:

Unrefined soya oil must be declared and highlighted (for example, in bold type) within the ingredients when it appears in pre-packed food. It may be declared simply as soya oil.
Fully refined soya oil does not have to be highlighted in the way major allergens must be, but it still needs to be declared as soya oil in line with the regulations stating that the origins of all vegetable oils must be indicated.

We recommend you read our comprehensive fact sheet about soya allergy on our website here.

You can also read the EFSA’s statement about soya oil here.

Other vegetable oils

At the time of publication of this article (January 2018) other oils such as rapeseed, sunflower, maize/corn, and palm kernel have not been subjected to research to test whether refining them makes them safe for people with allergies to those specific foods. We would therefore recommend you speaking to your GP or allergy specialist for advice in your particular case as to whether to avoid these oils.

Coconut oil

Coconut is a member of the palm family and only distantly related to tree nuts. Coconut oil is a cold-pressed oil commonly used in baking and in Asian recipes. It is unrefined and is therefore considered more likely to present an allergy risk for people allergic to coconut.

We recommend you read our knowledgebase article on coconut for more information here.

Sesame oil

Sesame is one of the 14 major allergens which need to be declared when they are used as ingredients in a food. Although further research needs to be conducted, sesame oil is most commonly unrefined and is therefore considered likely to present an allergy risk.

We recommend you read our comprehensive fact sheet on sesame allergy on our website here.

Tree nut oils

Tree nuts are among the 14 major allergens which need to be declared when they are used as ingredients in a pre-packed food. Although further research needs to be conducted, speciality tree nut oils such as walnut oil are unrefined and are therefore considered likely to present an allergy risk.

We recommend you read our comprehensive fact sheet on peanut and tree nut allergy on our website here.

Shea nut oil (shea nut butter)

Shea nut oil is used primarily in confectionery products such as chocolate and is sometimes known as shea nut butter. The information we have on shea nuts is that they appear low risk for most people with nut allergy as the oil is likely to be highly refined.

We recommend you read our knowledgebase article on shea nuts for more information here.

References

Hourihane JO; Bedwani SJ; Dean TP; Warner JO. Randomised, double blind, crossover challenge study of allergenicity of peanut oils in subjects allergic to peanuts. BMJ 1997 Apr 12;314(7087): 1084-8.

Rigby NM, Sancho AI, Salt LJ, Foxall R, Taylor S, Raczynski A, Cochrane SA, Crevel RW, Mills EN (2011). Quantification and partial characterization of the residual protein in fully and partially refined commercial soybean oils. J Agric Food Chem 2011 Mar 9;59(5):1752-9. doi: 10.1021/jf103560h. Epub 2011 Jan 20.

Reviewers

The text of this article has been peer reviewed by Professor John Warner, Professor of Paediatrics Imperial College London; early years theme lead for CLAHRC NW London; and Hon Professor University of Cape Town. Prof Warner was a leading member of the Southampton team that investigated the allergenicity of peanut oil in the late 1990’s.

The text was also checked for accuracy by Angela Bowden of the Seed Crushers and Oil Processors Association (SCOPA), which is the trade association for companies engaged in oilseed extraction and oil/fat processing in the UK. SCOPA part-funded the Southampton research into peanut oil. The text was also checked for accuracy by a senior official with the Food Standards Agency.

Disclaimer

The information provided in this article is given in good faith. Every effort has been 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.

All the information we produce is evidence based or follows expert opinion and is checked by our 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.