This is a simplified description of oleosin proteins – there are more resources available at the bottom of the page for further reading for those who are interested in knowing more.

What are oleosin proteins?

Oleosin proteins are a lesser known allergenic protein found in plants. The proteins are involved in preventing the build up of oil molecules and may have a role in lipid store degradation during plant germination.

Oleosin proteins have been shown to maintain their shape after thermal processing, for example, studies have shown that roasted peanuts (in their shell) had more allergenic oleosin proteins than peanuts which were not heated.

Which foods contain oleosin proteins?

The World Health Organization (WHO) recognises 4 foods as containing oleosin proteins known to cause allergic reactions after consumption of food.

Peanuts, macadamia, quinoa, palm oil, hazelnut, buckwheat, walnut, perilla seeds and sesame seeds all contain oleosin proteins.

What symptoms do they cause?

Allergy to foods containing oleosin proteins have a wide range of symptoms and severity including urticaria (hives or welts), angioedema (swelling under the skin), nausea, abdominal pain, vomiting or breathlessness and anaphylactic shock.

What is the importance of knowing whether a reaction is to oleosin or other allergens?

Multiple allergies are becoming more common and this often leads people to impose a strict restrictive diet on themselves. This can lead to a poor diet lacking in essential nutrients and frustration over a lack of eating options. Knowing which foods are the most likely to be causing your reactions can bring more options back into your diet.

This is why food diaries continue to be an important tool in diagnosis of your allergies – noting the times reactions took place and what medications were taken are a necessary starting point for a proper diagnosis.

There is more information on food diaries HERE.

Science Direct - Oleosin Proteins

Identification of New Allergens in Macadamia Nut and Cross-Reactivity with Other Tree Nuts in a Spanish Cohort, 2024

Sesame eliciting and safe doses in a large sesame allergic population, 2023

Open sesame: Shedding light on an emerging global allergen, 2023

Food Allergens of Plant Origin, 2023

Proteomic study of walnut oleosome and first evidence on oleosin sensitization in allergic patients, 2023

Vegan diet—alternative protein sources as potential allergy risk, 2023

Sesame allergy in children: New insights into diagnosis and management, 2023

Recent advances in diagnosing and managing nut allergies with focus on hazelnuts, walnuts, and cashew nuts, 2022

Oleosin Cor a 15 is a novel allergen for Italian hazelnut allergic children, 2021

Oleosins: A Short Allergy Review, 2020

New Insights Into the Role of Seed Oil Body Proteins in Metabolism and Plant Development, 2019

Genome-wide identification and functional analysis of oleosin genes in Brassica napus L., 2019

Peanut oleosins associated with severe peanut allergy—importance of lipophilic allergens for comprehensive allergy diagnostics, 2017

How relevant is panallergen sensitization in the development of allergies?, 2016

Evolution of Oleosin in Land Plants, 2014

Oleosin Is Bifunctional Enzyme That Has Both Monoacylglycerol Acyltransferase and Phospholipase Activities, 2012

Panallergens and their impact on the allergic patient, 2010

Identification of oleosins as major allergens in sesame seed allergic patients, 2006

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