Peanut allergens: what they are and how they behave
What it found
Peanut contains 16 officially recognised allergens, and which ones cause reactions varies by region.
Roasting peanuts can increase their allergenicity, while boiling can reduce it.
What they found
Studies in people
Regional differences
The pattern of sensitization to peanut allergens varies among populations in different geographical regions. In the USA, Ara h 1, Ara h 2, and Ara h 3 are the main elicitors of allergic reactions, while Spanish patients are more often sensitized to Ara h 9.
Diagnosis with Ara h 2
The major peanut allergen Ara h 2 is associated with the severity of symptoms of peanut allergy. Specific IgE to Ara h 2 could be used as a good predictor of suspected peanut allergy in children and adults.
Clinical trials
In a sublingual immunotherapy study, 14 of 20 subjects receiving peanut SLIT were responders compared to 3 of 20 subjects receiving placebo. In the LEAP study, only 1.9% of children in the consumption group developed peanut allergy at 60 months, whereas 13.7% developed peanut allergy in the avoidance group.
Animal and lab studies
Vaccine candidates
Recombinant hypoallergenic variants of Ara h 1, Ara h 2 and Ara h 3 have been produced with reduced IgE-binding capacity. In a mouse model, treatment with modified peanut allergens decreased peanut-specific IgE and histamine levels and offered protection from anaphylaxis.
Studies in people and animals
Roasting and boiling
Roasting peanuts was shown to increase peanut allergenicity and the IgE-binding capacity of peanut allergens. Boiling decreases the IgE binding capacity of Ara h 1, Ara h 2, and Ara h 3 compared to roasting.
Other findings
Allergens recognised
Sixteen proteins in peanuts are officially recognised as allergens. These belong to seven protein families, including seed storage proteins, profilins, and defensins.
What the authors conclude
“Peanut allergy is one of the most severe food allergies which usually is not outgrown.”
Also in their conclusions
- They state that the early introduction of peanuts in the diet of children at high risk is beneficial for reducing the frequency of the development of peanut allergy.
- They note that strict avoidance of the culprit food is the only available option for treatment at present.
- They advise that the allergenic characteristics and immunological properties of the peanut oleosins, defensins, and nsLTPs will have to be determined in broader studies.
How it was done
Peanut allergy is one of the most severe food allergies and usually is not outgrown. Symptoms can be triggered by tiny amounts of allergens and even manifest as severe anaphylaxis.
The authors reviewed the scientific literature on peanut allergens, covering their sequences, structures, biological functions, how they are purified and produced, the effects of thermal processing, their use in diagnosis, and clinical trials of treatments.
What it can’t tell you
- This is a review of many different studies, so it cannot show cause and effect for any single finding.
- Animal and lab results cannot show what happens in people.
- The review cannot say whether any particular peanut product is safe for someone with a peanut allergy.
Who paid
- Funding
- Funded by Austrian Science Fund FWF (from the PubMed record).
- Authors work at
- Medical University of Vienna, Austria
The paper
- Title
- Peanut allergens
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Palladino C, Breiteneder H (2018). Peanut allergens. Molecular immunology. doi:10.1016/j.molimm.2018.04.005Free full textPubMed 29680589DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error