Table of Contents

f342 Olive Scientific Information Summary Allergen Epidemiology Route of Exposure Clinical Relevance Molecular Aspects Compiled By

Whole Allergen

f342 Olive

f342 Olive Scientific Information

Type:

Whole Allergen

Display Name:

Olive

Route of Exposure:

Ingestion

Family:

Oleaceae

Species:

Olea europaea

Latin Name:

Olea europaea

Other Names:

European olive

Summary

The olive tree is native to the Mediterranean and has been cultivated and utilized by humans for more than 5,000 years. The olive fruit is a global agricultural and dietary resource, particularly in Mediterranean countries. Despite common allergy to its tree pollen and widespread consumption, food allergy to olive fruit is rarely observed. One olive fruit allergen has been described, Ole e 13, a thaumatin-like protein

Allergen

Nature

The olive tree, part of the Oleaceae family, is native to the coastal areas of the Mediterranean and has been cultivated and utilized by humans for more than 5,000 years for its oil, fruit, and wood (1, 2). The olive (Olea Europaea) is a large-pitted, firm fruit, a global agricultural and dietary feature, particularly throughout Mediterranean countries. Olive fruit is also used as the raw material to obtain olive oil (1). The number of olive trees around the world is expected to increase considerably due to the health benefits of the Mediterranean diet, of which olive oil is a staple (3).

Taxonomy

Taxonomic tree of Olive (4)
Domain	Eukaryota
Kingdom	Plantae
Phylum	Tracheophyta
Subphylum	Spermatophytina
Class	Magnoliopsida
Order	Lamiales
Family	Oleaceae
Genus	Olea.

Taxonomic tree of Olive (4)

Epidemiology

Worldwide distribution

Despite common allergy to its tree pollen and widespread consumption, food allergy to olive fruit is rarely observed, with reports being limited to individual cases (1, 5-7).

Route of Exposure

Main

Ingestion (6, 7).

Secondary

Contact (1, 2).

Clinical Relevance

Allergic reactions due to ingestion of olive fruit or oil are rare. One 19-year-old female patient experienced episodic angioedema of the face, neck, hands and tongue 15–30 minutes after olive ingestion. The symptoms abated after 24 hours. No reaction was seen after olive oil ingestion and rhinitis/asthma was not experienced during the pollen season. Skin prick testing (SPT) with three different olive brands gave a positive result (9.7 mm), where 5 controls subjects showed a negative skin test. IgE antibody testing was also positive (7).

Another case study of a 28-year-old man with a 3-year history of persistent rhinitis and seasonal exacerbation reported palatal itching after ingestion and generalized urticaria consistently following olive fruit consumption. These symptoms subsided spontaneously within a few hours. SPT was positive to olive-fruit extract, fresh green and black olives, and olive pollen. Specific IgE was also positive for olive fruit and olive pollen (6).

A further case study of a 21-year-old woman with a history of house dust mite allergic rhinitis and asthma reported three episodes of oropharynx and palms itching, cough and dyspnea a few minutes after eating a snack with onion, gherkin, red pepper and olive. These symptoms subsided with beta-2-agonists and antihistamines after a few hours. SPT were positive to olive fruit (raw material), olive oil and mites, and were negative to pollens (including olive pollen). Five control subjects showed a negative test with olive fruit. Total IgE was positive for mites and negative to pollens and foods (1).

Atopic Dermatitis

Olive, olive oil and olive wood have also been implicated in allergic contact urticaria and dermatitis, in these cases, patients appear to be sensitized by topical treatments. Reports of occupational allergic contact dermatitis have been described in pedicurist, masseur, pizza maker and beautician (1, 2).

Molecular Aspects

Allergenic molecules

Table adapted from Allergome.org (8).

Allergen	Type	Mass (kDa)
Ole e 13 [fruit]	Thaumatin	24.7

Allergen	Type	Mass (kDa)

One thaumatin-like olive fruit allergen has been described, Ole e 13 (2). Overall though, the causative allergens of olive fruit allergy are not well-known (1, 2). Immunoblotting of an allergic patient’s serum revealed different IgE-binding bands with molecular weights of 14.4, 20.1, 30 and 45, these were detected in the lipid-soluble fraction isolated from olive fruit. This suggests that an IgE-mediated olive fruit allergy may be caused by lipoproteins (1).

Cross-reactivity

There have been reports of olive fruit allergy after pollen immunotherapy, suggesting the presence of a common allergen structure both in olive pollen and in olive fruit (2, 6).

Compiled By

Author: RubyDuke Communications

Reviewer: Dr. Christian Fischer

Last reviewed: April 2022

References

Alvarez-Eire MG, Pineda de la Losa F, Varela Losada S, González de la Cuesta C, Ricardo Palacios R. Anaphylaxis to olive fruit due to lipoprotein sensitization. Allergologia et Immunopathologia. 2012;40(3):198-200.
Esteve C, Montealegre C, Marina ML, García MC. Analysis of olive allergens. Talanta. 2012;92:1-14.
Calzada D, Cremades-Jimeno L, López-Ramos M, Cárdaba B. Peptide Allergen Immunotherapy: A New Perspective in Olive-Pollen Allergy. Pharmaceutics. 2021;13(7):1007.
ITIS. Olea europaea 2021 [cited 2022 13.01.22]. Available from: https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=32990#null.
Oeo-Santos C, Navas A, Benedé S, Ruíz-León B, Díaz-Perales A, Vogel L, et al. New insights into the sensitization to nonspecific lipid transfer proteins from pollen and food: New role of allergen Ole e 7. Allergy. 2020;75(4):798-807.
Unsel M, Ardeniz O, Mete N, Ersoy R, Sin AZ, Gulbahar O, et al. Food allergy due to olive. J Investig Allergol Clin Immunol. 2009;19(6):497-9.
Azofra J. Olive allergy. Allergy. 2004;59(5):559.
allergome.org. Olea europaea 2021 [cited 2022 13.01.22]. Available from: http://www.allergome.org/script/search_step2.php.