Type:
Whole Allergen
Whole Allergen
Whole Allergen
Sweet chestnut
f299
Fagaceae
Castanea sativa
Ingestion
Castanea sativa
Edible chestnut, European chestnut, Spanish chestnut, chestnut, marron
Sweet chestnut, a member of the Fagaceae family, is commonly consumed raw or roasted due to its rich nutritional value. Allergy to chestnuts has been widely reported in latex-fruit syndrome, whereas reports of primary chestnut food allergy are rare. The main chestnut allergens that have been identified include Cas s 5, Cas s 8 and Cas s 9.
The sweet chestnut tree was a species originally found only south of the Alps but was spread by the Romans in Western Europe and Slovakia. It is now widespread throughout the Mediterranean, Asia Minor and the Caucasus (1). Sweet chestnut also known as European chestnut or simply chestnut, is edible and belongs to the botanical family of Fagaceae that are mainly produced in China, Bolivia and Turkey. Sweet chestnut is nutritious and contains dietary fibers, minerals, essential fatty acids, vitamins, essential amino acids and antioxidants. It is commonly consumed raw or in a roasted form, as well as ground, in the form of chestnut flour (2).
Taxonomic tree of Sweet Chestnut (3) |
|
Domain |
Eukaryota |
Kingdom |
Plantae |
Phylum |
Tracheophyta |
Subphylum |
Spermatophytina |
Class |
Magnoliopsida |
Order |
Fagales |
Family |
Fagaceae |
Genus |
Castanea Mill. |
In Korea, fresh and boiled chestnuts are commonly eaten and account for the third most prevalent food allergen and most prevalent tree nut allergen in pediatric and adult allergy patients (4). In one study, the sensitization rate to homemade chestnut extract was 3.2% in Korean self-described adult allergy patients (5).
Allergy to chestnuts has been widely reported in latex-fruit syndrome although reports of primary chestnut food allergy are extremely rare (6). Despite high sensitization rates to chestnut, indications about primary allergy to chestnut is through case studies. Out of 22 chestnut-allergic patients (including both primary allergic and cross-reactive patients with latex-fruit syndrome) 8 had experienced severe anaphylactic episodes upon chestnut ingestion (7).
Approximately 40–50 % of patients with latex allergy show hypersensitivity to freshly consumed fruits or nuts, mainly avocado, banana, chestnut, and kiwi, clinically referred to as latex-fruit syndrome (8). Chestnut accounts for around 24% of cases linked to this syndrome, after banana (28%) and avocado (28%) (9).
One case of oral allergy syndrome has been reported in which chestnut was the causative food allergen (10).
Table adapted from Allergome.org (11).
Allergen |
Type |
Mass (kDa) |
Cas s 1 |
PR-10 protein |
22 |
Cas s 2 |
Profilin |
14 |
Cas s 5 |
Chitinase |
32 |
Cas s 8 |
Lipid transfer protein |
9 |
Cas s 9 |
Heat shock protein |
17.5 |
Cas s TLP |
Thaumatin |
25 |
The main chestnut allergens identified include Cas s 5 (a class I chitinase), Cas s 8 (a lipid transfer protein), Cas s 9 (a cytosolic class I small heat shock protein) and Cas s TLP (a thaumatin-like protein) (6).
Patients with primary chestnut allergy appear to react to Cas s 8 (lipid transfer proteins), whereas patients with associated latex hypersensitivity react to Cas s 5 (class I chitinases) (8).
Latex-fruit syndrome is a cross-reactive condition where primary sensitized patients to latex react to fruits or nuts including chestnuts (8). Allergy to latex usually precedes food allergy, although this is not always the case. In latex-fruit syndrome, symptoms are often severe after ingestion of these foods (9, 12).
A study in patients with primary chestnut allergy (with no latex allergy) were sensitized to mugwort pollen (Cas s 8 reactivity to Art v 3) and peach (Cas s 8 reactivity to Pru p 3) (8).
Author: RubyDuke Communications
Reviewer: Dr.Michael Thorpe
Last reviewed: May 2022