Barley is a grain in the Poaceae
family of plants. Other plants in this family includes corn, wheat, durum wheat, oat, rice and rye.
5 key food allergens have been identified in barley and an additional airway allergen, so is important for those sensitised to barley pollen.
Hor v 12 is a profilin protein
, these are panallergens which have been found to cause allergies in many foods.
Hor v 20 is a gamma hordein and is the allergen most commonly linked to cross reactivity with other grains. Hordeins belong to the prolamin group of proteins which also includes gliadin, secalin, zein, kafirin and avenin. Reactions to this group of proteins is strongly linked to coeliac disease.
The other allergens are alpha and beta amylases - these are proteins also found in wheat
. Amylases in plants are used to break down stored starches to aid in plant growth.
Malted or malt barley is barley which is left to germinate and then the process is stopped quickly by heating. This process turns the starches in the plant to sugars which can then be used to make vinegars, whiskeys and beer. Malting barley does not neccessarily breakdown any allergenic proteins, in fact the amylase proteins in barley are increased by the process.
Barley is a high FODMAP food. FODMAP
stands for F
olyols. Foods high in FODMAPs can cause symptoms of food intolerance, affecting the gastro intestinal system and this can be mistaken for a true IgE food allergy.
Barley is low in salicylates. Salicylates
have the potential to cause gastrointestinal food intolerance symptoms in people who are sensitive to salicylates.
Barley contains horcolin, a lectin
with the potential to cause food intolerance. Cooking foods with lectins makes them more digestible and can reduce the symptoms of food intolerance.
You can read more about Food Intolerances
on the dedicated Food Intolerance Page.
As barley contains a gamma hordein it is commonly linked to exercise induced anaphylaxis
, more specifically to wheat dependent exercise induced anaphylaxis. This is because the gamma hordein is similar in structure to omega-5 gliadin's found in wheat.
Coeliac disease (celiac disease is the American spelling) is not an allergic condition, but is triggered by gluten
found in wheat and there are similarly shaped proteins in barley to which sensitive individuals may react.
Allergy to wheat is sometimes linked to Celery-Mugwort-Spice Syndrome
as the sensitising allergen is a profilin protein called Art v 4, these proteins are also sometimes also called Bet v 2 proteins.
There is a link between wheat and Latex Food Syndrome
. The plant involved in latex allergy Hevea brasiliensis
, the rubber tree plant, has an allergen called Hev b 8 which is a profilin protein. Those very sensitised to latex may have a contact allergic reaction from other foods or plants containing profilin proteins, there is less evidence of this than sensitisation to other latex linked proteins like hevein and chitinases.
Barley is in the Poales
order of foods, so there may be some cross reactivity with other foods in the group such as wheat, rye and maize. Read more about Grain Allergens
Profilin proteins are also found in pineapple, celery, peanut, chilli, watermelon, orange, hazelnut, carrot, strawberry, soya, barley, walnut, lychee, lupin, apple, banana, dates, cherry, kiwi, peach, pear, mustard, tomato, aubergine and wheat.
Note that the food lists here are not exhaustive, the most up to date information is on the Cross Reactivity Tool.
Science Direct - Hordein
Allergen Encyclopedia - Barley
Allergy information for: Barley (Hordeum vulgare)
ACAAI - Wheat & Gluten Allergy
Coeliac UK - Barley Malt Vinegar
Coeliac UK - About Gluten and Grains
Healthline - FODMAP Foods
Articles and Journals
IgE-Dependent Allergy in Patients with Celiac Disease: A Systematic Review, 2023
Cross-reactive epitopes and their role in food allergy, 2023
Clinical cross-reactivity of wheat and barley in children with wheat allergy, 2022
Cross-reactivity of each fraction among cereals in children with wheat allergy, 2022
The clinical cross-reactivity and immunological cross-antigenicity of wheat and barley, 2022
Beer and Allergens, 2021
Clinical and Laboratory Findings of Barley Allergy in Korean Children: a Single Hospital Based Retrospective Study, 2020
The barley lectin, horcolin, binds high-mannose glycans in a multivalent fashion, enabling high-affinity, specific inhibition of cellular HIV infection, 2020
Rye gamma-70 and gamma-35 secalins and barley gamma-3 hordein cross-react with omega-5 gliadin, a major allergen in wheat-dependent, exercise-induced anaphylaxis, 2001
Beer, Cider, and Wine Allergy, 2017
Beer-induced anaphylaxis: identification of allergens, 1999
Pollen allergen homologues in barley and other crop species, 1995
A barley flour inhibitor of insect alpha-amylase is a major allergen associated with baker's asthma disease, 1989
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