Celery (Apeum graveolens) grows wild in Europe, around the Mediterranean and in Asia west of the Himalayas. It is also widely cultivated as a vegetable, which is consumed raw, cooked or dried in spice mixtures. Celery is grown for its wide, fleshy stalks as well as its large, edible tuber, known as celeriac. Celery stalks are commonly used in soups, stews and in salads, and celeriac is used mainly as a cooked vegetable, but is becoming increasingly popular grated into raw salads. Celery is also grown for its seeds, which contain a valuable essential oil used in the flavouring, perfumery and pharmaceutical industries. Celery seeds are used as a flavouring, either whole or ground into a powder, which is mixed with salt to form celery salt. Celery salt is also sometimes made from celeriac.
Celery is one of the most common foods to cause oral allergy syndrome in adults in countries such as Switzerland, Germany and France.
Allergy to celery root (celeriac) is more common than allergy to celery stalks. The principal allergen in celery is designated Api g1, and it appears to be resistant to heat, so that its allergenicity is retained even after extensive thermal treatment. Cooking, therefore, does not reduce the allergenicity of celery or its products. Celery spice and raw celery are equally allergenic.
Allergy to celery is often associated with allergy to tree and grass pollen. Individuals who develop allergy to birch pollen tend to be allergic to the birch pollen allergen, designated Bet v 1. Proteins related to Bet v 1 are found in other plants and in the edible tissues of a number of fruits and vegetables, including celery. When people who have a Bet v 1-type allergy eat certain fruits and vegetables, such as celery, they often experience a reaction confined to the mouth, known as oral allergy syndrome. Because allergy to celery is frequently associated with birch and/or mugwort pollinosis, the term birch-mugwort-celery-syndrome has been established.
Allergy to other vegetables, such as carrots and bell peppers, is also associated with celery allergy, as is allergy to certain other members of the Apiaceae family, such as parsley, aniseed, cumin and coriander.
Allergy to celery is particularly common in European countries, such as Switzerland, Germany and France. It is the most common pollen-related food allergy in Switzerland, where about 40% of patients with food allergy are allergic to celery root, and severe anaphylactic reactions have been observed. In France, about 30% of severe allergic reactions to food were thought to be caused by celery.
There is evidence that birch pollen and celery allergy are highly related in Central Europe, while in Southern Europe, celery allergy is most frequently related to mugwort pollen.
Effects on health
The most common symptom associated with celery allergy is the oral allergy syndrome. During challenge testing with celery, 50% of patients developed local reactions in the mouth and 50% developed systemic reactions. Other symptoms include:
The symptoms associated with celery allergy are frequently more severe compared with allergic reactions associated with other fresh vegetables.
The threshold dose needed to elicit an allergic reaction has not yet been established; however, in a study of patients undergoing oral challenge with celery, almost a half developed symptoms of allergy at a dose of 700 mg.
Management of celery allergy
Avoidance of celery, celeriac and all foods containing celery is the best way to manage the condition. The main difficulty arises in the extensive use of celery extracts in spices. The dried powder from celeriac is used as a flavouring ingredient in numerous processed foods, such as soups, stews, salad dressings and spice mixtures. Care should be taken when reading food labels. Owing to its high allergenic potential, celery has now been included as one of the major allergens that have to be labelled in pre-packed foods sold in the EU. This is not currently the case in the United States.
Sources of Further Information
Ballmer-Weber B. et al.
Allergen Data Collection: Celery (Apium graveolens)
Internet Symposium on food allergens, 2000, 2 (3), 145-167
Ballmer-Weber B. et al
Celery allergy confirmed by double-blind, placebo-controlled food challenge: A clinical study in 32 subjects with a history of adverse reactions to celery root.
Journal of Allergy and Clinical Immunology, 2000, 106 (2), 373-378
On the web
Internet Symposium on Food Allergens
The InformAll Database