Fennel is in the Apiaceae
family of plants which also includes carrot, coriander, dill, parsnip and parsley.
There are no recorded allergens for fennel by the World Health Organization (WHO), because there have not been enough study into allergic effects from this food. If you are interested in what is needed by the WHO before they add an allergen to their allergen database you can check that out HERE
Fennel has been shown to contain Lipid Transfer Protein
(LTP), these are panallergens with the potential to cause allergic reactions over large groups of foods.
Fennel is also though to contain plant profilin proteins
, which are also panallergens which are food in lots of different groups of food.
Fennel also contains furanocoumarins
. These chemicals can get on the skin and in combination with ultraviolet light (sunlight) can cause a sunburn like rash. Furanocoumarins are found in higher concentrations in fresh herbs and are natural irritants which can cause allergic contact dermatitis. This is more common in occupations where you are frequently coming into contact with the food, like chefs, cooks, growers and pickers.
It is sometimes found in toothpastes and mouthwashes, which is important to note if you think you are allergic to fennel.
Fennel is a high FODMAP food.
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.
Fennel is a food moderate in salicylates
. Salicylates have the potential to cause worsening of asthma, swelling, itching and hives as well as food intolerance symptoms in people who are sensitive to salicylates.
You can read more about Food Intolerances
on the dedicated Food Intolerance Page.
Allergy to fennel is linked to Celery-Mugwort-Spice Syndrome
, which is a subtype of Pollen Food Allergy Syndrome
. This syndrome affects individuals who have become sensitised to pollen and then have oral allergy type symptoms to foods with similarly shaped proteins. The most common form of Pollen Food Allergy Syndrome is the one caused by birch tree pollen. In Celery Mugwort Spice Syndrome the sensitising pollen is mugwort.
Fennel may also be a food to avoid if you have LTP Syndrome
, if you cannot eat fennel even after it has been processed or cooked you may have LTP Syndrome.
The foods most commonly linked to Celery-Mugwort-Spice Syndrome are peach, melon, celery, carrots, camomile, fennel and other spices from the Apiaceae
family which include coriander, caraway seed, celery, chervil, cumin, dill, aniseed and parsley.
Profilins are also found as food allergens in kiwi, celery, peanut, chilli, watermelon, orange, hazelnut, melon, carrot, strawberry, soya, walnut, lychee, lupin, apple, cherry, almond, peach, pear, mustard, tomato and aubergine.
Other plants containing profilin inhalant allergens are ragweed, wormwood, birch, sunflower, olive, plantain, poplar and oak.
Common foods involved in LTP allergy include kiwi, strawberries, sunflower seeds, walnut, apple, mulberry, banana, pea, apricot, cherry, plum, almond, peach pomegranate, raspberry, tomato, grape, celery, peanut, asparagus, cabbage, broccoli, chestnut, lemon, tangerine, orange, hazelnut, lettuce, lentils, lupin, green bean, pear, mustard, wheat and maize.
Note that these food lists are not exhaustive, the most up to date information is on the Cross Reactivity Tool.
Science Direct - Fennel
Allergen Encyclopedia - Fennel
Healthline - FODMAP Foods
ATP Science - Salicylate Foods
Articles and Journals
Food allergens in oral care products, 2023
Current Insights on the Impact of Proteomics in Respiratory Allergies, 2022
Severe allergic reaction to allspice, a hidden food allergen, 2022
Structural characterization and in vitro lipid binding studies of non-specific lipid transfer protein 1 (nsLTP1) from fennel (Foeniculum vulgare) seeds, 2020
Fennel Allergy Is a Lipid-Transfer Protein (LTP) - Related Food Hypersensitivity Associated with Peach Allergy, 2013
Mugwort-fennel-allergy-syndrome associated with sensitization to an allergen homologous to Api g 5, 2013
Relevance of pollen‐specific IgE levels to the development of Apiaceae hypersensitivity in patients with birch pollen allergy, 2007
Characterization of allergens in Apiaceae spices: anise, fennel, coriander and cumin, 2006
Fennel, cucumber, and melon allergy successfully treated with pollen-specific injection immunotherapy, 2000
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