This is simplified information about legume allergies – there are more resources available at the bottom of the page for further reading for those who are interested in knowing more.
Legumes are the edible fruits or seeds of plants in the family Fabaceae
. We can further define them as the seeds of podded fruits. Legumes are a common food staple globally as for the most part they can be dried and stored with ease. In their dried form legumes are known as pulses.
As with other groups of foods we cannot lump all legumes together in terms of allergy – different legumes contain different combinations of allergenic proteins, so they are not easily defined or categorised.
Which beans aren't legumes?
have the right shape to be considered as legumes, but they are not in the Fabaceae
family of plants, so are not considered to be true legumes. Coffee is in the Rubiaceae
family of plants.
are in the Orchidaceae
family of plants, closely linked to orchid plants, so are not true legumes either despite their shape.
are in the Malvaceae
family of plants which includes okra, cottons and durian fruits. Cocoa beans are the seeds of this tree which are used to make chocolate, cocao and cocoa butter. Cocoa beans are not true legumes.
are in the Euphorbiaceae
family of plants. They are actually seeds rather than beans.
Which legumes are related?
Working out which legumes are related can be confusing as many of them have the same species and genus name but are known by multiple names.
For example, green beans are the pod of the plant Phaseolus vulgaris
, but kidney beans are the mature bean from within the pod of the same plant. Other names for kidney beans are haricot beans, pinto bean and white beans. The full list below has been grouped by species.
In the diagram below you can see other beans are closely related as they have the same genus name (The first capitalised name), but the species name is slightly different. For example, red beans, black beans and mung beans all look very different but are in same genus – Vigna
Table showing which legumes contain which allergenic proteins
Table is sorted alphabetically by species to show which legumes are the same but have multiple names.
Information in this table is from multiple resources – please visit the Food Allergy Index
for information on each food.
You can download a Legumes Factsheet from the Allergy Resources Ko-fi Shop
for just $0.50 (£0.40 or €0.45).
Seed Storage Proteins
Seed Storage Proteins are split into three main types, 2S seed storage albumins
, 7S seed storage globulins
(also called vicilin) and 11S seed storage globulins
(also called legumin). Albumins are water soluble proteins found more often in nuts and seeds, globulins are found more often in legumes.
Seed storage proteins are the most common allergen associated with nut, seed and legume allergies and have a greater potential to cause a severe allergic reaction which may include anaphylaxis if accidentally ingested.
Seed storage proteins are heat stable, meaning that heating (and in many cases, freezing or processing) does not damage the shape of the protein, so it does not lose its ability to cause allergic reactions.
You can download a Seed Storage Protein Factsheet from the Allergy Resources Ko-fi Shop
for just $0.50 (£0.40 or €0.45). This has up to date information on which foods contain linked allergens and what to avoid if you think you have an allergy to seed storage proteins.
Other foods containing seed storage proteins are tree nuts, peanuts, sesame, kiwi and coconut.
Lipid Transfer Proteins
Lipid Transfer Proteins
(also called LTPs) are panallergens found in many groups of foods and can cause serious allergic reactions. It is often the allergen found to be linking what initially looks like lots of random food allergies together. Lipid transfer proteins are stable when cooked or processed.
Foods containing LTPs are almonds, apple, banana, cherry, celery, kiwi and peach.
Bet v 1 Proteins
Bet v 1
allergens are linked to Pollen Food Allergy Syndrome
, which was previously called Oral Allergy Syndrome. These terms are still used interchangeably.
In this syndrome a person first becomes sensitised (allergic) to a tree or plant pollen. The most common in Pollen Food Allergy Syndrome is birch tree pollen. The allergenic protein in birch tree pollen is called Bet v 1. A person can then find themselves allergic to other proteins in foods which are similar to Bet v 1 proteins, often called Bet v 1-like or Bet v 1 homologues. Bet v 1 proteins are found in a wide range of foods including fruits, vegetables, nuts, seeds and grains.
The symptoms of this syndrome are called oral allergy symptoms as they can cause sneezing, itchy mouth and lips as well as a scratchy throat and tongue. All in all, these fruits can cause a general irritation of the mouth, nose and throat. It is very rarely serious enough for the throat to close as it does in anaphylaxis.
The Bet v 1 allergens are often referred to as ‘heat labile’, meaning that the proteins are damaged by heat and lose their ability to cause an allergic reaction. There are more proteins in the skin of the fruit than in the flesh and seeds. If you can eat the fruit once heated or peeled with no or reduced allergic reactions then you should be able to determine if this is Pollen Food Allergy Syndrome or a true IgE allergy (an IgE allergy will have immediate symptoms which may include anaphylaxis, swelling and/or hives).
Other foods containing Bet v 1 allergens are peanut, celery walnut, cherry, apple, peach and pear.
are panallergens which have the potential to cause allergic reactions over lots of groups of foods and cause people to suffer from multiple food allergies.
Allergic reactions to profilins are linked to oral allergy symptoms, more specifically they are linked to Celery-Mugwort-Spice Syndrome
, which is a subtype of Pollen Food Allergy Syndrome.
Profilins are less likely to be cause anaphylactic allergic reactions and the proteins themselves are easily denatured with heat and processing.
Other foods containing profilins include celery, peanut, walnut, lupin, almonds, mustard and other various fruits, grains and vegetables.
Tamarind contains a chitinase
protein, this is one of the allergenic proteins responsible for Latex Allergy
, it has cross reactivity with similarly shaped proteins in the skin of the fruit which can cause an allergic reaction; this is called Latex Food Syndrome
Chitinase allergy is usually linked to the skin of fruits such as banana, mango, jackfruit and kiwi.
proteins are a lesser-known allergenic protein found in plants. The proteins are involved in preventing the build up of oil molecules and may have a role in lipid store degredation during plant germination.
Oleosin proteins have been shown to maintain their shape after thermal processing, for example, studies have shown that roasted peanuts (in their shell) had more allergenic oleosin proteins than peanuts which were not heated.
Other food containing oleosin proteins include peanut, hazelnut, sesame, buckwheat and quinoa.
If you are interested in which foods contain which allergenic proteins you can visit the Food Allergy Tool Page
Why do some foods have no named allergens?
Some of the legumes in the table above have no allergens listed. The World Health Organization (WHO) has a database where they record all well studied allergens in certain foods. If there are none recorded then there have not been enough studies into this food. If you are interested in what is needed by the WHO before they add an allergen to their nomenclature database you can look at that HERE
Most of the entries in the table above are supported by the WHO allergen database and some are from individual studies. The ones that are assumed due to similar genus’ have been discounted.
If you are interested in cross reactivity of foods the most up to date information is on the Cross Reactivity Tool.
More about gums
Guar gum, gum Arabic and locust bean gum are all legumes and are listed above. These are common additives in foods which gives them thickening and stabilising properties. They are highly processed, so don’t commonly cause food allergies, but it is not impossible to be allergic to them.
Most studies show legume sourced gums are more likely to be associated with occupational contact allergic dermatitis.
What are lectins?
Lectins are carbohydrate binding proteins found in lots of plants including many legumes. Lectins can cause gastointestinal symptoms of food intolerance and mistaken for a true IgE food allergy. The amount of lectin in foods can be reduced by soaking and cooking. You can read more about food intolerances on the Food Intolerance
page, visit individual foods on the Food Allergy Index
to see which foods may be causing a problem or visit the dedicated Lectin Page
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