Kidney beans aren’t used widely in British cuisine, in fact the only meal I’ve ever used them in is chilli so a recent bout of full-on head, eye, nose and allergic reactions recently took a bit of detective work. We narrowed it down to the chilli and it wasn’t until cooking it without kidney beans because we didn’t have any in the cupboard that the penny dropped.
So why would I suddenly have a pretty awful allergic reaction, instantly, while eating chilli with kidney beans one week, just out of the blue? A little bit of research helped to shed some light onto the rather confusing legume family.
So what’s a kidney bean?
The kidney bean, also known as red bean, is a common bean (Phaseolus vulgaris) and also part of the legume family.
It’s called a kidney bean because it looks a bit like a kidney and is also a similar colour.
Kidney red beans can be confused with other beans that are red, such as azuki beans and they can also be called “red peas”.
They are most commonly used in chilli-con-carne and are widely used in cooking in India and can also be used to make refried beans which is a Mexican dish. In Spain caparrones are small fried kidney beans.
Kidney beans are more toxic than most other bean varieties if not pre-soaked and subsequently heated to the boiling point for at least 10 minutes.
What are legumes?
The legume family consist of beans, peas, lentils and peanuts but there are loads of different varieties:
- Arabic/Gum Arabic (derived from acacia)
- Bean sprouts
- Beans – Baked – Black – Black turtle – Broad – Brown – Butter – Fagioli – Fava – Garbanzos (another name for chickpeas) – Great Northern – Guar – Haricot – Jack – Kidney – Lima – Masur – Mongo – Mung – Navy – Pink – Pinto – Red – Snap – Tonka – Wax – White
- Locust bean gum
- Coffee pod
- Clover Fenugreek – in curry, chutney, and/or dhal – in cinnamon – in halva – may be in pickles
Garbanzos – gram flour – hummus – in Burmese Tofu – in falafel – in farinata – in Indian food “chana” – in poppadoms
- Gram flour (derived from garbanzos)
- Green beans
- Guar gum
- Lentils – in dal
- Mesquite – in barbeque liquid smoke – in charcoal and as gluten free flour
- Peas – Blackeyed Peas – Chickpeas/Garbanzos – Cowpeas – Field pea – Green – Purple hull – Snow Peas – Split Peas – Couscous!
- Rooibos – in tea
- Senna (another name for cassia) – in laxatives – may be in curry (but is probably just the cassia tree bark, rather than the cassia legume)
- Soya beans
- String beans
- Tamarind – in Worcester sauce – in HP sauce – used as an herbal tea – in sambhar – in chutneys – in many Mexican candies, one is called pulparindo
I was most surprised to see Rooibos and vanilla in this list (Noooooo – not the rooibosh tea?) and also tamarind, which I also use in Thai cooking and mesquite which I use in baking cakes and cookies. I’m pretty sure none of these cause me a problem but if you are getting unexplained issues it’s really interesting to examine a food family like this.
What is kidney bean allergy?
A kidney bean allergy is rare, but if you react to other legumes then they may cause you a problem e.g. peanuts and soya beans, which are two of the top fourteen most common allergens.
A kidney bean allergy is the result of an overactive immune reaction to the proteins found in the bean. Shortly after eating the kidney bean, your body sees the proteins in the food as an invader and begins to defend itself with antibodies and histamine. Antibodies are released to fight off the kidney bean proteins, and histamine attempts to protect the body from infection. Too much histamine causes inflammation in soft tissue in various places in the body. This is the main cause of most kidney bean allergy symptoms.
Symptoms from a kidney bean allergy can vary from mild to moderate. In rare cases, you may develop a severe allergic reaction that can cause anaphylactic shock. Common symptoms include nasal congestion, asthma, digestive complications and skin rashes, according to Mayo Clinic. You may become short of breath, have difficulty breathing, begin wheezing, coughing and sneezing. Digestive symptoms include diarrhoea, vomiting, nausea and stomach pain. Your skin may react by forming hives or eczema anywhere on the body.
One study in India entitled ‘Kidney bean: a major sensitizer among legumes in asthma and rhinitis patients from India’ can be found in PlosOne, 2011. Read the abstract here – Kidney bean: a major sensitizer among legumes in asthma and rhinitis patients from India.
Luckily for me this didn’t cause anaphylaxis, just hives, itching on my skin and a huge amount of mucous like with a really bad cold or hay fever but these allergic reactions can change over time. One exposure could give you cold like symptoms and the next time it could cause anaphylaxis. Understanding your body and what it’s reacting to and why is really important but often mystifying if you can’t pinpoint which ingredient is causing you the problem.
I was suspecting chilli, pepper, herbs and spices, cross contamination of some kind and not even thinking about the humble kidney bean. But I’m very glad to get to the bottom of that one. And rather glad it’s kidney beans, which I don’t even like that much, so no great loss!
Anyone else out there with an allergy to all legumes? or can you eat some legumes? Have you also had new legume or other allergies accumulate over time?
References – further reading
To read more on the difference between nuts, seeds and legumes read ‘Nuts and seeds’.
Kidney beans are also very high in lectins, find out more about this on the Foods Matter website.