Spilling the beans on bean allergy!
Do beans agree with you? If not, read on. Beans are just one type of edible legume. Other well known legumes include alfalfa, clover, peas, lentils, lupins, mesquite, carob, soybeans, peanut, tamarind and the woody climbing vine wisteria.
While there are over 40,000 types of beans in the gene banks, a small number of bean varieties are used for human consumption. The common bean belongs to the genus/species Phaseolus vulgaris which includes pinto bean, kidney bean, black bean and green bean. Other common beans are the fava (broad) bean (Vicia faba), lima bean (Phaseolus lunatus), and chickpea or garbanzo bean (Ciser arietinum). Beans are an important source of protein and proteins are responsible for triggering allergies! Interestingly, as common as beans are in the human diet, allergic reactions are uncommon. Even though peanuts are legumes, in a U.S. study performed years ago, only 5% of children with a peanut allergy had allergic reactions to other beans tested.
In India and the Mediterranean, lentils and chickpeas have been reported to be the most common legume triggering allergic reactions in young children. In one survey, more than 1/3 of food-allergic individuals who responded reported allergy to chickpea. Anaphylaxis to chickpea is rare with only 1 case report published in the journal Allergy in 1997. The 8-year-old girl with asthma developed hives and wheezing 1 hour after ingesting chickpeas. Previously, she had asthma symptoms after inhaling the flour or the vapors when being cooked. Her evaluation revealed positive skin and blood tests to chickpea and on ingestion challenge in a medical setting with a small amount of chickpea, she had a decrease in lung function, decrease in blood pressure and wheezing on examination. Legume allergy, mainly to lentils and chickpeas, is the 5th most common cause of food allergy in Spanish children. In the U.S., severe bean allergy or anaphylaxis is rare or rarely reported. In 1998, I published a case report on bean anaphylaxis in an adult patient. Click here to read this brief report http://www.jacionline.org/article/S0091-6749(98)70365-3/fulltext#article
Adverse reactions to beans:
- Allergic: hives and skin reactions are the most common followed by rhinitis and asthma especially in children. Bean anaphylaxis in children has not been published in the medical literature. There is much cross reactivity between chickpea, lentil and pea but less similarities between these legumes and beans.
- Non-Allergic: Flatulence or “gas” is the result of the bacterial fermentation of resistant starches or oligosaccharides when the usual enzymes in the gut cannot digest these carbohydrates. This is very common and although not dangerous can be embarrassing especially in a public setting.
Treatment for Bean Allergy:
As with other food allergies, identifying and avoiding the specific bean and those beans that are cross reactive is the primary approach. Being ready in case of an accidental exposure with self-injectable epinephrine is of paramount importance in those individuals at risk for anaphylaxis. Cooked beans can be more allergenic than raw beans and even bean protein inhaled from cooking fumes may trigger an allergic reaction such as asthma.
At Family Allergy & Asthma Care of Montana, we investigate a wide variety of food-induced allergic reactions. If you suspect you have had allergic reactions to beans (non-flatulent) or any other food, contact us, we can help!