Common meat-free proteins may trigger soybean and peanut allergies

Many people keen to reduce their meat consumption are turning to substitutes made of legumes packed with protein, vitamins, and fiber. But allergies to legumes like soy or peanuts are both common and dangerous.

Both protein consumption and the world’s population are increasing which leads to an urgent demand for sustainable protein sources, reports a senior author of the study published in Frontiers in Allergy. An increase in the consumption of legumes may increase the number of allergies to these foods. Furthermore, these new legumes may elicit allergic complaints in already legume-allergic patients. Therefore, they aimed to investigate how often sensitization and allergy to different legumes occurs in these patients.

Researchers recruited legume-allergic patients from the Allergology Clinic at the University Medical Center Utrecht and split them into six groups according to allergies: peanuts, soybeans, green peas, lupines, lentils, and beans. All patients had allergies validated by an oral food challenge or a positive IgE test combined with a history of reactions. Each different group was tested for IgE antibodies against the other legumes.

All six patient groups showed co-sensitization to additional legumes, and almost a quarter of patients were sensitized to all legumes. Nearly all the patients in the bean allergy group were sensitized to other legumes. Patients allergic to green peas, lupines, or lentils were also likely to be sensitized to other legumes, while patients with diagnosed allergies to peanuts or soybeans were not.

The high co-sensitization rate was associated with clinical symptoms in only a relatively small number of patients. In peanut and soybean-allergic patients, co-allergies for green pea, lupine, lentil and bean were uncommon, but patients who had allergies to this second group of legumes were likely to be co-allergic to peanuts or soybeans.

Patients with peanut allergies were also often co-allergic to soybeans, and vice versa. Co-sensitization for peanuts was associated with clinically relevant co-allergy in almost all the other legume groups. However, the team cautioned that it will be necessary to expand the study to a larger group and confirm co-allergies with oral food challenges to determine how clinically relevant this co-sensitization is in practice.

Reference:

Common meat-free proteins may trigger soybean and peanut allergies in some people; Frontiers in Allergy, DOI: 10.3389/falgy.2023.1115022