A new study that looked at common, meat-free alternatives created with legumes found they can trigger peanut and soybean allergies in some people. Photo by 821292/Wikimedia Commons
March 16 (UPI) -- A new study that looked at common, meat-free alternatives created with legumes found they can trigger peanut and soybean allergies in some people. That, researchers said, should signal a warning for those who want to eat meatless proteins.
In research was published Thursday in Frontiers in Allergy, Mark Smits and a team of scientists at University Medical Center Utrecht in the Netherlands found that while legumes are an attractive sustainable protein source, those with allergies must be concerned about possible reactions.
"Many people keen to reduce their meat consumption are turning to substitutes made of legumes packed with protein, vitamins, and fiber," the study said. "But allergies to legumes like soy or peanuts are both common and dangerous."
Thuy-My Le, the senior author of the study, said the issue has become more common with more people looking for meat alternatives to eat healthier.
"An increase in the consumption of legumes may increase the number of allergies to these foods," Le said in a statement.
"Furthermore, these new legumes may elicit allergic complaints in already legume-allergic patients. Therefore, we investigated how often sensitization and allergy to different legumes occurs in these patients."
Food allergies occur when a person's immune system confuses food proteins with a threat and produces Immunoglobulin E, or IgE, antibodies.
Upon re-exposure to the same food, some can develop symptoms of an allergy. Co-sensitization can happen with cross-reactivity, where IgE antibodies bind to proteins from multiple foods because the proteins share similar structures.
The University Medical Center Utrecht split validated study subjects into six allergy groups: peanuts, soybeans, green peas, lupines, lentils, and beans. Each group was tested for IgE antibodies against the other legumes.
"We showed that a large number of patients produced antibodies against more than one legume," Kitty Verhoeckx, second author of the study, said in a statement. "However, clinical data showed that only a small part of these patients had actual symptoms."
The study said 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.
The research said that the high co-sensitization rate was associated with clinical symptoms in only a 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.
"Legumes are an attractive sustainable protein source, but allergic reactions in the already legume-allergic population cannot be excluded as antibodies in the blood of legume-allergic patients frequently react to different legumes," Le said.
"However, this reaction does not always lead to a clinically relevant food allergy. Introduction of novel foods into the market should be accompanied by an appropriate assessment of the risk of developing (new) food allergies."