Summary of How Common Plant-Based Proteins May Trigger Allergies:
According to a study at the University Medical Center Utrecht, legumes are gaining popularity as a protein source due to their high protein, vitamin, and fiber content. Still, legume allergies such as soy and peanuts are common and may be life-threatening. Individuals with soy and peanut allergies may also react to meat substitutes from other legumes. However, most individuals will not experience a reaction. The study found that while cross-reactivity between legumes exists, it may not always lead to clinically relevant co-allergies. The researchers cautioned that an appropriate risk assessment for developing new food allergies during the introduction of novel foods into the market is necessary.
*****
Allergies to Legumes: Are Meat-Free Protein Sources Safe?
As more people turn towards plant-based diets, meat-free protein substitutes are becoming increasingly popular. However, new research has shown that individuals with allergies to legumes such as soy and peanuts may also react to meat substitutes made from other legumes. The study, published in Frontiers in Allergy, aims to answer the question: are individuals with legume allergies at risk from consuming meat-free protein sources made from different legumes?
The increase in legume consumption and production, specifically for protein substitutes, raises concerns about allergic reactions. Researchers found that many legume-allergic patients produce antibodies against more than one legume, indicating a high co-sensitization rate. However, clinical data shows that only a tiny portion of these patients exhibit actual symptoms, suggesting that while cross-reactivity exists, it may not always lead to clinically relevant co-allergies.
What Causes Food Allergies?
People develop food allergies when their immune systems mistake food proteins for threats and produce Immunoglobulin E (IgE) antibodies. Co-allergies occur when patients react to one food respond to another, and co-sensitization happens when patients have IgE antibodies against several foods. Co-sensitization may be caused by cross-reactivity, where IgE antibodies bind to proteins from multiple foods because the proteins share similar structures. Sensitized individuals can develop symptoms of an allergy when re-exposed to the same food.
Co-Sensitization Vs. Co-Allergy
Co-sensitization is common among legume-allergic patients, but it doesn’t always lead to a co-allergy. Patients may be co-sensitized to foods but not experience any reaction when they eat them. Co-sensitization can lead to a diagnosed co-allergy with legumes, but this is not always the case. Researchers found that patients with specific legume allergies react to other legumes up to a certain point.
The Study
Researchers split legume-allergic patients from the Allergology Clinic at the University Medical Center Utrecht into six groups according to allergies: peanuts, soybeans, green peas, lupines, lentils, and beans. Each different group was tested for IgE antibodies against the other legumes. All patients had allergies validated by an oral food challenge or a positive IgE test combined with a history of reactions.
Researchers found that co-sensitization existed between legumes but did not always lead to a co-allergy. Patients allergic to green peas, lupines, or lentils were likely to be sensitized to other legumes, while patients with diagnosed allergies to peanuts or soybeans were not. Pean allergy patients were also often co-allergic to soybeans and vice versa. Dr. Kitty Verhoeckx, one of the study’s authors, noted that many patients produced antibodies against more than one legume. Still, clinical data showed that only a tiny portion of these patients exhibited symptoms.
Conclusion
“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,” said Dr. Thuy-My Le, senior author of the study. “However, this reaction does not always lead to a clinically relevant food allergy. While co-sensitization may exist between legumes, it does not always lead to a co-allergy. Most individuals will not react to consuming meat-free protein sources made from different legumes. However, it is essential for those with known legume allergies to seek medical advice and to be cautious when trying new legume-based products. Introducing novel foods into the market should be accompanied by an appropriate assessment of the risk of developing (new) food allergies.”
