Edible insects may trigger shellfish allergies undetected by testing kits, caution researchers

01 Aug 2024 --- Researchers at James Cook University (JCU) in Australia warn that food derived from crickets and flies might cause allergic reactions in people who are allergic to shellfish. Furthermore, these allergies may be left undetected in currently available testing methods.

The push for food security has turned the focus on edible insects as a source of healthy and sustainable nutrition globally. Singapore recently approved 16 insect species, including crickets, grasshoppers, mealworms, locusts, moth larvae and one honeybee species, as safe for human consumption.

Professor Andreas Lopata, team leader and head of the Molecular Allergy Research Laboratory and Dr. Shay Karnaneedi from JCU’s Australian Institute of Tropical Health and Medicine note that manufacturers are increasingly using edible insect proteins to meet food and feed needs worldwide.

Despite their nutritious content and the ability to offer a sustainable protein source that’s gentler on the planet, insect-based foods pose a threat of allergic reactions.

“The trouble is that insects are closely related to crustaceans such as prawns, crabs, and lobsters. Crustacean food allergy affects up to 4% of the population, with those people at significant risk of suffering from an allergic reaction after eating insect protein-based foods,” says Lopata.

Analyzing risks
The JCU team has published the study jointly with collaborators from the Australian National Measurement Institute, Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), Edith Cowan University, Agency for Science, Technology and Research and Dr. Thimo Ruethers from JCU’s Tropical Futures Institute in Singapore.

The researchers analyzed seven cricket and two black soldiers fly-incorporated food products for their protein content and potential to cause allergic reactions. They studied two allergen test kits for their ability to alarm consumers correctly.

The team extracted proteins from commercial insect-based foods using five different chemical buffers as part of the study.

The findings reveal that tropomyosin is the most abundant allergen in the insect-based foods tested, similar to shrimp allergens.Key findings
The findings reveal that tropomyosin is the most abundant allergen in the foods, similar to shrimp allergens. In addition to tropomyosin, the researchers identified seven unique allergens, stressing the need for insect species-specific allergen detection in food products.

“We identified proteins (allergens) in insect-based food that can cause allergic reactions in people with shellfish allergy. But we found commercial crustacean allergen test kits did not reliably indicate this,” says Dr. Karnaneedi.

“It means food allergen test kits and food allergen labeling must take into account these unique allergens in edible insects, especially as this will likely be a primary source of food protein for the growing human population.”

“And shellfish allergy sufferers must be aware of potential risks posed by insect-based foods.”

Additionally, urea-based buffers are most efficient in extracting insect allergens.

Professor Michelle Colgrave of CSIRO and Edith Cowan University, adds: “Our study demonstrated that how you chose to extract the insect proteins impacted the identification of allergens within different insect species.”

“More research to standardize detection is needed.”

The Singapore Food Agency (SFA) has developed an insect regulatory framework, establishing guidelines for approving insects as food, including microbiological and labeling standards.

The agency states that the 16 insect species approved currently are not considered to be of higher regulatory concern. Food found to be non-compliant will not be allowed for sale.