Food allergy : A new allergen in the field cricket
Food allergy is something common. A large variety of food can provoke a food allergy. The common foods that are involved include cow’s milk, peanuts, eggs, shellfish, tree nuts, some cereals and fruits. The occurence of which food allergy is the most predominant depend on the country. But what about edible insects? It is often and justly said and specified that people allergic to shellfish shouldn’t eat insects. As they are arthropods, there allergens can be the same. A study has put the light on a new potential allergen in the field cricket(Gryllus Bimaculatus), what does it mean? Is this a new food allergy?
Shellfish : A common food allergy
According to the FAO (Food and Agriculture Organization of the United Nations), crustacean and shellfish are recognized as one of the most common causes of food allergy from eight allergenic foods including egg, milk, peanut and soy.
This food allergy occurs more oftenly for adults than children because it can appear and develop during youth. The effects can be various : from itching, nausea to a rare anaphylactic shock.
Like for all food allergies, the mystery around it is still big and further researches are needed. As usual, the allergens are mainly proteins. The principal proteins responsible for food allergy are :
- the tropomyosin, present in the muscle and involve in the movement
- the arginine kinase, an important enzyme for energy metabolism
- the hemocyanin, involved in the transport of the oxygen.
At last and less commonly, the chitin, which is a polysaccharide, present in the shell of the shellfish and crustacean can also be a allergen.
Okay and what about the big member of the family, the edible insects?
Crustaceans and insects : 2 cousins sharing their allergens
Insects and crustaceans belong to the most abundant and diversified (thanks to bugs!) phylum of the animal kingdom : the arthropods. They are defined by their exoskeleton, their segmented bodies and their appanages. Besides insects and crustacean, the other members of this big family are the chelicerates (spiders,acari and scorpions) and the myriapods (millipedes and centipedes).
According to this phylogenetic relation, the literature and different studies, insects and crustaceans are sharing some common allergens. The tropomyosin, the chitin and the arginine kinase in insects are more or less similar to the ones in crustaceans. A cross-reactivity is possible and an allergic reaction after insect gestion for someone who is allergic to shellfish can occur.
The literature about food allergy in relation to insects is still scarce. The allergies related to insects are more often related to contact allergies.
As a precaution and in accordance to the available studies, the EFSA (European Food Safety Agency) and the ANSES (French Food Agency) discourage people allergic to shellfish and mites to eat insects in their reports.
A study published in october 2015 has identified a novel allergen in a cricket specie. This allergen was found in the cricket field (Gryllus Bimaculatus) and is specific to insects.
A new allergen for a new food allergy?
This new and specific allergen found in the cricket is also a protein. This protein belong to the family of the “hexamerins”. What’s an hexamerin? Is it specific to this cricket?
Hexamerins are often referred as “storage proteins” and have been found in all studied insects. Their mainly use is to store and release energy during the periods when insects feed less such as during pupation, before molting and at adult stage. It is also believe that they could play a role in pupation signal. Due to their shape and size, it has been hypothesized that this protein derivate from the hemocyanin, present in crustaceans.
So, this new allergen specific to cricket field is only a derivate of an allergen occurring in shellfish. It’s more like an extension of a shellfish allergy than a new now food allergy, I can continue munching my insects with happiness!
This new allergen was discovered in the field cricket. And what about the other species? The field cricket(Gryllus Bimaculatus) is reared and commonly eaten in Thailand. On the other hand, this specie of cricket is less eaten and reared in Europe and in the USA, we are more accustomed with other species. That’s why this cricket is not in the list of the 10 species allowed to be bred for human consumption in Belgium. We are more familiar with the house cricket (Acheta Domestica) and the tropical house cricket (Gryllodes Sigillatus).
That doesn’t mean that this cricket is less safe to eat that the other insects, it’s just that this cricket was the one studied. Different kind of hexamerins have been found in all insects, so it’s more than probable that the same or other hexamerins present in other species could provoke an allergic reaction.
No panic! Relax, let’s eat some crickets!
The identification of a new allergen in edible insect wasn’t a such surprise. At the present moment, it’s only the beginning of “worldwide edible insect story” that’s been written, and there will be a lot of chapters and discoveries in it.
Last week I wrote about unexpected properties of edible insects, this time it’s a new allergy, what will be next? Maybe a cooking experience?
So, unless you have a food allergy, grab some crickets or mealworms, share them and enjoy them.
That was troubling at first, but then as you expertly broke it down, it made sense. (and reinforced what too often gets ignored, re shellfish allergies. Too many ‘playful’ youtubers joke about pranking friends by tricking them into eating insects….)
Was not sure about trying to post again, but maybe 3rd time’s the charm.
You’re totally right, now it’s one of my first question before giving a try! As you mention, this “prank” could lead to something quite not funny at all…
Thanks for your link, it’s really interesting, I real want to dig into it! Do you know personally the team of Entomofarms?
No, sadly, hence my hesitance to add it to the link box… oh, it auto-filled it from my previous post. Removing it now, sorry, did not catch that!
No! It’s an excellent read that should stay here!
Any possibility of having specifically a cricket or insect allergy without having a shellfish allergy? I can eat the new EXO bars without issue, however my wife has gotten severe food poisoning symptoms both times she tried even a bite of the same bar I ate. She has never shown any allergy to shellfish
Even if the allergens of crickets and shrimps are related, some of them are not exactly the same. So, it could be possible, just as you can be allergic to crabs but not lobster nor shrimps. I think that you’re wife should make some allergen tests or is it possible that another allergen in the bar could have react?
The EXO bars seem pretty clean, per the ingredient list. There is nothing in the bar that she has ever had a reaction to in the past nor was there anything she had never eaten before other than the cricket flour.
There is a possibility that there is something unlisted as far as how the cricket flour is made/processed that could have caused the reaction. With how severe the reaction was both times, I don’t think that I will be able to convince her to try a cricket ever again.
I wonder if she had a reaction to the chitin? I have had stomach issues every time I eat crickets and I have begun to think it is the chitin in the shells. I have no shellfish allergies at all but the one thing that is different between, say, shrimp is that we don’t typically eat the shells whereas in crickets we do.
I experienced strong abdominal cramping, diarrhea and headache after 2 exposures, eating half a bar late in the afternoon and the following morning adding 2 Tablespoons of cricket powder to my smoothie. I tend to be a slow metabolizer, but was surprised that the ill feeling didn’t come on until the evening after the smoothie. Do most people react immediately? I have had other allergic reactions to foods (not shellfish), that have been more immediate. This seemed to not cause a reaction until it got farther down the digestive tract. I feel like Lance’s wife, I am concerned about putting myself through it again.
I just had a major allergic reaction after munching crickets today. Im from the Philippines and cricket is one of the exotic delicacies in Pampanga. It is higly recommended by the residents, so I tried eating one in an established restaurant in Angeles, Pampanga. The taste is good. But after an hour, I began to feel itchy, need to vomit and hives all over my body. I am also allergic to shellfish and seafoods. This page is very helpful. I really wish there’s some kind of remedy or treatment for this. 😭
I just tried roasted silkworms in Thailand and sort of retroactively checked if this can trigger allergic reaction (since I am allergic to crustaceans). Twenty minutes later, I am still okay.
PS: They are delicious
Hi! Thanks a lot for your message !
I’m happy that you liked them and even more important that you’re safe 😉