Shellfish Allergies? Bugs May Be Off the Menu Too

By Olivia Barney

As populations increase around the world, many are looking toward more sustainable food sources. Ideally, these are protein-rich options that take less space to farm or have a smaller impact on the environment. Though the practice of eating insects is currently common across most places outside of Western Europe and parts of North America, experts anticipate the trend to spread in the coming years.

You read that right. Insects might keep our stomachs full.

Farming crickets, for example, requires up to 90% less land than cattle, leaving only a third of the water footprint created by cattle farms. Crickets are also extremely nutritious, with a higher protein content than pork, chicken, or goat.

But the insect revolution isn’t an option for everyone.

Roughly 2% of the world is allergic to shellfish — that’s 166 million people globally, and 6.8 million people in the United States alone — making it twice as common as peanut allergies. Those who are allergic to shellfish (crustaceans, mollusks, and cephalopods) know how to keep themselves safe, but if you’re allergic to shellfish, you’re likely allergic to insects too.

Why People With Shellfish Allergies Shouldn’t Eat Insects

Though it might seem surprising, shellfish and insects are related. They both belong to a group of invertebrates called Arthropoda (individuals within this group are called arthropods). It’s the same group that includes spiders and mites.

Most people, when they hear that shellfish allergies correlate with insect allergies, assume that it has to do with this taxonomic relationship, but that’s not the case — at least, it’s not the full story.

Simplified classification of the insect species discussed in "Allergens from Edible Insects: Cross-reactivity and Effects of Processing" Marchi et al.

All arthropods have a shared evolutionary history, which means that everything from spiders and dragonflies to crabs and lobster, have developed with similar molecular structures. The proteins that make up one species are very similar to the proteins that make up another. Those molecular similarities set the stage for cross-allergens, but it’s the proteins themselves that cause the reactions. 

Allergies are an individual’s immune system responding to specific proteins, and some proteins are more likely to cause reactions than others.

Pan-allergens are proteins known to cause reactions in allergic individuals, and they’re found in a wide variety of things: plants, animals, and synthetic materials (like latex). Tropomyosin (TM) is a sub-group of pan-allergens which is specifically based in animals. Shellfish are full of TM, as are insects and arachnids. This is the main pan-allergen that links shellfish and insect allergies, but it isn’t the only one. Arginine Kinase (AK), alpha-amylase, actin, and hemocyanin have also been found across both groups.

In short, the shared evolutionary history between bugs and shellfish increases the likelihood of finding similar protein families. Some of these protein families are known pan-allergens, making it more likely to have a mite allergy if you’re already allergic to shrimp (as just one example).

No Allergies? Try These Tasty Insect Treats

Though research into these cross-allergens is still ongoing, preliminary data suggests that if you’re allergic to shellfish, you should avoid eating insects too.

For those who aren’t allergic to either group and want to get a taste for the bugs that may appear in our future meals, visit BugFest at NHMU to snack at our famous Bug Bar. From termite mac and cheese bites to grasshopper tacos, water bug cucumber salad to ant-infused chocolate espresso tartlets, we think you’ll be pleasantly surprised at the tasty treats we have to offer.

BugFest takes place on August 8-9, 2026, at the Natural History Museum of Utah. Join us for expert lectures, hands-on workshops, bug-themed art and jewelry, and so much more! Tickets are on sale now. As BugFest is one of our biggest events of the year, we highly recommend purchasing tickets in advance and arriving early to ensure ample time for parking.

References

De Marchi, L., Wangorsch, A., & Zoccatelli, G. (2021). Allergens from Edible Insects: Cross-reactivity and Effects of Processing. Current allergy and asthma reports, 21(5), 35. https://doi.org/10.1007/s11882-021-01012-z

Lopata, A. L., Kleine-Tebbe, J., & Kamath, S. D. (2016). Allergens and molecular diagnostics of shellfish allergy: Part 22 of the Series Molecular Allergology. Allergo journal international, 25(7), 210–218. https://doi.org/10.1007/s40629-016-0124-2

Magara, H. J. O., Niassy, S., Ayieko, M. A., Mukundamago, M., Egonyu, J. P., Tanga, C. M., Kimathi, E. K., Ongere, J. O., Fiaboe, K. K. M., Hugel, S., Orinda, M. A., Roos, N., & Ekesi, S. (2021). Edible Crickets (Orthoptera) Around the World: Distribution, Nutritional Value, and Other Benefits-A Review. Frontiers in nutrition, 7, 537915. https://doi.org/10.3389/fnut.2020.537915