The ninth and final food allergen in our Big 9 Food Allergen series is the leading adult food allergen—shellfish, specifically crustaceans. Not to be confused with an allergy to fish, an allergy to shellfish is a completely independent condition and impacts up to 3% of the United States adult population, and almost 2.5% of the global adult population. With over 100,000 different types of shellfish, it’s no surprise that living with a shellfish allergy can be a hard shell to crack! From oysters to shrimp to lobsters, shellfish have been a relevant and deeply popular component of our food system for millennia.
The first shellfish date back almost 500 million years ago, during the Early Cambrian Period, making them one of the ocean’s oldest creatures! Literally defined as boneless aquatic invertebrates, shellfish are known for their hard exoskeleton: their shell. Though the list of species is nearly endless, shellfish can broadly be categorized into two large groups: (1) crustaceans and (2) mollusks. Crustaceans, like shrimp, lobsters, and crabs, are characterized by their hard shells and legs. Mollusks, like clams, oysters, and mussels, on the other hand, are defined by their hard exterior and soft interior.
Humans have been eating shellfish for approximately 164,000 years according to fossils found in South Africa. Scientists have postulated that shellfish were even critical to human development, with anthropologists stating that shellfish collection by early hominids was one of “the earliest examples of modern behavior!” From prehistoric times to now, shellfish have played different roles in global culinary culture. They were harvested and enjoyed worldwide over the last three millennia ago by indigenous Americans, Ancient Mediterranean Civilizations, and Ancient China and Ancient Japan. In the modern world, shellfish make up a ~66 billion USD global industry! Needless to say, shellfish have penetrated all facets of the global food market and may hide in our diets in ways we don’t even realize!
Unlike an allergy to cow’s milk, eggs, or soy which can be outgrown, a shellfish allergy is usually lifelong, making it all the more important to stay vigilant and learn about the ways in which shellfish can be hidden in everyday foods. Additionally, it’s estimated that approximately 60% of people with an allergy to shellfish don’t experience their first reaction until adulthood! Not all shellfish allergies are the same: of the two families of shellfish, an allergy to crustaceans is much more common than to mollusks. Within crustaceans, shrimp are the most common culprit of allergy. The FDA only recognizes crustaceans as part of the big 9 allergensinstead of all shellfish and hence, only mandates the indication of crustaceans on ingredient labels, not mollusks. However, given that crustaceans and mollusks may be processed at the same facilities and prepared side-by-side, there is a strong chance of cross-contamination, making it hard to discern between potential allergic triggers.
Common sources of shellfish are seafood stews like bouillabaisse, a seafood stew from coastal France, or the popular seafood boils from Louisiana. Some less obvious sources of shellfish are fish stocks and sauces which can sometimes have krill, and processed fish products like imitation crab. Shrimp paste and oyster sauce, in particular, are used in various dishes across Southeast and East Asian cooking and are the ones to be most careful as they are hidden in the food and not explicitly stated sometimes. Outside of food products, some oral supplements could also include shellfish. For example, glucosamine, a joint supplement for bone development, is often made using the exoskeletons of crustaceans and could potentially be an allergen source. This reveals something deeply precarious about our food network: so many products on grocery store shelves may have hidden ingredients that could potentially cause allergies, making it imperative to be careful and aware of the products we buy.
As with the other eight allergens, food transparency is the best way to feel empowered within the global food system. At PuroPlate, our goal is to show people that living with a food allergy does not have to be a burden. With specialized marketplaces, premium technology, and ingredient databases, PuroPlate aims to make navigating the food system easy, and even fun!
References:
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