By Stuart Layt
You might have thought crocodile meat was a bit “fishy” — now research has confirmed that’s more the case than previously thought.
A study led by researchers from James Cook University found crocodile meat contained parvalbumin, a protein similar to that found in many types of fish, and which causes an anaphylactic reaction in people allergic to fish.
Research co-author Professor Andreas Lopata said they were already working with a group of about 100 children from The Children’s Hospital at Westmead, Sydney, and Epworth Hospital, Richmond, on allergy profiles.
“We saw some case studies from overseas about anaphylactic reactions to crocodile meat, and decided to test our child cohort to see if they also had this reaction,” he said.
“Fish allergy appears to be more common in children, but the results we found were still surprising when we tested for crocodile meat.”
Of the 77 children who displayed a fish allergy, 70 per cent registered a reaction to the crocodile meat in skin prick tests and blood tests.
Research co-author Dr Thimo Ruethers said the anaphylactic reaction was a result of the protein found innately in crocodile meat, and was not transferred to the meat because a crocodile had eaten lots of fish.
“We have now coined the term ‘fish-crocodile syndrome’: fish-allergic individuals may be at risk of serious allergic reactions upon consumption of crocodilian meat due to them being highly reactive to crocodile parvalbumin,” he said.
“This generally harmless protein is now the very first reptile allergen registered with the World Health Organisation.”
Crocodile and alligator meat is increasingly being eaten as a relatively cheap source of protein.
In Australia, crocodiles are farmed for meat, and the country accounts for 60 per cent of the global trade in crocodile products, including meat and skins.
A 2017 Ernst & Young report commissioned by the Northern Territory government estimated the crocodile farming industry was worth $106 million to the territory’s economy.
Fish allergies are one of the most common allergies worldwide, with symptoms ranging from mild intestinal discomfort to severe anaphylaxis.
People who suffer from a fish allergy must often avoid all products that may contain fish, and Lopata said their discovery of cross-reactivity with crocodile meat added another factor for those affected to consider.
“When people travel abroad, especially to south-east Asia, crocodile is often served and it is not always clearly labelled in the same way it would be in Australia,” he said.
“More broadly, we hope this will help parents of children with a fish allergy to avoid another potentially high-risk food.”
The research has been published in the journal Pediatric Allergy and Immunology.