A study led by Mount Sinai School of Medicine on 15,000 participants revealed that one in 50 people had a seafood - shrimp, crab and lobster, squid, scallop, clams, mussels, and snails - allergy and one in 250 reported a fish - cod, salmon and tuna - allergy.
The onset of seafood allergies is likely to begin in adulthood and frequent, severe reactions are reported by sufferers. Among adults, women reported more allergies than men, and among children, boys were affected more often than girls. The highest rate, 3.7 per cent, of seafood allergies was reported by African-Americans.
"Further studies are needed to determine the reason for women and minorities having a higher rate of seafood allergy, whether it is cultural eating differences, associations with environment exposures or other explanations," said Scott Sicherer, assistant professor of pediatric allergy and immunology in the Jaffe Food Allergy Institute at Mount Sinai School of Medicine, and co-author on the study.
The researchers put the rise in allergies down to growing seafood consumption of both finfish and shellfish, which has increased by some 25 per cent since 1970.
"More specifically, the seafood consumption rate has risen from a per capita consumption of 12.5 pounds in 1970 to 15.6 pounds in 2002," said the scientists.
According to The Food Allergy & Anaphylaxis Network (FAAN), in the US alone about 11 million people - roughly one in 25 - are now believed to be affected by one or more food allergies, a disease triggered by the ingestion of certain foods that may cause life-threatening reactions, or anaphylaxis.
In Europe, tough new rules on food allergen labelling will come into force later this year to tackle problems associated with food allergies. Directive 2003/89/EC, amending Directive 2000/13, means that manufacturers will have to list all sub-ingredients of compound ingredients, and so allergens cannot be 'hidden', a move that heralds an end to the 20-year-old '25 per cent' rule.
A panel at the European Food Safety Authority earlier this year claimed that there was ample evidence to justify the mandatory inclusion on food labels of the most common food allergen ingredients and their derivatives: cereals containing gluten, fish, crustaceans, egg, peanut, soy, milk and dairy products including lactose, nuts, celery, mustard, sesame seed, and sulphites.
FAAN has launched a Seafood Allergy Registry open to anyone with an allergy to any type of fish or shellfish.