Toxic fish

Tins of toxic fish have been withdrawn from sale in the UK. Tins of Mas-River fried dace with black beans came from an unapproved source in Malaysia, according to the Food Standards Agency (FSA), the BBC reports.

The fish contain abnormally high levels of histamine (more commonly known for its role in allergic reactions and wasp stings. The histamine can cause scombroid, or scombrotoxic, food poisoning. Its effects resemble those of an allergic reaction and it occurs when spoiled, decayed, fish are ingested. Scombroid syndrome can result from inappropriate handling of fish during storage or processing.

Unlike many types of food poisoning, this form is not produced by a microorganism or virus. Histidine exists naturally in many types of fish, including mackerel, tuna, mahi-mahi, bonito, sardines, anchovies, and related species, and at temperatures above 16 Celsius on air contact is converted to histamine by the enzyme histidine decarboxylase produced by Morganella morganii. Histamine is not destroyed by cooking, so even properly cooked fish can be affected. Histamine levels are not reduced by freezing, smoking, curing and/or canning.