In the case of fish allergies, complete waiver of fish is not always necessary
Many people suffer from a food allergy, with fish allergy being one of the less well-known forms, although it is quite realistically common. Affected people respond to fish consumption with symptoms such as indigestion, nettle fever or even an anaphylactic shock. Until now, lifelong fish waiver was the only option. However, an international team of researchers has now been able to prove "that fish allergy sufferers do not necessarily have to do without this healthy diet," according to the latest report from the Luxembourg Institute of Health (LIH).
In the case of a fish allergy, fish consumption has so far basically been taboo for those affected. The advice to people with an allergy to fish was to avoid this food completely, reports the LIH. However, the international research team led by Dr. Annette Kühn and Professor Markus Ollert from LIH and Dr. Martin Sørensen from the University Hospital North Norway in Tromsø is now showing that it is not absolutely necessary to do without fish in the event of a fish allergy. The scientists published their study results in the journal "Journal of Allergy and Clinical Immunology".
Fish allergies are relatively widespread
The fish waiver that has been implemented so far in the case of a fish allergy must be viewed critically, since fish is usually an extremely healthy food. It is an important supplier of easily digestible proteins and supplies the body with iodine and essential omega-3 fatty acids. However, fish is also a food “that very often triggers a lifelong food allergy with clear symptoms,” reports the LIH. An estimated 0.1 percent of the population is affected worldwide. In Luxembourg, where a lot of fish is consumed and processed due to the high proportion of the population from the Mediterranean, these allergies are more common.
Different proteins trigger the allergic reaction
All fish allergy sufferers have in common that their immune system reacts to certain proteins of the fish with the formation of antibodies. This allergic reaction is often caused by parvalbumin, "a protein that is found especially in the muscle cells of the white meat of various fish species," the researchers explain. But be Dr. Kühn and her colleagues recently succeeded in proving "that the fish proteins enolase and aldolase can also trigger an overreaction," the LIH said. Accordingly, not all fish allergy sufferers are allergic to the same fish species.
Fish allergy sufferers do not react to all types of fish
The study author Dr. Annette Kühn reports: "In our study, we were able to show that about every third person affected does not have an allergic reaction to individual fish species." In addition, it was possible to "identify certain markers that can be used to distinguish people with an allergy to one or more fish species . ”This has great benefits for those affected, since some allergy sufferers tolerate certain fish species and therefore - despite their hypersensitivity - would not have to do without this valuable source of protein.
Looking for biomarkers
So far, it has only been possible to find out whether there is an allergy to many different types of fish, a so-called cross-allergy, using very complex tests in which fish are given orally. Bold. Together with colleagues from Norway and Sweden, the researchers therefore tried to identify certain markers in the blood of patients that can be used to determine the respective form of fish allergy. They administered cod, salmon and mackerel to 35 patients with a proven fish allergy and then determined the antibodies in their blood.
Different antibodies detectable
In the course of their investigations, the researchers found that "allergy sufferers form different antibodies, depending on whether they are only hypersensitive to parvalbumin or to the fish proteins enolase and aldolase," reports the LIH. This is the first time that the researchers have succeeded in proving that people with a cross allergy to several fish species can be distinguished using specific markers (antibodies). "This is important to avoid unnecessary dietary restrictions, especially in allergic children who very often have multiple food allergies," emphasizes Martin Dr. Sørensen.
New possibilities in allergy diagnostics
The results of allergy research close to the clinic open up "completely new possibilities for molecular and thus personalized allergy diagnostics", explains Dr. Thanks to the specific antibodies, it will hopefully be possible in the future to "identify certain forms of fish allergy at an early stage and to give those affected meaningful nutritional tips for risk avoidance." to preserve and thus prevent the development of allergies. (fp)