What Causes Certain Food Allergies And Can It Be Reversed? Here's What A Study Found

One needs to understand how the immune system "memorises" potential dangers, so that it would one day be possible to suppress excessive reactions to allergens.

People who suffer from food allergies know how dangerous it can be to come into contact/accidentally consume food they are allergic to. According to Mayo Clinic, food allergy is an "immune system reaction" that happens after eating a certain food. In fact, consuming even a tiny amount of the allergy-causing food can trigger symptoms like digestive problems, hives or swollen airways. In some people, it can cause severe symptoms or a life-threatening reaction known as 'anaphylaxis'. It is, therefore, understood that people who get sick after eating a specific food, continue to demonstrate a kind of avoidant behaviour towards it.

A study, conducted by Yale School of Medicine and published in the journal 'Nature', found that the immune system plays quite a crucial role. Ruslan Medzhitov, Sterling Professor of Immunobiology at Yale School of Medicine, investigator for the Howard Hughes Medical Institute, and senior author of the study was quoted as saying: "We find immune recognition controls behaviour, specifically defensive behaviours against toxins that are communicated first through antibodies and then to our brains."

Through the study, it has been found that without the immune system's communication, the brain does not warn the body about the dangers in the immediate environment; it makes no effort to avoid those threats either.

During the research, a team in the Medzhitov lab studied some mice sensitised to allergic reactions to ova, a protein found in chicken eggs. Naturally, these mice avoided water laced with ova; control mice, on the other hand, preferred ova-laced water. Researchers found that aversion to ova-laced water in the mice that were sensitised lasted for months. They then examined whether they could alter the mice's behaviour by manipulating their "immune system variables".

Interestingly, it was found that the sensitised mice lost their sense of aversion when their Immunoglobulin E (IgE) antibodies -- produced by the immune system -- were blocked. It is vital to note that IgE antibodies trigger the release of mast cells that -- along with other immune system proteins -- communicate to parts of the brain that control "aversion behaviour".

Now, without IgE, the mice were no longer avoiding the allergen.

These findings, Medzhitov noted, show that the immune system has "evolved" to help animals avoid "dangerous ecological niches". In fact, by understanding how the immune system "memorises" potential dangers, it would one day be possible to suppress excessive reactions to many allergens.