Why some people develop allergies while others don’t?

Allergies can be very hard to live with, because they are caused by the most common foods, plants or dust, which makes it difficult to adapt to the environment. Some allergic reactions produce simple rashes or discomfort, but they can go as far as being lethal.

High amounts of histamine release, triggered by the immune reaction some bodies get from non-pathogenic substances can become dangerous because the two most important functions of histamine are: causing an inflammatory response and the constriction of smooth muscles, which becomes a threat as these muscles surround the airways, thus shortness of breath appears or asthma attacks as it is more commonly known.

More importantly, until now scientist couldn’t explain why some people are allergic to various substances, while others aren’t. What triggers this exaggerated immune response to harmless solutions? Dr. Nicholas Furnham from the London School of Hygiene & Tropical Medicine, might have found the answer. As part of our body’s evolution, our immune system has evolved to easily recognize parasitic infections and start fighting against it. Apparently, in the absence of a parasitic infection, some immune systems that are hyper-responsive, might mistake proteins from non-pathogenic substances for proteins found in a parasite’s body. By studying this theory, researchers have identified a protein in a parasitic worm which resembles a protein believed to only be encoded into the genomes of plants.

This spectacular finding means that allergic people have a hyper-responsive immune system to parasites, just like how in autoimmune diseases the immune system believes that its own cells are a threat and starts fighting against them, in allergies the immune system mistakes some proteins with parasites and starts giving a proper response, which leads to unwanted symptoms.

Even more, now scientists can start to predict which proteins from food or the environment might get mistaken with parasites and lead to better prevention and treatments.