With the rising instances of food allergies in India, are scientists any closer to finding a cure?

Living with peanut allergy can feel like having a sword hanging over your head 24x7: especially in India, where peanuts are a favourite for sweet and savoury dishes from Maharashtra to Bihar and from Punjab to Tamil Nadu.

Yet for someone allergic to peanuts, even a waft can give them hives and lands them in the emergency room of a hospital.

Food allergies, or an adverse reaction to food items from eggs to shellfish, milk and peanuts, are an abnormal response of the body. Usually, eating or touching a food item you’re allergic to sets off the immune system which then produces histamines (an inflammatory mediator) to fight what it thinks is an attack on your body. The results can vary from sniffles to anaphylactic shock.

Researchers around the world are looking for alternatives to antihistamines and epi-pens for managing allergic reactions, especially in children.

Allergies in India

Traditionally, India has had a low incidence of food allergies. Thanks in part to Indian genes, which protect us from allergic rhinitis (sniffles), asthma and eczema, according to a March 2019 article published in the Journal of Evolution of Medical and Dental Sciences.

But this is slowly changing now, as lifestyles change and people become more prone to conditions like lactose intolerance and allergies to dust mites. A study with 588 people selected at random in Karnataka, in 2016, found that more than 26% of participants had food allergies.

Not so nuts about peanuts

Allergies have everything to do with an individual’s immune response, wrote S.V. Gangal and B.K. Malik in ‘Food allergy - how much of a problem is this really in India’, published in the Journal of Scientific and Industrial Research. They wrote that in certain populations, peanut proteins act as an antigen - something that provokes an immune response.

The immune system forms IgE antibodies (there are five types of antibodies, the IgE type are secreted mainly in response to an allergy). These IgE antibodies bind with mast cells or basophils (immune cells) and “sensitize” them. In this context, sensitization is akin to awakening them. So that the next time this person consumes peanuts, the mast cells or basophils release inflammatory mediators in large numbers - causing a range of symptoms like diarrhoea, asthma, rhinitis, urticaria, eczema, hives.

Treatment options

Currently, there is no cure for food allergies. The mainstay treatment for severe peanut allergy is prompt administration of epinephrine - which relaxes the respiratory airways. There are specific devices available commercially for self-injecting epinephrine, too. After administration of epinephrine, all patients should be transported to a medical facility, where additional treatment can be given, if required.

But antihistamines and epinephrine provide relief from the symptoms rather than the allergy itself. Research is now focusing on the latter. One such method is oral immunotherapy: little by little, medical practitioners administer minuscule amounts of the food allergen to patients in the hope to induce tolerance.

Usually, in an allergic reaction, the body produces IgE antibodies to fight the antigen. In oral immunotherapy, the idea is to use these antibodies — called monoclonal antibodies because they are made by the same immune cells that react to the allergen — to bind the immune cells (basophil or mast cells) so they can’t react adversely any more.

Earlier this year, a report in The Lancet — one of the most well-regarded peer-reviewed science journals in the world — showed that oral immunotherapy to treat peanut allergy in children has its limitations. In a meta-analysis, the researchers found that it increased the risk and frequency of anaphylactic reaction in clinical applications.

It’s early days yet. Every day, we understand more about how the immune system works. And as allergies strike deeper roots across the world, and in India, medical practitioners are stepping on the accelerator to find new ways to address them.

Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health. To know more on this topic, please visit  https://www.myupchar.com/en/disease/food-allergies