AsianScientist (Jan. 9, 2020) – Being able to consume any food you desire is a privilege that most people take for granted. However, some individuals have to be very careful about what they ingest lest they suffer hives, breathing difficulties or nausea and vomiting.
These symptoms are typical of allergic reactions to certain compounds in food—the body’s immune system overreacts to an otherwise harmless substance, causing significant discomfort. Food allergies are more common in children than adults, with some studies reporting that nearly five percent of children under five years old react adversely to food such as peanuts, shellfish and wheat or soy products.
“For a child with a food allergy, the burden is not just physical, but also psychological,” said Dr. Soh Jian Yi, a consultant with the Division of Pediatric Allergy, Immunology & Rheumatology at the National University Hospital of Singapore. “Besides the risk of allergic reaction, the child, and his or her parents, have to constantly worry about the ingredients inside food items, which can be very tiresome.”
Although the instinctive response to food allergies is often to completely avoid the allergen, Soh’s research has shown that the immune system can be ‘trained’ to tolerate an allergen to a greater extent. Working on peanut allergies in children, he has developed an oral immunotherapy approach that gradually raises the threshold amount of peanuts that his pediatric patients can take.
“We now know that with food allergies, there is a threshold of reactivity. Suppose that a person has a tolerance level of ten milligrams of peanuts. What that means is, if that person takes less than ten milligrams of peanut at any time, nothing will happen because that amount is below the cut-off tolerance level,” Soh explained.
The challenge, therefore, is to identify the cut-off tolerance level for each individual. In a study published in the journal Asia Pacific Allergy, Soh and colleagues recruited nine Singaporean children between 4-18 years of age who had peanut allergies and gradually exposed them to increasing amounts of peanut protein, taken orally, up to a maximum dose of 3,000 milligrams of peanut protein.
The researchers reported that seven of the nine study subjects were able to tolerate at least 3,000 milligrams of peanut protein by six months of maintenance therapy.
“So eventually, we may be able to shift the tolerance threshold up to as high as, for example, ten peanuts. Now, can someone accidentally eat ten peanuts? That’s very unlikely to happen. The moment you cannot accidentally eat the food in a quantity that would be a problem, you no longer need to check or worry about that,” Soh said.
Nonetheless, the results of the study also showed that tolerance does wear off over time, suggesting that children who have completed the oral immunotherapy should continue to consume a minimum amount of peanut regularly to sustain tolerance. Having said that, Soh cautions parents against carrying out their own dose escalation regimes without professional medical guidance.
“Rigorous training and the appropriate scientific equipment is needed to measure out the right doses safely,” he said.
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Copyright: Asian Scientist Magazine.
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