Eating is an intrinsic and essential part of our lives, making food allergies a constant threat at every meal. Researchers from the University of Manchester’s Institute of Inflammation and Repair took a closer look at the dangers of the five most common food allergens, and published their findings in the Journal of Allergy and Clinical Immunology.

"What we wanted was to find a level of allergen which would only produce a reaction in the most sensitive ten percent of people,” said the study’s lead researcher Clare Mills, from the university’s Institute of Inflammation and Repair, in a press release. “This sort of data can then be used to apply a consistent level of warning to food products. What we'd like to see are warnings which tell people with allergies to avoid certain products completely or just apply to those who are most sensitive."

Researchers studied 436 Europeans with at least one of the most common food allergies, which are peanut, hazelnut, celery, fish, or shrimp. They gave them small doses of the foods they were allergic to and closely monitored their reactions. The people who were most sensitive to allergies could only handle between 1.6 and 10.1 milligrams of peanut, hazelnut, and celery. For fish, there was a higher tolerance of 27.3 milligrams, and people with shrimp allergies could handle the greatest dosage at 2.5 grams.

The Elusive Allergy Cure

An allergic reaction occurs when someone’s immune system abnormally overreacts to a foreign, typically harmless substance known as an allergen, according to the Asthma and Allergy Foundation of America. When it’s eaten, inhaled through the lungs, injected, or simply touched, the immune system recognizes it as a danger. In an attempt to protect the body, the immune system produces antibodies that cause histamines to release into the bloodstream. It’s the histamines that trigger allergic reactions such as coughing, sneezing, itchy eyes, runny nose, and scratchy throats. In severe cases it can cause rashes, hives, difficulty breathing, asthma attacks, and even death. There is no cure for allergies, only management through prevention and treatment.

If someone is diagnosed with a food allergy, every bite of every meal must be eaten with vigilance for the rest of their life. An estimated 50 million Americans suffer from all different types of allergies. So why isn’t there a cure yet? Scientists have tried to desensitize patients in the past, with the hope of training their immune systems to accept the misperceived allergens as less threatening. However, gradually introducing allergens to people who have severe reactions can be dangerous. Researchers hope this is the first step toward finding the immune system’s threshold for the 10 percent of people who are most sensitive to them.

Food allergies have been recognized for well over 100 years, and the number of people who are severely allergic to food and certain ingredients has been steadily growing. In recent decades, the number of cases among infants rose the most, between five and seven percent, while it only rose in adults one to two percent. The study was part of an ongoing project called “Integrated Approaches to Food Allergen and Allergy Management,” which is designed to better educate health workers and the public on the dangers of allergy.

"This single study is part of the background to rolling out new warning guidelines across Europe, and alongside other work being carried out in Manchester and elsewhere, we're developing a strong evidence base to give consumers and industry confidence," Mills said.

Source: Mills C. How much is too much: Threshold dose distributions for five food allergens. Journal of Allergy and Clinical Immunology. 2015.