Science & Technology

Different allergens have varied reaction thresholds for people

When food shopping, consumers are advised to read the nutrition label before purchasing an item. There are many reasons for this as some people may be monitoring their sugar intake while others may be analyzing the sodium content. But one thing is for sure: increasing amounts of people are watching out for the allergy alerts in the fine print of the ingredients.

Labels like “contains peanuts” are easy enough: it simply means the product contains peanuts. However, the confusion begins when manufactures put labels such as “may contain peanuts” or “made in a facility that processes peanuts.”  Such labels are ambiguous and can leave the consumer confused and ultimately discouraged from buying the product.

Food allergies are serious, and it is imperative for consumers to understand if their food contains an allergen. An allergy is when the body’s immune system mistakes a benign object, the allergen, as a threat. The body takes action, producing symptoms such as vomiting, diarrhea, hives, increased heart rate and swelling of the mouth and throat. Sometimes these reactions can be life-threatening and require immediate medical attention.

Without a standard in labels and constant ambiguity, consumers are more likely to be discouraged from buying certain products. Researchers at the University of Manchester set up an experiment to find out how much of an allergen it takes for the most sensitive 10 percent of people to reach their threshold.

Although there are many different kinds of food allergens, some are much more prevalent than others. In this experiment, the five most common allergens in Europe were tested: peanuts, hazelnuts, celery, fish and shrimp. Patients were gathered from the EuroPrevall birth cohort, community surveys and outpatient clinic studies to be tested with their respective allergens. EuroPrevall birth cohort is a research project that studies the prevalence and causes of food allergies in the European population. The patients ranged from children to adults.

The experiment was to give people low-dose, double-blind, placebo-controlled, food challenges with the food they are allergic to. Therefore, the subjects tested did not know when they were receiving the allergen or a placebo. The test groups were given in low doses of allergens in order to measure the accuracy and sensitivity of the reaction. The person distributing the allergen and placebo also did not know when the person was receiving the actual allergen. The subjects were divided into three studies, A, B and C.

According to the lab report, Study A patients had either a positive case history or potential allergic reaction to one of the five foods or were sensitized to the five foods, or had a positive skin prick test response without clear clinical tolerance to the sensitized food. Study B patients had a positive case history of reactions for one of the five tested foods and an increase in specific IgE levels in their bloodstream. IgE levels are a measure of immunoglobulin, or antibodies, in the body. The level of antibodies becomes elevated when the immune system suspects a benign foreign protein is harmful.

Study C was selected exclusively based on criterion of a positive case history of an allergic reaction to one of the five foods being tested. However, the researchers ensured that none of the patients tested had a history of anaphylaxis. Anaphylaxis is an acute, life-threatening allergic reaction. Symptoms of anaphylaxis include but are not limited to: hives, sneezing, itching and swelling of the throat, shortness of breath, weak pulse, shock, vomiting, diarrhea, dizziness and/or fainting.

The allergen was delivered to the patient via food consumed. The amount of allergen given increased as each time interval of 20 minutes progressed. After consuming the allergen, patients had to have a reaction within two hours after the last dose. The starting dose was 3 micrograms and went up to a cumulative dose of 1 to 6 grams of protein depending on the food. If patients had a reaction that occurred for about 45 minutes or was severe, the allergy challenge would stop.

Out of the five foods used in the experiment, four had similar dose distributions; 1.6 to 10.1 milligrams of hazelnuts, peanuts and celery triggered a reaction in the most sensitive patients. Fish values were slightly higher, with 27.3 milligrams producing a reaction while shrimp was the outlier of the five, having a value of 2.5 grams of protein. With these findings, scientists have a much clearer understanding of the threshold for people with allergies.

Although there are many more ingredients and proteins to study and research, this experiment has opened a door that will change the livelihood of people. With more information about allergies available, corporations will be able to appeal to a larger demographic of people by ensuring that their food is safe, or at least contain proper warning labels for consumers with high levels of sensitivity to certain products.

According to a study conducted by the Centers for Disease Control and Prevention in 2013, there has been a 50 percent increase of food allergies in children from 1997 to 2011. Food allergies are on the rise, especially in younger generations. Therefore, this new finding will hopefully lead to more knowledge and precaution for those
with allergies.

January 26, 2018

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Sarina Codelia


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