Food allergies can constitute a serious and life-threatening condition, one that has been well studied in children. Less is known about the frequency and severity of food allergies among adults, but, as Mindy Weisberger reports for Live Science, a recent study published in JAMA Network Open is providing new insight into this issue. Researchers found that a significant number of adults in the United States have food allergies—and a significant number mistakenly think they do.
The team surveyed a nationally representative group of more than 40,000 people via the internet and telephone between October 2015 and September 2016. Nineteen percent of respondents claimed to be food allergic, but only 10.8 percent of adult Americans have what the researchers deem a “convincing” food allergy, which is to say that their most severe reaction included at least one symptom on a list developed by an expert panel. For example, reactions might include hives, difficulty breathing or swallowing, vomiting and chest pain.
The study authors aren’t suggesting that people intentionally misrepresented their symptoms; “food allergy” simply refers to a very specific condition that can easily be confused with other ailments. Food allergies are immune system reactions that are triggered because the body perceives certain foods as harmful. Reactions often happen when the immune system produces antibodies known as Immunoglobulin E (IgE) antibodies, but it is possible to have non-IgE mediated reactions.
To the untrained eye, other conditions can look a lot like allergic reactions. Lactose intolerance, for instance, is not the same as a milk allergy, nor is celiac disease, which renders people unable to eat wheat, is also not considered a true allergy. Symptoms after eating certain foods can also indicate “other food related conditions,” says lead study author Ruchi Gupta, a professor of pediatrics at Lurie Children's Hospital Chicago. But these symptoms are not necessarily indicative of a food allergy.
While the number of adults with true food allergies may be less than the reported number, there are still many Americans who suffer from the condition. When projected onto the broader population, the team’s results suggest that some 26 million American adults may be living with a food allergy. “That number is high,” Gupta tells Amina Zafar of CBC News. “It's actually higher than what we even see in kids, which is about eight per cent.”
Most people reported allergies to shellfish, according to the study, followed by milk, peanuts, tree nuts, fin fish, eggs, wheat, soy and sesame. Nearly half of food allergic respondents had developed at least one of their allergies as an adult—an unexpected finding.
“We were surprised to find that adult-onset food allergies were so common,” Gupta says. “More research is needed to understand why this is occurring and how we might prevent it.”
Also surprising was the discovery that less than half respondents with symptoms indicating a true food allergy had their condition confirmed by a doctor. And less than 25 percent reported having a current prescription for epinephrine, a hormone that can combat anaphylaxis, a life-threatening allergic reaction.
The bottom line, according to Gupta, is that suspected allergic reactions should always be checked out by a medical professional. “It is important to see a physician for appropriate testing and diagnosis before completely eliminating foods from the diet,” she says. “If food allergy is confirmed, understanding the management is also critical, including recognizing symptoms of anaphylaxis and how and when to use epinephrine.”