Food allergies are much more complex than some people imagine – and there’s a lot we don’t fully understand, including exactly why some people develop food allergies and others do not. While food allergies are most often diagnosed in childhood, they can be diagnosed anytime throughout the lifecycle. In addition, food allergies may be more transient than we first believed, as research shows that some people who have become tolerant of an allergy through immunotherapy lose protection when they stop immunotherapy. In addition, significantly more adults than children report convincing food allergies. Let’s take a look at the what the research tells us about food allergy prevalence and some important considerations.
How many people have food allergies?
The prevalence of food allergies in adults is thought to be as high as 10.8%, according to a survey of more than 40,000 subjects. (Gupta, 2019) In the group with convincing allergy, 38% reported having at least one adult-onset food allergy. However, it’s important to know that nearly twice as many reported having a food allergy, but they did not actually have symptoms consistent with IgE mediated food allergies. In addition, this data is limited by the fact that it is self-reported, so oral food challenges were not conducted to confirm allergy. In this group, the most commonly reported food allergies overall in this adult population were (in order or prevalence) shellfish (2.9%), milk (1.9%), peanut (1.8%), tree nut (1.2%), and fin fish (0.9%). And the most common foods that were associated with adult-onset in this group were shellfish, soy, tree nut, and fin fish. Read this article for more about food allergy prevalence.
Do food allergies develop more often in childhood or adulthood?
According to an earlier study of 1,111 medical charts of food allergic adults from an allergy clinic, approximately 15% of these allergic adults had developed their food allergy during adulthood. (Kamdar, 2015) The most common time frame for food allergy development in this population was in their 30’s. The five most common food allergies in this adult population were shellfish (54%), tree nut (43%), fin fish (15%), soy (13%), and peanut (9%). Like the previous study mentioned, these patients did not undergo oral food challenges, which is a significant limitation to the study. In addition, the data was collected from just one clinic.
The answer to the question, “can you all of the sudden become allergic to peanuts?” is certainly yes. Food allergies can develop at any time in an individual’s life. However, it is important to recognize that adult-onset peanut allergy appears to be far less common than other potential allergies, such as shellfish. Indeed, any food can cause a food allergy reaction.
Individuals with questions about a possible food allergy should see a board-certified allergist for proper diagnosis. The signs and symptoms of food allergy may include itching and swelling in the mouth and throat, hives, vomiting, diarrhea, wheezing or difficulty breathing, and could even include a dangerous drop in blood pressure. The more serious types of reactions are often referred to as anaphylaxis. To learn more about food allergies, visit the American Academy of Allergy Asthma & Immunology.
Gupta, R. W. (2019). Prevalence and Severity of Food Allergies Among US Adults. JAMA Netw Open.
Kamdar, T. (2016). Prevalence and characteristics of adult-onset food allergy. J Allergy Clin Immunol Pract, 114-115.e1.