Food Allergy Numbers: Why the Mystery?
As someone who has a personal and professional connection to food allergies, I probably talk about the subject more than most. During these conversations, I’m often asked questions about food allergy science, management, and awareness. As a result, I’ve grown pretty proficient at fielding most food allergy questions thrown my way (at least I’d like to think so ☺). However, there’s one question that I dread answering since my response will almost surely disappoint. Here it is: How many people have food allergies?
The answer? It’s complicated. Not what you were hoping to hear, right? Read on, I promise to share some great food for thought on why this question has no easy answer!
First, let’s review some commonly referenced food allergy statistics:
- As many as 15 million Americans have food allergies
- Approximately 9 million adults have food allergies
- Approximately 5.9 million children have food allergies (1 in 13, or 2 in every classroom)
- Between 1997-2011, food allergy prevalence among children increased by 50%
- Food-allergic children are 2-4 times more likely to have related conditions such as asthma (4x), atopic dermatitis (2.4x), and respiratory allergies (3.6x)
Now let’s dig a little deeper. A 2011 study published in Pediatrics found that the prevalence of allergy among food-allergic children was highest for peanut (25.2%), followed by milk (21.1%), and shellfish (17.2%). The results of a recent national survey of 53,000 families showed that peanut allergies in children have increased 21% since 2010, and that 45% of adults develop at least one allergy after age 17—which is surprising, considering food allergies are commonly thought to present themselves in childhood.
These stats all sound pretty solid, no? Well, they're not exactly. Here’s why.
Numerous variables come into play when discussing prevalence statistics for food allergies, making firm figures difficult to come by. To name a few:
- Old data. A lot of the figures referenced above are 5-10 years old. This past week, the New York Times published an article citing a wheat allergy statistic that is nearly a decade old (and this appears to be the most current figure!).
- Self-reported data. Most food allergy research is collected through self-reported diagnosis (individuals are polled and asked to identify their food allergies). Some have been diagnosed by allergists, but others may have had one reaction their whole life and attribute that reaction to a specific food that they’ve avoided since (as one example). Many folks also mistake a food allergy with an intolerance, which can further muddy the data.
- False positives. The best diagnostic technologies out there aren’t always 100% accurate, as we discuss in two earlier posts: Food Allergies Today: An Expert Q&A and More Tools, More Problems? Food Allergies Since 1960. False positives are frequent and regularly occur during allergy testing. For example, my daughter consistently tests moderately allergic to almonds and sesame with the ImmunoCAP test (a test that measures the body’s level of allergen-specific IgE antibodies), but she frequently eats both foods with no symptoms.
In short, it’s hard to pin down just how many Americans (and individuals worldwide) have a food allergy, making this question an especially tough one to answer! As we advance our understanding of food allergies, one can only hope that this knowledge helps us to better diagnose, manage, treat, and prevent.
In the meantime, continued research, emerging therapies like OIT, and technology will lead the charge and give hope to this growing population.
- Meg and the Allergy Amulet Team