What’s Behind the Spike in Food Allergies?

We are surrounded by evidence of the enormous impact food allergies are making in our society. The peanut butter and jelly sandwich, once a staple of elementary school lunchboxes, has been banned in numerous school districts across the country. Candy bars are required to alert consumers about any other products processed in the factories where they were made. Gluten-free diets are trumpeted by celebrities and have spawned communities of devoted followers (there’s even a “gluten-free” dating site – I’m not making this up).

However, the spectrum of food allergies is still poorly understood by the general public. The phrase “food allergy” conjures one image: a child who, after eating, say, a kiwi, becomes flushed and has trouble breathing until an Epi-pen can be administered. While certainly dangerous, that scenario represents only one aspect of what may be called modern food allergy (or the broader spectrum of food intolerance). Other, milder-appearing food allergies may exist in a larger percentage of the population than previously thought. These mild intolerances can still cause a great deal of discomfort, and when they go unrecognized, may lead to years of expensive and unnecessary testing.

Shortly after my 23rd birthday, I was told by a physician that I’d been having stomach pain because I was allergic to peanuts. How could that be? I thought, remembering stories of peanut allergies that were much more severe than anything I had gone through. The truth, as I later found out, is that allergic and/or immune reactions to food can strike at any age. For unknown reasons, many food sensitivities can present for the first time well into adulthood, while some allergies in children may even be outgrown as the child matures.

The CDC reports that in just 10 years, from 1997 to 2007, food allergies among children rose 18%. This is probably an underestimate and certainly doesn’t encompass all cases of food intolerance. Scientific progress is occurring rapidly, but for now we still only have an incomplete picture of how and why most food allergies are diagnosed. Some, like Dr. Peter Attia of the Nutrition Science Initiative, blame food processing practices; others believe that modern cleanliness is to blame for the increase in allergies – the so-called hygiene hypothesis.

Meanwhile, new manifestations of immune reactions to food are still being discovered. In the early 1990s, researchers identified eosinophilic esophagitis (E.O.E.), which is an allergic-type reaction that’s local to the esophagus. The discovery of E.O.E. has revealed a potentially new danger of food allergies: when left untreated, E.O.E. can lead to extreme difficulty swallowing – even food impaction – via a process called esophageal fibrosis. So, there appears to be some long-term risk in chronic untreated allergy.

Fortunately, virtually everyone affected by food allergies can live healthy and fulfilling lives. The simplest solution is avoiding the allergen altogether. This may not be feasible in people with complex sensitivities to multiple types of food, but even for that small minority there are a wide range of therapies with proven benefits. In the end, even if you’re faced with bad news (like finding out you have to give up your favorite snack: bananas and peanut butter), you can still take charge of your diet and give your quality of life a boost.

Basil Kahwash is an Internal Medicine resident at Indiana University School of Medicine,