Tag Archives: epidemiology

A Theory About the Increasing Incidence of Food Allergies

Most people in the US who have children (including yours truly) are concerned about the seemingly inexplicable rise in the morbidity of historically rare childhood illnesses. Autism, diabetes, obesity…Why are our kids suddenly subject to these awful conditions in increasing numbers?

Some of these ailments can be particularly troublesome, because we have to be constantly on the lookout for the triggers. Consider for example food allergies: According to the CDC, the incidence of food allergies in children rose 18% between 1997 and 2006. Popular theories as to why have ranged from them living in “germ free” environments due to overzealous cleaning (the so-called “hygiene hypothesis“), to changes in the typical child’s diet in the last forty years. These certainly have merit, however I’ve got a different idea, which was inspired by the recent article by Kevin Drum highlighting a study which showed the astonishing amount of variance in violent crime rates that can be explain by the rise and fall of the presence of lead in gasoline 23 years prior. The striking thing about this study was how events in the past had such a demonstrably strong influence on those in the future. And it turns out there’s an event in the past that occurred before the current crop of food-sensitive children were even born that might provide a useful explanation as to why food allergies are on the rise: The invention of the EpiPen.

EpiPen Autoinjector

The EpiPen was developed in the sixties and seventies by Shel Kaplan out of military research into devices for treating victims of chemical weapons attacks, and it was patented in 1977. It was made available for use in 1980, about 17 years before the meteoric rise in childhood food allergies. This means that in 1997, people born in 1980 or later were around 17 years old, which puts them roughly four years into puberty. Since we know that allergies are highly heritable, we know that children of people with allergies are much more likely to have allergies themselves. And if EpiPens allowed kids born after 1980 to survive into their child-bearing years, more of them are likely to have had kids, which would mean more kids born with allergies. Ipso facto, a rise in the incidence of food allergies, just about the time you’d expect it.

There’s some historical data to support this idea. Hospital admissions for anaphylaxis are up dramatically, which suggests more people are surviving long enough to be admitted. However, despite a reasonably extensive search, I’ve so far been unable to uncover a reliable source of historical epidemiological data on the mortality of anaphylaxis that would provide a clear indication as to whether the mortality rate did indeed drop significantly after the EpiPen became available. If I do eventually find a source, I’ll post an update here. In the mean time, please leave a comment and let me know what you think.

Tagged , , ,