Why Do Farm Kids Seem to Have Fewer Allergies Than Urban Kids?

What Women Really Think
June 11 2012 2:50 PM

Does Geography Matter in Childhood Allergies? 


Photo Illustration by Scott Olson/Getty Images

For over a decade now, pediatricians, parents—and perhaps especially the school lunch lady—have become increasingly aware of childhood allergies, particularly of the food-related variety. Stories of reactions (sometimes life-threatening) to nuts, shellfish, and gluten seem increasingly common, and a kid arriving at a birthday party with a list of food restrictions is not unexpected. So what’s going on here? Is there really an epidemic of childhood allergies, and if so, what’s to blame?

A pair of studies out in the past few weeks offer, if not a complete answer, at least some hints. Scientists studying the demographics of childhood allergies have found a correlation between population density and prevalence: Kids in cities are more likely to be sufferers, while rural kids (like the Amish) seem to have fewer problems. Researchers hypothesize that this might be due to the “farm effect” or “hygiene hypothesis,” the notion that children raised around animals and in natural environments more generally are more likely to develop hardier immune systems early-on, while Clorox-wiped urbanites sanitize their children to a fault.


On the one hand, this idea is compelling, if only because it jibes with the current anxiety that our children’s exposure to the outdoors is declining dangerously. But, as Meredith Broussard wrote in Slate back in 2009, these kinds of studies are often dubious in terms of design, not to mention funding sources. The main problem is that researchers rely on responses to surveys, which, of course, are subject to the biases of self-reporting and memory. And parents who take the time to respond to such a survey are likely already invested in the subject emotionally, further clouding their answers.  

So these results are, at best, inconclusive; however, they also may well be onto something—only further research into the actual mechanisms of the farm effect (is the magic in the fresh milk or the hay or both?) will explain the correlation. Until then, getting the kids outside a little more often is probably not a bad idea, but I’d hold off on buying a cow. 

J. Bryan Lowder is a Slate assistant editor. He writes and edits for Outward, Slate’s LGBTQ section, and for the culture section.



The World’s Politest Protesters

The Occupy Central demonstrators are courteous. That’s actually what makes them so dangerous.

The Religious Right Is Not Happy With Republicans  

The XX Factor
Oct. 1 2014 4:58 PM The Religious Right Is Not Happy With Republicans  

The Feds Have Declared War on Encryption—and the New Privacy Measures From Apple and Google

The One Fact About Ebola That Should Calm You

It spreads slowly.

These “Dark” Lego Masterpieces Are Delightful and Evocative


Operation Backbone

How White Boy Rick, a legendary Detroit cocaine dealer, helped the FBI uncover brazen police corruption.


Talking White

Black people’s disdain for “proper English” and academic achievement is a myth.

Activists Are Trying to Save an Iranian Woman Sentenced to Death for Killing Her Alleged Rapist

Piper Kerman on Why She Dressed Like a Hitchcock Heroine for Her Prison Sentencing

  News & Politics
Oct. 1 2014 7:26 PM Talking White Black people’s disdain for “proper English” and academic achievement is a myth.
Oct. 1 2014 2:16 PM Wall Street Tackles Chat Services, Shies Away From Diversity Issues 
Oct. 1 2014 6:02 PM Facebook Relaxes Its “Real Name” Policy; Drag Queens Celebrate
  Double X
The XX Factor
Oct. 1 2014 5:11 PM Celebrity Feminist Identification Has Reached Peak Meaninglessness
  Slate Plus
Behind the Scenes
Oct. 1 2014 3:24 PM Revelry (and Business) at Mohonk Photos and highlights from Slate’s annual retreat.
Brow Beat
Oct. 1 2014 9:39 PM Tom Cruise Dies Over and Over Again in This Edge of Tomorrow Supercut
Future Tense
Oct. 1 2014 6:59 PM EU’s Next Digital Commissioner Thinks Keeping Nude Celeb Photos in the Cloud Is “Stupid”
  Health & Science
Oct. 1 2014 4:03 PM Does the Earth Really Have a “Hum”? Yes, but probably not the one you’re thinking.
Sports Nut
Oct. 1 2014 5:19 PM Bunt-a-Palooza! How bad was the Kansas City Royals’ bunt-all-the-time strategy in the American League wild-card game?