Dear Jeff,

Neither I nor my siblings or siblings-in-law have food allergies, but each one of my nieces and nephews has a food allergy, save my baby niece and who knows what will happen there. We all eat relatively healthy foods (with the exception of a little fast food here and there) and my siblings all keep spotless homes and the kids are healthy otherwise.... so what's going on?

With all the health scares we hear about, it's tempting to start taking them lightly. But food allergies are a real and possibly growing problem.

Scientists aren't exactly sure there is in fact an increase in childhood food allergies, let alone what the causes are.

But one theory, the so called "hygiene hypothesis," suggests something counter-intuitive: that we are in fact keeping our homes too spotless.  If a child's immune system doesn't get a good workout early on, it may respond too enthusiastically later on.   For more information about the hygiene hypothesis, see my group's new report:  Asthma: Causes, Diagnosis, and Treatment.

I am not suggesting being a slob around the kids -- but there's not need to overdo it, either.  Unfortunately, a healthy diet won't prevent -- or help one avoid -- food allergies. In fact, allergies to healthy peanuts are among the most common --and dangerous food allergies out there. And meanwhile, I've yet to meet the kid allergic to french fries!