the hygiene hypothesis

An interesting article from ParentMap on the exponential rise of food allergies in children (peanut allergies doubled in five years).

Two leading hypotheses to explain the rise of food allergies, particularly in American children:
- the hygiene hypothesis: Kids used to grow up around more germs from playing in the dirt, and from no Purell. Their bodies now are insufficiently exposed to fairly harmless germs, and they overreact to what should be harmless, namely certain foods.
- the American diet hypothesis: Kids in the US are exposed to too much processed food and genetically modified foods, which their bodies don't recognize as positive things, and try to fight off. Their conclusion: if your grandmother wouldn't have put it on the table, don't.

Makes me feel vindicated in my laid-back (European?) approach to cleanliness; yet additionally concerned that I'm raising them here...