Some recent research has come out that has me (metaphorically) jumping up and down with joy:
Amish children living in northern Indiana have a very low prevalence of allergic sensitization
(Layperson’s summary here – “Is it possible to be too clean? Researchers say ‘yes'”)
The basic breakdown of the research is that exposure to the everyday lifestyle of a farm – dirt, germs, animals, lots of other children, and so forth – seems to be a protective factor against developing allergies in childhood (at least in this sample, which compared Amish children to Swiss farm children to Swiss non-farm children). This is seen as further support for the “hygiene hypothesis” of allergy development, which basically says that early life exposure to microbes (like you get in “dirty” places, such as farms) can be protective.
According to this “hygiene hypothesis,” the human immune system evolved two types of biological defenses. When one defensive system lacks practice fighting bacteria and viruses, perhaps from an overly sanitary lifestyle, the other system becomes too powerful and overreacts — as an allergic reaction — to harmless substances like pollen.
This study is by no means the only one to examine the difference between farm and non-farm children, and the evidence is pretty solid and replicated in a number of populations.
So what does this mean for parents? Well, I think it’s good to recognize that hand washing is a really good thing to do…at certain times. After using the toilet, before eating, when you are sick, if you stick your hand in a giant pile of disease, things like that. But being dirty is okay. It’s normal. It seems to be part of developing a healthy, functioning immune system. Despite the fact that the five second rule is not really true (meaning: germs/bacteria can get on there as soon as you drop some food on the floor), that does not mean that you need to Germ-X the world.
Protecting your child from all possible bacterial dangers is really not very helpful, and is basically impossible. Get a pet, visit a farm (agritourism is booming business and lots of fun), don’t freak out when your kid eats some dirt (it don’t hurt, and could even be helpful).
And if you can’t do all that, and insist on making your children wash and Purell their hands all the time, you can always come see me to treat their contamination OCD (just kidding…kinda).
