Let your kids eat mud?

A scientific study supports the hygiene hypothesis.

Mon, Nov 30 2009 at 11:29 AM EST

Photo: gopal103/Flickr

Have you ever heard of the hygiene hypothesis? In a nutshell, it’s a theory that says one of the reasons our children have more allergies and seem to pick up viruses more easily than in the past is because they aren’t exposed to enough dirt and germs. Antibacterial hand soaps, dust-free homes, being stingy with ice cream cones, and not playing in the mud may be doing more harm than good.

Planet Green is reporting that San Diego’s School of Medicine at University of California has research to support the hygiene hypotheses. The research found that “excessive cleanliness at an early age could make children more susceptible to allergies later in life.”

What the research discovered was that staphylococci, bacteria that live on almost everyone’s skin and mucous membranes, aid in reducing skin inflammation around wounds. The study found that these bacteria are important to the natural healing process. The theory is that when a young child isn’t exposed to staphylococci sufficiently early in life, his immune system may not build up what it needs to resist allergies at a later age.

I’ve been hearing about the idea that we’re too clean for our own good for a while now. The first time I became aware of the theory’s name, the hygiene hypothesis, was in Robyn O’Brien’s compelling book The Unhealthy Truth. While she found the hypothesis to have some merit, she sees it as only a small part of the rise in allergies in our children.

O’Brien points to the sharp rise in allergies and asthma that is occurring in children in the inner city where this type of cleanliness is not frequently found. She suggests that other factors such as our children’s overexposure to antibiotics and various toxins are more to blame than cleanliness. She suggests that the name of the theory be changed to the “environmental hypothesis” to remind us that several things in our environment are causing our children to have more compromised immune systems.

While I agree with O’Brien that there are a variety of factors contributing to this, I’m intrigued by the hygiene hypothesis. Maybe I’m drawn to it because mine is not a home where you could ever eat off the floors and because my family shares one soda at the movies as long as no one is obviously sick. It gives me permission to feel just fine about the fact that my bookshelves haven’t been dusted in a couple of weeks.

I also think there’s some common sense in the hygiene hypothesis. Dirt is natural. Antibacterial hand soap is not. And, while we’re on the subject of common sense, before you embrace this hypothesis and let your child lick a friend’s ice cream cone, please do use your own common sense. Right now, there is a flu epidemic raging. It is probably not the right time to be sharing ice cream or movie soda drinking straws. But go ahead and leave your bookshelves dusty. It just may do your kids some good.