Dirty Boot
Credit: David Webb

When my wife, Julie, and I travelled through southern Europe with our 10-month-old son, grandmotherly women would frequently tut-tut disapprovingly as we let him crawl on the ground in public spaces.

As far as they were concerned, the ground is dirty, full of germs and no place for a baby. Ironically, this kind of well-intentioned thinking is contributing to a devastating epidemic spreading through our society that is costing billions, sickening millions and killing too many. In short, our immune systems are failing us. But outdoor enthusiasts are in prime shape to tackle this dilemma head-on.

According to a 2013 study by the Centers for Disease Control and Prevention, food allergies in the U.S. have increased by 50 per cent from 1997 to 2011. This number is only rising, and in 2011 one in 13 children had some type of food allergy. Hospital admissions for severe allergic reactions have increased seven-fold over the last decade alone. Additionally, the rate of autoimmune disorders is also growing at an alarming rate, causing long-term chronic diseases.  

This surge in immune disorders is only happening in more developed countries. The reason is still poorly understood, however, it is becoming increasingly clear that our sterile lifestyles are a major contributing factor. Numerous studies show a strong inverse correlation between the rate of immune disorders and childhood exposure to bacteria. In other words, children living in less sterile environments, such as farms or rural settings, have much lower incidences of allergies than their urban peers, even when consuming similar diets. Households where dishes are hand-washed (as opposed to sterilized in a dishwasher) are also associated with lower incidences of allergies.  

What the studies seem to indicate is that abundant exposure to a broad range of germs at an early age is necessary for our immune systems to develop properly. Exposing children to microbes is as important for their development as providing a balanced nutritious diet or encouraging physical activity.

I remember watching an episode of MythBusters where they investigated the “five second rule.” Every child is familiar with this schoolyard maxim: if you retrieve dropped food within five seconds, it is still good to eat. The MythBusters crew found the rule to be false, and that quickly retrieved goodies were still liberally dosed in creepy crawlies. Ironically, they didn’t bust the biggest myth of all, which is the fundamental misconception behind the five-second rule: that bacteria are bad for you. Really, children should be grinding their candies into the dirt or sticking them in compost heaps and allowing them to sit as long as possible to truly acquire the terroir of the land and to maximize health benefits.

While moms and dads feel compelled to sterilize countertops, children’s toys, floors and anything else we touch, our natural hardwired instincts encourage us to do just the opposite. Take a look at babies. Infants stick anything they can get their hands on into their mouths. During our evolutionary development, these objects would have been rocks, branches, dirt, even excrement scattered around the campsite. Most baby books and online resources state this is simply the baby’s way of exploring the world around them, examining textures and tastes with their lips and tongue; however, this seems a pretty weak explanation for such a strong instinct. A more plausible explanation has recently come up—infants are priming their immune systems by self-administering a broad range of microbes.

The most critical time for immune system development is during infanthood. Researcher Dr. Joel V. Weinstock, the director of gastroenterology and hepatology at Tufts Medical Center in Boston, said in an interview that the immune system at birth, “is like an un-programmed computer. It needs instruction.” This instruction comes from early exposure to a broad range of microorganisms. Unfortunately, infants in our society aren’t getting sufficient immune system guidance from their sterilized toys, and now their health is at stake.

What parents need to understand is that most bacteria don’t make us sick. In particular, bacteria in the soil are usually benign. Sure, many bacteria would start decomposing us like steak in a dumpster on a hot summer’s day if we didn’t have an immune system, but our white blood cells have no problem instantly identifying and destroying these microbes. Pathogens that make us sick mainly come from other people, and the trails they leave on doorknobs and toilets and spray from sneezing. Disease-causing pathogens are rarely found on the ground or in the outdoors, so exposing ourselves to microbes shouldn’t be confused with a dosing of the flu or Norwalk virus.

The great news about this health crisis is that the solution is relatively easy. We just need to be dirtier. Let the kids play in the compost heap and the baby chew on decayed and dirty sticks while out for a hike. When you take the family to the petting zoo, ignore those hand-washing stations and recognize them as monuments to the cause of our allergy-plagued society (I haven’t noticed those healthy farm boys washing their hands every five minutes as they help out on the farm). And when you pull that rotted clog of hair from the plugged drain, give it to the baby as a chew toy (OK, I’m only kidding with that one). Do wash your hands frequently, however, in any situation where communicable diseases are likely to be passed on by others.

It’s summer and there’s no better time to let the kids roll in the dirt. Microbes are most active at this time of year, and we naturally spend more time outdoors where the beneficial microbes live. And for all you campers out there cursing the fact that dishes never seem to get clean with cold water and rationed camp-suds—this year let those greasy plates bring a smile to your face. All in the name of good health. 

This article originally appeared in our Summer 2015 issue.