Every so often, I'll get a phone call from a distraught parent who has come across her infant or toddler sitting next to a potted plant, face streaked with a mouthful of dirt that he just swallowed.  I usually have to explain that the dirt doesn’t cause any permanent harm. In fact, I tell them, dirt may even reduce the child’s risk of developing allergies or asthma.  Most parents think I'm joking, but there is now scientific data that confirms this.

An Higher Rate of Allergies and Asthma

For years, the rate of allergies and asthma has increased in developed countries. It turns out, as we get better at reducing childhood infections, we’re experiencing more allergies, asthma, diabetes, autoimmune diseases and even obesity.  Scientists have now made correlations between lack of exposure to bacteria in early childhood and the rise of these other conditions.  Being exposed to a chemical that is part of many bacteria helps the immune system down-regulate its tendency to develop allergies. There's even been some discussion among researchers about developing a vaccine that can be used to reduce allergies!

Down on the Farm

Other studies have shown that kids living in farm/rural environments have a lower risk of developing allergies. Farm animals are natural carriers of bacteria, and testing shows that the homes of rural kids have higher bacteria numbers. The more the kids are exposed, the less likely they are to develop allergies.

Children who have been exposed to lactobacillus (a type of bacteria found in milk), attended day care before one year of age and were born via vaginal delivery are also at lower allergy risk.

Pet the Pets

Another factor associated with fewer allergies is having a pet in the house even before the baby is born.  It's unknown if the benefits come from the bacteria that pets carry, or just sheer exposure to their allergens right from the start.

This lends some credence to the stereotype of the kid who lives in a virtually sterile environment—where his mom is constantly cleaning everything he touches and keeps him "quarantined" from other sick kids—who then goes on to develop allergies to virtually everything.  I'm not saying that we should be spoon-feeding our kids dirt or letting them roll in kitty litter, but that "five-second" rule could be expanded to 30 seconds—or even better, let them play in the mud!  It's OK to let kids explore and touch things; that's how they learn about the world around them.

Basically, our society today is dealing with the repercussions of our success in eliminating many childhood infections.  In the past, we focused on the bad things caused by bacteria.  Now we see that in some cases bacteria serve a beneficial purpose.  This is demonstrated by the popularity of probiotics in many of our foods and the benefits that they give us.  Already, many infant formulas are incorporating supplements that help this process along.  We can also see the need for beneficial bacteria when we treat someone with antibiotics and he then develops a yeast infection.

All of this information applies to large groups, so even if you do bring a pet home, go live on a farm or allow your child to eat dirt, he can still develop allergies.  A big component in the risk of developing allergies is genetics.  If one parent has allergies, then the child has a 40 to 60 percent risk of developing allergies. If both parents have allergies, then that risk rises to 80 percent. 

Use Common Sense

It all boils down to knowledge and using common sense.  Let your child explore his world.  If he picks up a three-day old cookie and continues chewing where he last left off, just treat the incident as one of life's little adventures.  If you actually knew what kids put in their mouths, you would probably get sick. (Imagine my terror one day when I discovered my 15-month-old daughter seriously pondering whether to eat the spider she found on a box!)

The bottom line is, don’t be afraid to let kids get a little "dirty." You might be preventing allergies and/or asthma in the future.

William “Dr. Bill” Incatasciato is a pediatrician at Capital Area Pediatrics in the Countryside Shopping Center in Sterling. For more information about Dr. Bill and/or his practice, visit www.CapitalAreaPediatrics.com.

Kids and Dirt