If you’re like most parents and caregivers, you’ve spent a good deal of time teaching your young child the importance of proper hygiene. From taking nightly baths to scrubbing those little hands before mealtime to rubbing on the hand sanitizer, we all work hard to ensure our kids are staying as clean and germ-free as possible.

But what if our kids are too clean for their good? It may sound counter-intuitive but recent studies suggest that being too clean may cause a child to have a hypersensitive immune system. When a child is consistently clean and not exposed to everyday microbes and bacteria, it doesn’t allow for a natural build-up of the immune system. This can result in hypersensitivity and lead to chronic conditions like allergies, eczema, and asthma.

The good news is that a possible solution to helping your child develop a stronger immune system might include an easy piece of advice that most parents never would imagine giving—and that’s telling your kids to play in the dirt.

In a new book called Dirt Is Good: The Advantage of Germs for Your Child’s Developing Immune System, co-author Dr. Jack Gilbert says that exposing children to the everyday microbes found outside in nature—including dirt—can help a child develop a strong, healthy immune system.

Gilbert and other experts refer to a “hygiene hypothesis” that says that as sanitation techniques became better and more accessible in our everyday lives, our general exposure to certain organisms that trained our immune system decreased.

So basically, as a society, we may be more germ-free, but it might be making us sicker.

In a recent study examining the immune system of kids who grew up on rural farms, it was revealed that those kids were less likely to have allergies and asthma. Findings from the study stated that when a child is exposed to molecules from soil-dwelling bacteria found in rural settings, it helps promote the immune system and allows a body to better identify threats from non-threats.

Allergists are also studying whether protecting our body’s barriers — the skin, along with the lining of our respiratory and gastrointestinal tracts — and exposing kids to more bacteria in certain ways could help prevent allergies.

Gilbert says that washing hands too much can break down the skin's barrier, damaging skin and making it more susceptible to infections and allergic reactions. He also recommends that parents and caregivers don’t over sanitize with hand sanitizers and use environmentally friendly cleaning agents in the home.

“The key thing is to ensure that your home is not sterilized top to bottom,” said Gilbert. “Open windows (if you don't live in an overly polluted area) as often as possible or just make sure your kids get a lot of outdoor exposure. Let them get dirty in the woods."

Of course, not all dirty environments are good for kids, and playing in dirt does not mean that a child should be constantly put in unhygienic conditions. Parents and caregivers should also realize the obvious differences between good dirt (fresh soil) and bad dirt (chemically contaminated, near pet droppings, etc.).

So, the bottom line is that allowing kids to be exposed to natural outdoor settings—and yes, even a little dirt—may do wonders for building a healthy immune system. If they’re completely vaccinated, kids should be encouraged to play and explore and get a little down and dirty while they’re at it.

The ABCs of Outdoor Play

To help educate child care providers and the public about the importance of exposing children to natural outdoor settings, outdoor play and education, ABC Quality, Child Care Licensing, and other community partners have used educational resources developed by the Natural Learning Initiative (NLI), a research and extension program of the College of Design, North Carolina State University. NLI’s mission is to promote the importance of the natural environment in the daily experience of all children and their families. NLI works with multidisciplinary partners like ABC Quality to reinforce the critical role of the natural world to support healthy child development, pro-social values, and motivation of learning across all subject areas. Learn more about the importance of outdoor learning environments here.