We’ve taken a look at the various benefits soil provides for our planet in this the International Year of Soils, but one thing we’ve yet to touch on is just how beneficial soil can be to our very own health.

In today’s world it seems like we are waging a chemical war against all things dirt and germs.  Hand sanitizer is sold by the gallon and we are surrounded by campaigns and ads to kill germs and protect ourselves against bacteria and viruses.  But in this hyper-hygienic world are we actually doing ourselves more harm than good?  There is no denying the benefit of proper hygiene and washing one’s hands to keep from getting sick, but like many things, moderation is best and in this instance a little dirt can actually prove highly beneficial.

Dirt is not the enemy.  In fact, the term “dirt” is derogatory so let’s get rid of that word altogether.  Soil—that’s more like it—is, well, it’s amazing!  And it’s far from being our enemy.  Soil is in fact, the very opposite of our enemy—it is our friend.  Soil has not only allowed the Earth to harbor such vast and diverse species of life, it has made life as we humans know it possible.  Soil gives us the structure and foundation on which to live and build shelter, soil provides a medium rich with nutrients for our plants and food to grow, soil provides many wondrous recreation opportunities, soil helps clean and regulate the Earth’s water, and so much more!  Soil is the literal foundation of life on Earth and not only does it do all these things for our planet, it also helps keep us humans healthy in ways we may not even realize.

Soil: Shaping Our Immune System

A growing body of scientific research suggests that soil has the power to train our immune system and may even help prevent myriad inflammatory illnesses later in life like asthma, eczema, or even heart disease, diabetes and Alzheimer’s.

The “hygiene hypothesis” is what scientists refer to as the effect of early exposure to parasites, bacteria, and viruses on human health later in life.  According to this hypothesis, the more someone is exposed to these organisms early in life the less likely they are to develop allergies, asthma, or other autoimmune diseases later in life.

Dr. Thom McDade, associate professor and director of the Laboratory for Human Biology Research at Northwestern University, explains that the immune system is strengthened through exposure to everyday germs because it must learn, adapt and regulate itself.  (WebMD, “Is Dirt Good for Kids?”)

Mary Ruebush, a microbiology and immunology instructor and author of “Why Dirt Is Good,” explains that when a child interacts with his or her environment by putting things in their mouths or playing in dirt, they are allowing their immune systems to practice immune responses.  Conversely, children raised in ultraclean environments are not gaining exposure to organisms that would help them develop appropriate immune regulatory circuits, adds Dr. Joel Weinstock, director of gastroenterology and hepatology at Tufts medical Center.  (The New York Times, “Babies Know: A Little Dirt Is Good for You”)

Early Childhood Exposure is Key

Many researchers say timing is critical to the positive effects soil can play in our lives.  Early childhood exposure to microbes, viruses and parasites is what holds the key for reaping the benefits later in life.  Furthermore, children that grow up on farms, with multiple pets and/or multiple siblings have an even greater advantage against developing allergies or autoimmune diseases.  Farm-raised children seem to enjoy the greatest immune advantage.

According to a New York Times article, “children born to mothers who work with livestock while pregnant, and who lug their newborns along during chores, seem the most invulnerable to allergic disease later.” Scientists believe that farms with greater microbial diversity (including fungi) provide the most benefit for protecting against asthma.  (The New York Times, “A Cure for the Allergy Epidemic?”)

Other Uses of Soil for Human Health

Studies out of the University of Iowa indicate that intestinal worms, which have been nearly eradicated from the developed world, are in fact one of, if not, the biggest factors in regulating the immune system to respond appropriately.  Humans have so adapted to parasitic worms like these that they are largely harmless and there are very few diseases transmitted from worms to humans.  In fact, researchers have been using worms to prevent autoimmune diseases and to treat patients with chronic conditions like multiple sclerosis, ulcerative colitis, and Crohn’s disease. (The New York Times, “Babies Know: A Little Dirt Is Good for You”)

Aside from the direct exposure effects of soil on the human immune system, microbes from the soil can also be found in common remedies to treat illness.  Soil is an important source of organisms from which many antibiotics are made.  Soil is also important for other forms of medication like cyclosporine, a drug derived from a soil fungus that helps prevent organ transplant patients from rejecting their new organs.  (Soil Science Society of America)

In conclusion, if you have little ones who enjoy getting dirty outside—let them at it!  Remember that getting a little dirty can play a major role in keeping you and your family healthy.

Article Sources:

Babies Know: A Little Dirt Is Good for You, Jane E. Brody, The New York Times

Is Dirt Good for Kids?, Lisa Zamosky, WebMD

A Cure for the Allergy Epidemic?, Moises Velasquez-Manoff, The New York Times

Dirty Kids: How Germs Can Be Your Child’s Best Friend, Ben Greenfield, The Huffington Post

Tags: Soil Health, International Year of Soils, IYS, Soil, Healthy Immune System, Human Health, Soils Support Health