If you want your kids to build a greater resiliency against illness, you may want to make sure they spend more time around plants and trees.
A couple years ago in Finland, daycare workers “rolled out a lawn, planted forest undergrowth (such as dwarf heather and blueberries), and allowed children to care for crops in planter boxes” and something fascinating happened: the microbes on the children’s skin and in their digestive tract became healthier in a very short period of time. As Science Alert reported:
The study compared the environmental microbes found in the yards of 10 different urban daycares, looking after a total of 75 kids between the ages of three and five.
Some of these daycares contained standard urban yards with concrete and gravel, while others took kids out for daily nature time, and four had their yards updated with grass and forest undergrowth.
Over the proceeding 28 days, kids in these last four daycares were given time to play in their new backyard five times a week.
The preschoolers at the “greened up” day care centers “showed increased T-cells and other important immune markers in their blood within 28 days” as compared with the urban kids who spent their playtime on pavement, gravel, and tile with little to no greenery.
"This supports the assumption that contact with nature prevents disorders in the immune system, such as autoimmune diseases and allergies," said Aki Sinkkonen, the researcher who led the study, published in Science Advances.
While previous research has pointed to the connection between green space and healthy immunity, this experiment in Finland "was the first to explicitly manipulate a child's urban environment and then test for changes in their microbiome and, in turn, a child's immune system.”
As researchers pointed out, the results will need to be further verified with larger studies in other places around the world. But the benefits of green spaces continue to be made clear in the scientific data.
So if you’re raising a child in an urban area should you feel hopeless?
No. As environmental scientist Marja Roslund from the University of Helsinki (where the research was published) explained, the study also found that “the intestinal microbiota of children who received greenery was similar to the intestinal microbiota of children visiting the forest every day.”
This suggests that a child doesn’t necessarily need to actually be playing in the woods or countryside to get these benefits — “greening” the spaces in which children spend time, no matter where those spaces are, could make a significant impact in their immune systems.
This lends credence to what is known as the "biodiversity hypothesis" — the theory that when our environment is rich in diversity of living organisms, our immunity is impacted for the better. If this is true, an environment that lacks biodiversity, like many urban areas, may be partially responsible for a rise in immune-related illnesses.
The bottom line for families here is that if you want to build stronger immunity, particularly in your children, pay attention to how much time they are getting in green spaces. Get them out into nature more often, and advocate for green spaces in town and city centers, especially where children spend a lot of time.