Playing through the greenery and litter of a mini-forest’s undergrowth for just one month may be enough to change a child’s immune system, according to a small new experiment.
When daycare workers in Finland rolled out a lawn, planted forest undergrowth such as dwarf heather and blueberries, and allowed children to care for crops in planter boxes, the diversity of microbes in the guts and on the skin of young kids appeared healthier in a very short space of time.
Compared to other city kids who play in standard urban daycares with yards of pavement, tile and gravel, 3-, 4-, and 5-year-olds at these greened-up daycare centres in Finland showed increased T-cells and other important immune markers in their blood within 28 days.
“We also found that the intestinal microbiota of children who received greenery was similar to the intestinal microbiota of children visiting the forest every day,”says environmental scientist Marja Roslund from the University of Helsinki.
Prior research has shown early exposure to green space is somehow linked to a well-functioning immune system, but it’s still not clear whether that relationship is causal or not. The experiment in Finland is the first to explicitly manipulate a child’s urban environment and then test for changes in their micriobiome and, in turn, a child’s immune system.
While the findings don’t hold all the answers, they do support a leading idea – namely that a change in environmental microbes can relatively easily affect a well-established microbiome in children, giving their immune system a helping hand in the process. The notion that an environment rich in living things impacts on our immunity is known as the “biodiversity hypothesis”. Based on that hypothesis, a loss of biodiversity in urban areas could be at least partially responsible for the recent rise in immune-related illnesses.
“The results of this study support the biodiversity hypothesis and the concept that low biodiversity in the modern living environment may lead to an un-educated immune system and consequently increase the prevalence of immune-mediated diseases” the authors write. The results aren’t conclusive and they will need to be verified among larger studies around the world. Still, the benefits of green spaces appear to go beyond our immune systems.
Bonding with nature as a kid is also good for the future of our planet’s ecosystems. Studies show kids who spend time outdoors are more likely to want to become environmentalists as adults, and in a rapidly changing world, that’s more important than ever.
The study was published in the Science Advances.