Gardeners claim that getting their hands in the dirt makes them happier, and some say that pulling weeds actually helps them feel calm and peaceful. It seems that recent scientific evidence may support their claim as working in the soil may be much more than a simple matter of connecting with Mother Nature.
What is it about dirt that can reduce anxiety and promote feelings of happiness and well-being? Research indicates that the credit goes to Mycobacterium vacaae, a tiny bacterium that lives in the soil. Mycobacterium vacaae is just one strain of the many types of microbes found in soil.
The Research
Like many studies, research on the bacteria has involved both mice and men (and women). In one study, researchers exposed mice to the bacterium, and then placed the mice in a container of water for five minutes. It turned out that mice exposed to the bacteria behaved in ways similar to mice that received antidepressant medications; they were willing to swim much longer than unexposed mice that gave up relatively quickly.
Bacteria-exposed mice were also able to find their way through a complex maze easily with little evidence of stress, while “normal” mice had more difficulties. Surprisingly, mice benefited from exposure to the bacterium for about three weeks before effects began to taper off.
The results of the studies were somewhat similar to a medical trial involving cancer patients. Although the bacterium unfortunately didn’t reduce cancer or prolong life, exposure decreased pain and stress, significantly improving the quality of life.
Scientists are hoping to find out exactly how the bacterium works. Some believe it triggers a chain of events that includes release of serotonin, a brain chemical associated with cognition, mood and memory. Lack of serotonin has been linked to a number of disorders, including anxiety, depression, bipolar disorder and obsessive-compulsive disorder.
Although researchers are hopeful, it’s too soon to predict whether the bacterium may be used to treat depressive disorder, or if it might benefit individuals who are in drug and alcohol treatment or rehab for help with addiction or mental health disorders.
However, digging in the dirt doesn’t cost a penny and you might just feel happier and more serene.
