There’s no denying that getting outside and having a good dig in the garden gives you a positive feeling. Even after a stressful day, a five minute wander around the backyard pulling a few weeds and sprinkling the seedlings immediately calms me. But is there a scientific reason for why getting our hands dirty makes us feel happy?
According to a study at two prestigious UK universities, gardening might provide a more effective way to get rid of the blues than Prozac.
The breakthrough discovery conducted on laboratory mice revealed the existence of ‘friendly bacteria’ in the soil, which can naturally increase the levels of serotonin in the brain, resulting in the same effect as prescription antidepressants.
Identified as Mycobacterium Vaccae, the bacteriain soil cause cytokine levels to rise, which results in the production of serotonin. Gardeners inhale the bacteria, have topical contact with it and get it into their bloodstreams when there is a cut or other pathway for infection.
The bacterium was tested both by injection and ingestion on rats and the results were increased cognitive ability, lower stress and better concentration on tasks than a control group.
Aside from having the potential ability to also strengthen the immune system, the study also revealed that this bacteria present in the soil can ‘trick’ brain cells into producing more serotonin. A lack of serotonin has been linked to depression, anxiety, obsessive compulsive disorder and bipolar problems.
The experiment found that the natural effects of the soil bacteria antidepressant was felt for up to three weeks after contact. The one disclaimer for this is the use of Roundup, a 2008 study showing that the active ingredient in the common poison – glyphosate – will undo all the good effects by depleting serotonin and dopamine levels.
Another way science is showing us how time in the garden makes us happy relates to the dopamine rush we receive when harvesting. Researchers are saying that this response evolved over nearly 200,000 years of hunting and gathering, when a successful food forage would result in a dopamine spike in the reward centre of the brain, triggering a state of bliss or mild euphoria. Apparently this dopamine release can be triggered by the mere sight or smell of a ripe fruit or berry in front of us.
I’ve heard from many people that gardening is their ‘happy place’, enhancing their good mood and smoothing out the stresses of the day. Backing it up with science is fascinating, but hardly news. Perhaps just an added excuse (if we ever needed one) to leave the emails and the dishes behind and step out the back door to greet the green.