Gardeners know it best- time spent in the garden heals their mind and soul, relieves stress, and improves mood. But think about it: you loved playing in the dirt as a child too!
Dogs simply adore it!
So what’s so magical in it? Scientists kept pointing out the possibility of dirt elevating our serotonin levels and thus helping in the case of depression, but the secret was discovered by accident!
Namely, a strain of bacterium in the dirt, Mycobacterium vaccae, has been found to lower anxiety and improve cognitive function.
In 2004, Mary O’Brien, an oncologist at Royal Marsden Hospital in London, published a paper that revealed her findings. She used the harmless soil bacteria on lung cancer patients to relieve their symptoms and strengthen their immune system, but over time, she noticed that it “significantly improved patient quality of life.”
They experienced less pain and nausea and felt happier and in a better mood.
These findings encouraged Christopher Lowry, a neuroscientist at the University of Bristol in England, to do more research.
He injected mice with M. vaccae and found that their cytokine levels which ultimately produce serotonin were higher. He explained that the bacterium “had the exact same effect as antidepressant drugs.”
In a separate observation, Dorothy Matthews and Susan Jenkins, at The Sage Colleges in New York, fed mice little peanut butter sandwiches mixed with dirt. The mice were able to concentrate and think clearer when navigating a maze, their anxiety levels decreased, and the effects lasted for up to 3 weeks!
“Gardeners inhale these bacteria while digging in the soil, but they also encounter M. vaccae in their vegetables or when soil enters a cut in their skin…From our study, we can say that it is definitely good to be outdoors–it’s good to have contact with these organisms.
It is interesting to speculate that creating learning environments in schools that include time in the outdoors where M. vaccae is present may decrease anxiety and improve the ability to learn new tasks.”
So, what are you waiting for? Go outside and roll around in the dirt, take a walk in the wild, or visit the neighborhood park, and you’re likely to encounter some M. vaccae.
If you have a garden, grow some food, as Lowry says you can get the healthy bacterium straight from the food as well:
“You can also ingest mycobacteria either through water sources or through eating plants — lettuce that you pick from the garden or carrots.
A three to four leaf spinach plant has over 800 species of bacteria inside it.”