Get Dirty!

I really enjoy gardening. I've never quite been able to explain why, but sometimes what I really need during the week is a chance to get dirty. Maybe it's a "guy thing" I tell my wife, but digging my hands deep in the soil actually leaves me feeling refreshed in a weird Eual Gibbons kind-of-way. The whole process of digging and planting and seeing things grow is quite a rush. And in more ways than I ever imagined as it turns out. Go figure that a group of researchers at the University of Bristol (www.bris.ac.uk) recently discovered that soil contains "friendly bacteria" called Mycobacterium vaccae (as opposed to "unfriendly bacteria" which I guess will kill you) that activates the neurons in the brain that help produce the brain chemical serotonin. Serotonin you may remember, is that "feel good" chemical that kicks in when we do stuff that we really enjoy. The University of Bristol study is significant because the lack of serotonin in the brain is thought to cause depression in people.

The bigger question -- according to article in Sciencedaily.com -- is whether the serotonin is produced because a person really enjoys playing in the dirt or because of the dirt itself.

Researchers at the University of Bristol explained that Interest in the project arose after human cancer patients being treated with the bacteria Mycobacterium vaccae unexpectedly reported increases in their quality of life.

Apparently Mycobacterium vaccae is present in a variety of things in addition to dirt. A follow up article published in Discover.com points out that "...the results of [this study] so far suggest that by simply inhaling Mycobacterium vaccae a person can a nice emotional jolt..." You can therefore get a dose of M.V. Just by taking a walk in the wild or (as I found out) by digging around in the garden - both of which could help elicit a jolly state of mind.

Dr Chris Lowry, who headed the researcher team from Bristol University was quoted in Sciecnedaily.com saying, "...These studies help us understand how the body communicates with the brain and why a healthy immune system is important for maintaining mental health..." Lowry also mentioned that "...You can also ingest mycobacteria either through water sources or through eating plants - like lettuce or carrots.

Come to think of it, when's the last time you ever saw a depressed rabbit?

But who knows -- maybe what we really need to be doing on a regular basis is playing in the dirt.

An article in Livescience.com recounts that for years the bacteria M. vaccae was being touted as a new treatment for cancer. But that is no longer the case. According to Dr. Lowry, "...Mycobacterium vaccae didn't prolong life, but patients treated with the bacteria did report increases in things like vitality and cognitive function and decreases in pain..." Scientists still don't know how M. vaccae improves mood. But this current research may act as springboard for further study on the subject.

According to Eurekalert.org, the research by Lowry and his team of 12 scientists at Bristol and University College London (UCL) takes this "hygiene hypothesis" a step further by linking exposure to the microbes found in dirt with good mental, as well as physical, health.

In the meantime, you can imagine the look of relief on my wife's face when I tell her I feel like "getting dirty," only to walk right past her, grab a garden hoe and head out into the backyard.