For years, scientists have been beating us over the head with tree branches, encouraging us to get out into nature for our mental health. We've even discovered specifics about how time outside helps the brain recover, and we've known under the "hygiene hypothesis" that specific agents in soil--for example, the Mycobacterium vaccae bacteria--can be powerful antidepressants and anti-inflammatories.

But no one had been able to pinpoint exactly how Mycobacterium vaccae protected us from physical and mental health problems. Now, though, scientists from the University of Colorado at Boulder say they've pinpointed it.

Your friend, the fatty acid.

For the study, led by Christopher Lowry, the research team isolated a novel lipid (fatty acid), 10(Z)-hexadeconoic acid, in the bacteria. They then synthesized the fatty acid and used next-generation sequencing techniques to check out how immune cells reacted to it when they were stimulated.

The results showed that, inside the immune cells, 10(Z)-hexadeconoic acid bound to a particular receptor, peroxisome proliferator-activated receptor (PPAR). This essentially puts a kink in the inflammation sequence and shuts it off. And when the researchers pretreated cells with the lipid, those cells were more resistant to inflammation when stimulated too.

Now, the key here is to remember that both physical and mental stress connect to the immune system. The greater your stress, the more jacked and compromised the immune system becomes, the more inflammation has a heyday in the brain and rest of the body, and the crappier your mood and physical wellness are.

Lowry's work, however, suggests there might be therapeutic benefits to the lipid. If that's true, then it might be possible one day to use the lipid as a drug that protects you from these negative consequences of stress. In fact, Lowry envisions using Mycobacterium vaccae as a "stress vaccine" for those in high-stress jobs--first-responders and pilots count, but so do executives, PR agents, and others essential to business.

To vaccinate, or just destroy the disease itself?

There are still plenty of questions to answer, however, such as what kind of dose would be appropriate, or if certain individuals might have predispositions to be more or less receptive to the lipid than others. And Lowry points out there are millions of other bacteria in dirt to explore, any of which could influence whether 10(Z)-hexadeconoic acid can work. So don't expect to be able to head down to your local pharmacy for Stress-Be-Gone just yet.

But maybe the bigger question is, what's better, having a stress protectant, or just not stressing in the first place?

  • While a Mycobacterium vaccae-based drug might keep you healthier in the future, it doesn't change the systems in work that cause so much anxiety and trouble in the first place. We might be served significantly better by attacking and fixing those first. Then, maybe we can turn to a drug for stress that's left, just as simply as we take a daily multivitamin. 

Or, you know, maybe just garden a little.

Excuse me as I reach for a trowel and a pack of marigolds.