Be a little dirty: It's good for you!

Scientists are discovering why getting dirty in your garden can be good for you in more ways than just producing & consuming healthy fruits and vegetables. New research suggests it may be good for your head as well as your body. (h/t Ethicurean digest)

Some researchers have proposed that the sharp rise in asthma and allergy cases over the past century stems, unexpectedly, from living too clean. The idea is that routine exposure to harmless microorganisms in the environment—soil bacteria, for instance—trains our immune systems to ignore benign molecules like pollen or the dandruff on a neighbor’s dog. Taking this “hygiene hypothesis” in an even more surprising direction, recent studies indicate that treatment with a specific soil bacterium, Mycobacterium vaccae, may be able to alleviate depression. For example, lung cancer patients who were injected with killed M. vaccae reported better quality of life and less nausea and pain. Now a team of neuroscientists and immunologists may have figured out why this works. The bacteria, when injected into mice, activate a set of serotonin-releasing neurons in the brain—the same nerves targeted by Prozac.

And who wouldn't rather take Peas than Prozac?