I'm not a physician, nor do I play one in the yoga studio. However, sometimes, I wish I had followed through with eight years of post-secondary education and three years of residency, because the body is AWESOME. And as the medical community continues to support aspects of yoga and meditation through scientific studies, exciting discoveries move beyond practitioners' anecdotal experiences and into quantifiable results.
Which brings me to a subject I never tire of researching: the vagus nerve.
The longest nerve in your body, it sends signals between your brain and vital organs, providing status updates and encouraging calm. It's command central for your parasympathetic nervous system, or the "rest and digest" side of the nervous system, which is opposite of the sympathetic nervous system, or the "fight or flight" side. In yoga, you stimulate the vagus nerve for the short term by simply breathing in and out at a regular pace. Sounds oversimplified a bit, doesn't it? Well, I'm trying to keep this short. But the wonderful site Yoffie Life has a much more detailed and helpful explanation. For the YogaIowa Winter '16 issue, I interviewed Dr. Barbara L. Fredrickson regarding her research into the vagus nerve, and how it impacts our emotions, state of physical being, and mental health (read it here on pg. 9). She's completed multiple studies about the vagus nerve and how you can positively affect your vagal tone, which is the relationship between breath and heart rate, and determines how easily your body switches from fight or flight to rest and digest and vice versa. In Fredrickson's research, to improve your vagal tone, you start with breath and build into deliberate meditative practices. The results of a positively-altered vagal tone, according to science, include a more upbeat outlook, less inflammation, more regulated glucose levels, improved emotional connections with others, and a few other noted benefits. (Again, trying to keep this short!)
As a yoga teacher, I have to take caution about absolutely proclaiming that yoga and meditation can and will do this and that for you. It simply wouldn't be prudent to make such concrete statements. But, having said that, these two disciplines have provided benefits for centuries. Medical science as we know it continues to study the body and mind through these practices and find new, important discoveries that legitimize these disciplines. All the more reason to keep practicing!