The Science Behind Yoga
Recently I came across a post on Facebook titled "The Science Behind Yoga." It took me a while to make the time to sit down and watch it, but I finished watching it this week and I took what the video offered and dug a little deeper.
I was struck by the eloquence (and credentials) of one of the interviewees for the video. His name is Sat Bir Khalsa, PhD. He is the Assistant Professor of Medicine at Harvard Medical School and has published many scientific research papers evaluating the clinical effectiveness and basic psychophysiological mechanisms underlying the practice of yoga and meditation techniques.
This is the sort of scientific research of yoga that I can get behind one hundred percent.
As he spoke, I made a list of the research papers he was referencing as part of his presentation. I've compiled them into this list for easy reference.
- Studies of autonomic functions in practitioners of yoga in India
- Cerebral blood flow differences between long-term meditators and non-meditators
- A Wandering Mind Is An Unhappy Mind
- Mind wandering and attention during focused meditation
- Yogic meditation reverses NF-κB and IRF-related transcriptome dynamics in leukocytes of family dementia caregivers in a randomized controlled trial
- A Systematic Review of Randomised Control Trials on the Effects of Yoga on Stress Measures and Mood
- Yoga on our minds: a systematic review of yoga for neuropsychiatric disorders (download link)
- Mind-body interventions for the treatment of insomnia: A review
My take away from the studies I read from this list (some are not available without purchasing the full reports) is that the meditative aspects of the physical asana practice manifest themselves when you are focusing on your breath during a held pose while you're holding the pose instead of wondering how much longer it will be before the instructor calls the next pose so you can get out of the one you're currently in. These moments of meditation, feeling the air move across your skin, feeling your breath as you inhale and exhale - these lead to improved brain structure and cognition. There is a link between how you hold your body (body postures/yoga poses) and reduction cortisol (stress) levels (as discussed in Amy Cuddy's book Presence and her TED talk). The ability to remain calm in a stressful situation is learned bit by bit within each yoga class. We learn this by regulating the speed at which we breath in a yoga class. Controlling the breath controls the reaction of the body.
I found the research study on the affects of a yogic meditation on the cellular activity and genome levels of caregivers to be fascinating. The study indicates that a yogic meditation reduces the creation of pro-inflammatory cytokines which are produced as a result of the psychological stressors experienced by older adult caregivers. Of course, more study is needed, but the idea that mindful meditation practice could influence the body's antiviral defenses is interesting.
This quote from the paper titled "A Systematic Review of Randomised Control Trials on the Effects of Yoga on Stress Measures and Mood" puts it nicely:
"Despite methodological limitations, the large majority of the studies provide some evidence that yoga is associated with bio-logical changes in blood pressure, heart rate, cortisol or cytokine levels. It is therefore plausible that yoga may affect mood via SNSand HPA axis regulation. Further studies are required in order to confirm the preliminary findings that yoga appears to influence the stress response, and to explore the effects of yoga on the neural correlates in the context of mood changes."
A recent UCLA study published in Volume 52, Number 2 "explored the relationship between performance on memory tests and resting-state functional connectivity before and after a yoga intervention versus active control for subjects with mild cognitive impairment (MCI)." This study found that practitioners of yoga and meditation had better improvements in their visual-spatial skills than did the test group taking part in the memory enhancement training (MET) alone. Granted, the yoga used in this study was Kirtan Kriya which involves chanting, hand movements and visualization of light - but I'd venture to guess that the moving meditation qualities of any yoga practice would provide the same benefit as a Kirtan Kriya practice. Here is the full research paper for reference.
I'm looking forward to more scientific studies on the effects of yoga and its relationship to neuroplasticity (how what you think can change how your brain works). Until then, I'm going to keep rolling out my mat and breathing in for a count of five and out for a count of five.
I'm looking forward to more scientific studies on the effects of yoga and its relationship to neuroplasticity (how what you think can change how your brain works). Until then, I'm going to keep rolling out my mat and breathing in for a count of five and out for a count of five.
