Researchers at Ohio State University, who've previously conducted landmark research on the mind-body connection, Dr. Jane Kiecolt-Glaser and her associates, conducted a study to determine the stress reduction benefits of hatha yoga, and its chemical pathways.
They compared inflammation and endocrine chemical levels, in experienced yoga practitioners and novices before during and after a restorative hatha yoga session, as well as in two control conditions.
50 healthy women 30-65 years (average age 41 years) 25 beginners (novices) and 25 experts, were exposed to each of the conditions (yoga, movement control, and passive-video control) during three visits.
The yoga session boosted participants' positive affect compared with the control conditions, but no overall differences in inflammatory or endocrine responses were unique to the yoga session. Importantly, even though beginners and experts did not differ on key dimensions, including age, abdominal fat, and heart and lung fitness, beginners’ interleukin (IL)-6 levels (an inflammatory molecule) were 41% higher than those of experts across sessions, and the odds of a novice having detectable C-reactive protein (CRP) were 4.75 times as high as that of an expert.
Differences in stress responses between experts and beginners provided one possible explanation for their very different serum IL-6 levels; experts produced less IL-6 in response to the stress than beginners, and IL-6 promotes CRP production.
The researchers concluded the ability to minimize inflammatory responses to stressful encounters influences the burden that stressors place on an individual. If yoga dampens or limits stress-related changes, then regular practice could have substantial health benefits.
Even though the groups did not differ on age, abdominal fat, heart lung fitness, the novices' interleukin (IL)-6 levels were 41 per cent higher than those of experts across sections, and the odds of a novice having detectable CRP (C-reactive protein) were almost five times as high as that of an expert. The differences in stress responses between experts and novices provided one possible mechanism for the different blood IL-6 levels. The experts produced less lipopolysccharide-stimulated-IL-6 response to the stressors than novices, and IL-6 promotes CRP production.
The ability to minimize inflammatory response to stressful encounters influences the burden that stressors place on an individual's physiology. The researchers suggested if yoga diminishes or limits stress-related change, then regular practice could have substantial health benefits.