This post was graciously hosted @ Yoga Gypsy several weeks ago.
In Chapter 8 of B. K. S. Iyengar‘s Light on Pranayama, he quotes the Bhagavad Gita (VI 17) saying, “Yoga destroys all pain and sorrow”. Nice! and this is just one of dozens of poetic and inspiring sentiments that are woven into the otherwise detailed and rigorous methods described by Iyengar for the training of the lungs, diaphragm and intercostal muscles. Although I know the training is extensive and will surely take many years to master, I can’t help wonder how much pain and sorrow, realistically, might be alleviated by the mastery of something as basic as – you know – breathing?
How might this work? I mean, pain is something that happens in your body and in your mind. How might mastery of deep and controlled breathing alleviate pain?
It turns out that there is a scientific research journal – Pain – that is dedicated to these types of questions. A recent article, “The effects of slow breathing on affective responses to pain stimuli: An experimental study” [doi:10.1016/j.pain.2009.10.001] by Alex Zautra and colleagues investigates the role of breathing in relief from chronic pain. The authors base their research on a specific neuroanatomical model of emotion and pain regulation:
The homeostatic neuroanatomical model of emotion proposes that the left forebrain is associated predominantly with parasympathetic activity, and thus with nourishment, safety, positive affect, approach (appetitive) behavior, and group-oriented (affiliative) emotions, while the right forebrain is associated predominantly with sympathetic activity, and thus with arousal, danger, negative affect, withdrawal (aversive) behavior, and individual-oriented (survival) emotions. … The homeostatic neuroanatomical model of emotion suggests that central sensitization of pain in FM patients results in part from a relative deficit of activity in the parasympathetic branch of the ANS required for down-regulation of negative emotion and pain experience.
In basic terms, the researchers suggest that if one can increase activity of the parasympathetic nervous system, then one will experience relief from pain. So they want to evaluate whether deep breathing increases activity of the parasympathetic nervous system? In Chapter 4 of Light on Pranayama (Pranayama and the Respiratory System), Iyengar provides many detailed anatomical drawings of the musculature, skeletal and neural machinery related to breathing, but unfortunately no details on the role of parasympathetic vs. sympathetic nervous systems per se. The authors however, point to a previous study that showed slow breathing increases activation of bronchiopulmonary vagal afferents and produces enhanced heart rate variability, which reflects increased parasympathetic tone – so the scientific evidence points in the right direction.
To test the notion themselves, the investigators asked a group of healthy adult females to wear a small thermal device on the thumb that could be heated and cooled to produce varying levels of moderate discomfort (pain). By asking the volunteers to experience the thermal discomfort when breathing normally vs. breathing in a slower, deeper manner, the investigators could begin to assess whether the experience of pain (a self-reported value between 1 and 11) was different between the two breathing conditions.
The results showed that the volunteers self-reported less pain (given the same amount of thermal stimulation) when performing deep, slow breathing.
Very neat. Perhaps not a surprise to yogis 3,000 years ago nor experienced yogis today, but very exciting to see how the practice of Pranayama can engage a neuroanatomical system for the relief of suffering. In a previous post on the neural stimulation of this system – and its relation to Kundalini – it has become even more clear how potent this system can be!