PRANAMAYA KOSHA RELEVANT RESEARCH

Mudra. Authors of a 2018 paper examining mudra suggest that it may function similarly to reflexology, in that by “applying light pressure to…areas of the hand,” corresponding brain regions are activated (Kumar et al., 2018, p. 2). These researchers utilized a novel investigative technique called Electrophotonic Imaging (EPI) to evaluate the differences in test (prana mudra) and control (meditation) groups. One of the main questions yet unanswered, they admit, “is to understand physical and psychological processes revealed by the [EPI] measurement” (p.3). Their interpretation of the EPI data revealed statistically significant difference between the two groups when prana mudra was sustained for more than 20 minutes. I have no way to evaluate such findings, though I do appreciate that researchers are actively discerning novel ways to evaluate processes of the subtle body.

More immediately relevant might be research that explored respiratory, heart rate, or mood changes following the deployment of a mudra practice, but perhaps that is ultimately unnecessary. We modern yogis are often seekers of some externally verifiable truth to support our first-hand experience. I advocate the scientific method, and the research born from it. I’m also committed to using my direct experience as a teacher. I would not claim (as some do) that gesturing the hands in a certain way is curative for physiological and psychological ailments—I don’t have that direct experience. I have experienced the way taking my hands in certain shapes directs the mind and body to a more pacified or energized state of being. That is the lens through which we’ll explore mudra as a tool in this chapter. I’ll leave the “hows” and “whys” of subtle body function to researchers and their EPI measurement. Suffice it to say that mudra is a complex practice, and outlining it fully, or explaining its mechanisms is beyond the scope of this work. If you feel called to dive in, Joseph Le Page & Lilian Aboim’s Mudras for Healing and Transformation (2014) is considered essential reading by many yoga therapists.

Kumar, K. S., Srinivasan, T. M., Ilavarasu, J., Mondal, B., & Nagendra, H. R. (2018). Classification of electrophotonic images of yogic practice of mudra through neural networks. International journal of yoga, 11(2), 152–156. https://doi.org/10.4103/ijoy.IJOY_76_16

Mantra. Two recent reviews examine current research into the efficacy of mantra-based meditation (MBM). Through the process of systematic review, Álvarez-Pérez et al. (2022) evaluates current scientific evidence on the efficacy and safety of mantra-based techniques as tools for managing mental health symptoms. They find that in the areas of anxiety, depression, stress, post-traumatic stress, and mental health related quality of life, MBM had small to moderate effects. Tseng (2022) also reviewed the literature regarding the scientific evidence in support of mantra-based practices and found strong evidence in support of the technique in relieving stress and reducing hypertension. The evidence was weaker in regard to the reduction of anxiety, or the improvement of immunity. Both studies cite the challenges surrounding the heterogeneity of research methods, and call for a more comprehensive study of MBM, particularly in populations with psychiatric diagnoses.    

Álvarez-Pérez, Y., Rivero-Santana, A., Perestelo-Pérez, L., Duarte-Díaz, A., Ramos-García, V., Toledo-Chávarri, A., Torres-Castaño, A., León-Salas, B., Infante-Ventura, D., González-Hernández, N., Rodríguez-Rodríguez, L., & Serrano-Aguilar, P. (2022). Effectiveness of mantra-based meditation on mental health: A systematic review and meta-analysis. International journal of environmental research and public health, 19(6), 3380. https://doi.org/10.3390/ijerph19063380

Tseng A. A. (2022). Scientific evidence of health benefits by practicing mantra meditation: narrative review. International journal of yoga, 15(2), 89–95. https://doi.org/10.4103/ijoy.ijoy_53_22

While the body of pranayama-related research is growing, there are still only a handful of quality studies investigating the effects of specific yogic breathing practices. Therefore, it’s difficult to say that pranayama “X” produces a particular statistically significant result. There is research on the pacifying and stimulating effects of various modes of breathing that are associated with specific techniques, and we’ll explore those findings.

Relevant Pranayama Research.

The wide range of techniques that fall under the pranayama umbrella have been associated with similarly extensive benefits, as a 2006 literature review (Jerath, Edry, Barnes & Jerath) suggests: improvement in cardiovascular and pulmonary function; improvement in grip strength; increase in neuroplasticity; improvement across psychological profiles; improvement in digestive function and general immune function; increase in autonomic nervous system function and overall improvement in parasympathetic activation. A 2020 systematic review (Jayawardena et al.) of 18 studies demonstrated pranayama’s significant positive effect on cardiorespiratory functions in patients with various respiratory disease as well as forms of cancer. Pulse rate, systolic*

*Side Note: Systolic pressure, the upper number in the blood pressure ration, reflects the force produced by the heart when pumping blood outward to the body. Diastolic pressure, the denominator, represents the pressure in the blood vessels when the heart is at rest. While both are important, higher systolic blood pressure is associated with higher risk of cardiovascular dysfunction.

blood pressure, and respiratory function measurements improved along with quality of life.

A 2014 study (Sharma et al.) evaluated the effects of slow (i.e., alternate nostril breathing) and fast pranayama (i.e., kapalabhati and bhastrika) on cognitive function. In both groups, executive function, perceived stress and reaction time improved, though the group practicing fast pranayama techniques demonstrated greater reduction in reaction time. If your work with your client involves the improvement of cognitive function, as it often might with a fatigued and stressed new mother, you might explore faster paced techniques so long as the excitatory impact doesn’t undermine the benefits of parasympathetic activation, which may be your client’s foremost need.

A 2022 study (Jagadeesan et al., 2022) evaluated the effect of bhramari pranayama on forty-two COVID-19 patients in home isolation. Researchers determined that the calming breath technique performed by mimicking the sound of a buzzing bee on exhalation significantly reduced depression, anxiety, and stress, and improved quality of sleep and quality of life. A 2020 study (Novaes et al.) used functional magnetic resonance technology (fMRI) to examine the impact of bhastrika pranayama—a more forceful form of breath regulation relative to bhramari involving active inhales and exhales—on measures of clinical stress and anxiety. The brain scans revealed that pranayama practice modulates the activity of brain regions involved in emotional processing. Though researchers acknowledge that their analyses were “preliminary and exploratory,” they suggest their findings provide evidence that four weeks of bhastrika practice “significantly reduce the levels of anxiety and negative affect, and that these changes are associated with the modulation of activity and connectivity in brain areas involved in emotion processing, attention, and awareness” (p.1).

How does the long, slow, and deep breathing associated with certain pranayama techniques work? Interested in the mechanics of pranayama at the cellular level, researchers hypothesize that “voluntary slow deep breathing functionally resets the autonomic nervous system through stretch-induced inhibitory signals” and the synchronization of “neural elements in the heart, lungs, limbic system and cortex” (Jerath, Edry, Barnes, & Jerath, 2006, p.1). The end result of this activation, inhibition, and synchronization is increased parasympathetic dominance, and decreased blood pressure, heart rate, and oxygen consumption. A 2018 study (Zaccaro et al., 2018) determined that slow breathing techniques impact the autonomic and central nervous systems (ANS and CNS), as well as psychological states. The “psychological/behavioral outputs related to the changes in the ANS and CNS are “increased comfort, relaxation, pleasantness, vigor and alertness, and reduced symptoms of arousal, anxiety, depression, anger, and confusion” (p. 1). As the authors of a 2017 paper suggest, it’s not that slow breathing practice necessarily minimizes sympathetic activity, but rather, it appears that slow breathing works on the system to enhance “autonomic reactivity to physical and mental stress” (Russo, Santarelli, & O'Rourke). Slow breathing facilitates the dominance of the parasympathetic state while supporting the system’s capacity to up-regulate when necessary.

The suggestion that breath, nervous system function, and emotional experience are interrelated dovetails with the findings of two complementary studies exploring the relationship between emotion and breath, as reported in a 2010 article (Philippot, Chapelle & Blairy 2010). In the first study, participants were asked to produce an emotion (joy, anger, fear, or sadness) and then to describe the way the emotion impacted their breathing. “Results revealed that breathing patterns reported during voluntary production of emotion were (a) comparable to those objectively recorded in psychophysiological experiments on emotion arousal, (b) consistently similar across individuals, and (c) clearly differentiated among joy, anger, fear, and sadness” (p. 1). A second study built on the foundation of the first evaluated the effect of specific breathing patterns—those identified in the first study—on “emotional feeling state.” Researchers found that breath manipulation produced “significant emotional feeling states that were differentiated according to the type of breathing pattern” (p.1) These studies reveal that “bottom up” breathing patterns and “top down” emotional processing intersect; each is an entry point for change.

Jayawardena, R., Ranasinghe, P., Ranawaka, H., Gamage, N., Dissanayake, D., & Misra, A. (2020). Exploring the therapeutic benefits of pranayama (yogic breathing): A systematic review. International journal of yoga, 13(2), 99–110. https://doi.org/10.4103/ijoy.IJOY_37_19

Jerath, R., Edry, J. W., Barnes, V. A., & Jerath, V. (2006). Physiology of long pranayamic breathing: neural respiratory elements may provide a mechanism that explains how slow deep breathing shifts the autonomic nervous system. Medical hypotheses, 67(3), 566–571. https://doi.org/10.1016/j.mehy.2006.02.042

Novaes, M. M., Palhano-Fontes, F., Onias, H., Andrade, K. C., Lobão-Soares, B., Arruda-Sanchez, T., Kozasa, E. H., Santaella, D. F., & de Araujo, D. B. (2020). Effects of yoga respiratory practice (bhastrika pranayama) on anxiety, affect, and brain functional connectivity and activity: A randomized controlled trial. Frontiers in psychiatry, 11, 467. https://doi.org/10.3389/fpsyt.2020.00467

Philippot, P., Chapelle, G., & Blairy, S. (2010). Respiratory feedback in the generation of emotion. Cognition and Emotion, 16(5), 605–627. 

Zaccaro, A., Piarulli, A., Laurino, M., Garbella, E., Menicucci, D., Neri, B., & Gemignani, A. (2018). How Breath-Control Can Change Your Life: A Systematic Review on Psycho-Physiological Correlates of Slow Breathing. Frontiers in human neuroscience, 12, 353. https://doi.org/10.3389/fnhum.2018.00353

Nadi Shodana: Relevant Research. Yogic philosophy suggests that variation stimulates the nervous system in a slightly different way; current science is beginning to explore this supposition. We now verifiably know what ancient yogis understood through self-study—that the nostril dominance in breathing cycles periodically throughout the day. This “nasal rhythm” is characterized by “alternating congestion and decongestion of opposite nostrils” (Telles et al., 2017, p.2). This cycling is related to the function of the central and autonomic nervous systems. The open or expanded nostril is associated with sympathetic dominance, while parasympathetic dominance is associated with the partial or completion closure of the nostril on the contralateral side.

While yogic philosophy suggests that right-side nostril breathing is activating, and left side nostril breathing is pacifying, science is revealing that the process is a little more complex. A 2022 study investigating the immediate effects of employing the breathing techniques for five minutes found that while no significant difference was revealed between right and left side dominant breathing patterns, both techniques decreased heart rate (Malhotra, et al., 2022). Extended practice (more than 45 minutes) reveals differences in the effect on the nervous system. Right side uni-nostril breathing caused increased in peripheral vasoconstriction, systolic blood pressure, and heart rate, all of which suggest sympathetic activation (Telles, Nagarathna, Nagendra,1994). Left side uni-nostril breathing resulted in reduction of blood pressure (Raghuraj & Telles, 2008).

Researchers have also demonstrated measurable effects of alternate nostril breathing. Eighteen minutes of alternate nostril breathing has been found to lower systolic and diastolic blood pressure (Telles et al., 2013). Examination of the brain with electroencephalogram, or EEG, revealed that alternate nostril breathing decreased power and amplitude of theta and beta band brain waves (Telles et al., 2017). Given that these brain waves are associated with increased mental activity and arousal, the study authors suggest that this finding reveals that alternate nostril breathing decreases mental arousal, resulting in the experience of increased calm. EEG of the brains of individuals tasked with “sitting quietly,” on the other hand, revealed greater arousal and increased activation, suggesting that the “mental state during quiet sitting may be comparable to the state of mind wandering and self-referential processing” (p.9).

Malhotra, V., Srivastava, R., Parasuraman, P., Javed, D., Wakode, S., Thakare, A., Sampath, A., & Kumari, A. (2022). Immediate autonomic changes during right nostril breathing and left nostril breathing in regular yoga practitioners. Journal of education and health promotion, 11, 280. https://doi.org/10.4103/jehp.jehp_343_22

Raghuraj, P, & Telles, S. (2008). Immediate effect of specific nostril manipulating yoga breathing practices on autonomic and respiratory variables. ApplPsychophysiolBiofeedback,13:65–75.

Telles, S., Gupta, R. K., Yadav, A., Pathak, S., & Balkrishna, A. (2017). Hemisphere specific EEG related to alternate nostril yoga breathing. BMC research notes, 10(1), 306. https://doi.org/10.1186/s13104-017-2625-6

Telles S, Yadav A, Kumar N, Sharma S, Visweshwaraiah NK, Balkrishna A. (2013). Blood pressure and purdue pegboard scores in individuals with hypertension after alternate nostril breathing, breath awareness, and no intervention. Med Sci Monit,19, 61–66. doi: 10.12659/MSM.883743.

Telles S, Nagarathna R, Nagendra HR. (1994) Breathing through a particular nostril can alter metabolism and autonomic activities. Indian JPhysiolPharmacol., 38, 133–7. 

Sheetali & Sitkari, or Breath that Cools: Relevant Research. Research finds both techniques to be effective in reducing blood pressure and “shifting autonomic balance in favor of parasympathetic dominance” (Shetty et al., 2017, p. 8). Only one study has been conducted evaluating whether the cooling benefits associated with these techniques are born out through physiological measures (Telles et al, 2020).  Seventeen healthy male volunteers between the ages of nineteen to twenty-five were assessed throughout four different techniques: sheetali pranayama, sitkari pranayama, breath awareness and quiet lying. Surface body temperature and metabolic variables were assessed before, during, and after the eighteen-minute practices. Instead of cooling the body, sheetali and sitkara pranayama actually produced metabolic arousal and increased body temperature relative to the other techniques. This finding is interesting, and bears validation through additional, larger studies. I wonder, then, about the experiential data I and so many others have gathered. Are these techniques useful in the way that drinking a hot cup of chai on a warm day in India is thought to also be cooling? Research suggest that the combination of external and internal heating forces the body to regulate temperature by triggering the sweat response, the effect of which can be cooling. Perhaps the same principle applies to these cooling breath techniques.     

Shetty, P., Reddy B, K. K., Lakshmeesha, D. R., Shetty, S. P., Kumar G, S., & Bradley, R. (2017). Effects of sheetali and sheetkari pranayamas on blood pressure and autonomic function in hypertensive patients. Integrative medicine (Encinitas, Calif.), 16(5), 32–37.

Telles, S., Gandharva, K., Sharma, S. K., Gupta, R. K., & Balkrishna, A. (2020). Body temperature and energy expenditure during and after yoga breathing practices traditionally described as cooling. Medical science monitor basic research, 26, e920107. https://doi.org/10.12659/MSMBR.920107