Yoga Therapy is a way of working one to one with the individual. In moving ahead in this field and making it more accessible to the community, it can be valuable to understand the biomedical and biopsychosocial aspects of mind-body medicine and the latest research in the field. BIYOME makes the latest research more accessible to yoga teachers and yoga therapists. We break it down into six (6) evidence-based research findings. This breakdown all makes Yoga, Yoga Therapy and Mindfulness Meditation a proven way of bringing the individual back to health by entering into a state of yoga and Meditation.
Mindfulness Meditation, based on Buddhist practices, is the practice of bringing one’s focus to the breath, body and present moment. Recently, much research has studied the innumerable positive benefits of this practice that delivers a more peaceful and tranquil body and mind.
Through the research behind the six conduits of a connected mind, one can understand how truly complex and interconnected all bodily systems are and how mindfulness meditation can help bring them all to a healthier balance.
These six conduits are as follows:
- The vagus nerve
- The heart-brain connection
- Heart rate variability (HRV)
- The hypothalamic-pituitary-adrenal (HPA) axis
- The gut-brain axis and
- Psychoneuroimmunology
This article will briefly explain each conduit, describing its interconnectedness and relation to mindfulness meditation and yoga therapy.
The Vagus Nerve
Initially, the importance of the vagus nerve is discussed. The vagus nerve is the tenth cranial nerve and interacts with the digestion, immune and cardiovascular systems (Ardell et al., 2015; Brack et al., 2004; Chang et al., 2015; Maier et al., 1998). The nerve plays a significant role in relaying information occurring in the body to the brain, with 80% of its fibres acting as ascending sensory neurons (Chang et al., 2015). For example, the brain receives status updates of the immune system’s cytokines through vagus nerve stimulation (Maier et al., 1998). Meditation on breathing is also highly intertwined with the processes of the vagus nerve as the significant source of all nerve innervations in the lungs derive from the vagus nerve (Chang et al., 2015). Vagal tone has also been shown to significantly increase compared to control of placebo through the practice of yoga (Khattab et al., 2007). This connection likely explains many of the relationships breathing, yoga, and Meditation have on the multitude of bodily systems connected to the vagus nerve.
The Heart-Brain Connection
One such system is the all-important heart. The interaction between the heart and brain is highly complex, involves many neurons and has the most communication pathways to the brain compared to any other organ in the body (Cameron, 2002). The vagus nerve plays a vital role in autonomic nervous system (ANS) interaction with the heart. Stimulating the vagus nerve has been shown to affect heart rate in multiple studies (Ardell et al., 2015; Brack et al., 2004; Maier et al., 1998). Not only can the brain affect the heart, but the heart can affect our brain and emotions. Studies have shown that heart rate can determine our emotional experience.
An example of this is seen in panic disorders, where physiologic aspects of the disease are created by cardiac arrhythmias (Mccraty et al., 2009). The heart and brain can affect each other, and the harmony between both is of extreme importance. Heart health has been shown to be improved considerably through yoga by causing a reduction in heart rate, blood pressure and BMI (Sivasankaran et al., 2006). Meditation studies have shown that heartbeats and brain waves synchronize during the practice (Montoya et al., 1993), suggesting mindfulness meditation can bring harmony to the body and mind.
Heart Rate Variability (HRV)
Another critical aspect of the heart-brain relationship is heart rate variability (HRV). HRV is a measure of beat-to-beat variability performed by the heart. HRV is regulated by the autonomic nervous system (ANS) and primarily mediated through the vagus nerve through parasympathetic nervous system (PNS) activity (Krygier et al., 2013). The capability of variability is indicative of the body’s ability to adapt to environmental demands, regulate emotions, and be reduced in patients with cardiovascular disease (Krygier et al., 2013). In other words, an increase in PNS tone can have positive influences on HRV, thereby increasing heart and body health. Multiple studies have shown that this increase in PNS activity and, consequently, HRV can be achieved through Meditation (Nesvold et al., 2012; Phongsuphap et al., 2008; Wu & Lo, 2008). Additional benefits of Meditation have been found, including increasing baroreflex sensitivity through the exact mechanisms that improve gas exchange within the lungs (Phongsuphap et al., 2008). A decreased HRV is a symptom of depression and can be alleviated through yoga (Karavidas et al., 2007; Khattab et al., 2007; Streeter et al., 2018).
The Hypothalamic-Pituitary-Adrenal (HPA) Axis
Clearly, the heart is greatly influenced by the vagus nerve, and therefore function can be improved through mindfulness. However, this is not the only system affected. The Hypothalamic-Pituitary-Adrenal (HPA) Axis is also greatly affected. The HPA axis can be thought of as one of the main branches of the body’s stress system. The ANS comprises the sympathetic nervous system (“fight or flight response”) and the parasympathetic nervous system (“rest and digest response”). They are used in our body’s system for survival. The ANS system is the neuronal side of our stress system, and the HPA axis is the hormonal side of the system (Pascoe et al., 2020). The brain’s hypothalamus secretes corticotropin-releasing factor (CRF) when the body is stressed. CRF triggers the pituitary gland to produce and release adrenocorticotropic hormone (ACTH). ACTH stimulates the release of cortisol, which is the stress hormone that affects the rest of the body (Geiser, 1989). The overuse of this system can have many negative consequences on bodily health.
ACTH decreases Natural Killer (NK) cells which fight cancer, cortisol decreases T cell activity and reduces lymphocyte response in the immune system (Geiser, 1989). In short, chronic stress is a strong indicator of poor health and increases the risk of illness (Ader & Cohen, 1993; Cohen, Sheldon, Williamson, 1991; Geiser, 1989). Multiple research studies have shown that yoga decreases these stress hormones such as cortisol, catecholamines and renin-angiotensin (Riley & Park, 2015). It is a practice that can significantly reduce stress in life while increasing overall bodily health.
Psychoneuroimmunology
The relationship of mind and body in terms of immune function has developed into the field of psychoneuroimmunology. Psychoneuroimmunologists study the relationship between the emotional state of mind and how it affects immune function and vice versa. Meditation can counteract these effects by lowering cortisol and other stress-related hormones while increasing NK cells and leukocytes within the immune system (Moraes et al., 2018). Meditation is one of the most potent and natural tools humans have to combat chronic stress and anxiety. Doing so will not only heal the mind and make it feel better but also make the body healthier and less prone to illness.
Gut-Brain Connection
The gut and brain also share a deep connection, affecting the health of both mind and body. A healthy gut wall selectively allows nutrients into our body while excluding harmful molecules such as pathogens. Stress can drastically affect gut microbiota health, thereby increasing the number of pathogens that make it inside of our body and can cause illness (Househam et al., 2017). Yoga and Meditation alleviate stress through present moment awareness, and both can aid in preventing illness from occurring. A clinical example of this is Meditation and yoga to alleviate symptoms of irritable bowel syndrome (Kavuri et al., 2015; Schoultz et al., 2015).
We invite you to learn more about your health…
The body and mind interact in a complex dance of physiologic balance. Too much stress, for example, can have many negative consequences harming the cardiovascular system, immune system and digestive system. Furthermore, when one system is unhealthy, consequences will also befall the others. The six conduits of a connected mind remind us that through Meditation and yoga, we can gain better insight and balance for our bodily systems, promoting more excellent health and wellbeing.
AT BIYOME, we study the six conduits of a connected mind and body in our yoga and meditation teacher training.
Ask us more about how you can learn with us today.
Meditation as Medicine ~ 6 Mind Body Conduits (live-streamed recording)
References
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Ardell, J. L., Rajendran, P. S., Nier, H. A., KenKnight, B. H., & Armour, J. A. (2015). Central-peripheral neural network interactions evoked by vagus nerve stimulation: functional consequences on control of cardiac function. American Journal of Physiology-Heart and Circulatory Physiology, 309(10), H1740–H1752. https://doi.org/10.1152/ajpheart.00557.2015
Brack, K. E., Coote, J. H., & Ng, G. A. (2004). Interaction between direct sympathetic and vagus nerve stimulation on heart rate in the isolated rabbit heart. Experimental Physiology, 89(1), 128–139. https://doi.org/10.1113/expphysiol.2003.002654
Cameron, O. G. (2002). Visceral Sensory Neuroscience: Interoception. In Oxford University Press. Oxford University Press.
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