THE VAGUS NERVE - CREATING BALANCE FROM CHAOS
Our greatest potential is only fully realized in a state of balance. Yet, the era in which we currently live is anything but balanced.
This lack of equilibrium is epitomized by the high prevalence of chronic stress that shows no regard for age, gender, ethnicity or income bracket. Although technological advancements have made many tasks and activities more efficient, we have less time. While we have access to more information and knowledge than ever before in history, we have less clarity. Although repetitive routines, oppressive structures and tedious procedures are ever-present in all that we do, we have no sense of control.
The combination of limited time, a relentless bombardment of stimuli and lack of control in our lives (together with many other modern day nuances) repeatedly trigger the ‘stress response’ – a complex biological state, which was once necessary for survival and adaptation to change.
Activated sporadically and in the appropriate circumstances, the stress response is energizing and allows us to adjust, succeed and thrive. However, activated continuously, a very different picture emerges – that of strain, disease and premature aging.
Typically, a stressful situation evokes an astonishing interplay between two powerful hormones - adrenaline and cortisol. These hormones have vastly different roles, yet are both produced by the adrenal glands, which are located just above the kidneys. Initially, the brain, perceiving adverse circumstances, will trigger the release of adrenaline. This powerful hormone mobilizes our immune system, elevates blood pressure, as well as increases blood and oxygen supply to the limbs, brain, heart and lungs. This biological shift can be costly in the long-term in that it disrupts digestive, reproductive and regenerative functionality.
Should the stressor persist for more than a few minutes, the hormone cortisol will flood the system. Cortisol in the short-term has strong immune-regulating effects. It assists with the maintenance of blood sugar levels, reduces inflammation and positively influences metabolism.
In a healthy state, we can shut down this necessary biological adaptation as quickly as it was initiated. However, with aging, persistent activation, poor lifestyle habits and poor health, the cortisol effect can remain in our systems long after the initial threat (perceived or real) has been removed.
The long-term effects of elevated cortisol are destructive to say the least - immune suppression, immune dysregulation, bone demineralization, metabolic slow down, insulin resistance, weight gain, anxiety, depression, sleep disorders, genetic damage and most concerning, significant brain atrophy.
The challenge within the context of elevated stress hormones and the associated biological burden is that psychological strain is by no means the only trigger. Other significant activators include genetic alterations, lack of sleep, inadequate rest, poor diet and nutritional deficiencies, lack of exercise, over exercising, environmental pollution and even social isolation (a study by English researchers published in the journal Psychoneuroendocrinology showed that living alone was strongly associated with higher cortisol levels and an elevated stress profile).
The robust ability to rapidly shut down the ‘stress response’ is a vital biological attribute within the context of health and longevity. This requires optimal tone, proper function and most importantly regular stimulation of the vagus nerve. The vagus nerve is one of the longest and most influential in the body. It exits the skull just behind the ears and descends vertically along the front of the throat through the chest cavity and continues down into the abdomen. It is the direct interface between the brain and key organs and systems of the body most notably the heart, lungs and digestive tract. This ‘wandering’ nerve operates far below the level of our conscious minds and although its primary role is synchronicity between the body and the brain, its best recognized attribute is that of calming the body following the ‘fight-or-flight’ state induced by adrenaline.
Medical researchers have long known that the stronger ones vagal tone (which can be measured by an electrocardiogram), the quicker the body can normalize itself following a perceived threat or stressful event. This may explain why some people are biologically immune to on-going stress, whilst others become overwhelmed and ill from even the slightest upset. Research shows that low vagal tone is associated with a chaotic biological state, culminating in significant immune dysregulation and chronic inflammation.
Research pioneered largely by Kevin Tracey, a world-renowned professor of neurosurgery and molecular medicine, has shown the vagus nerve to be a master controller of inflammation and immune regulation within the body.
According to Tracey, the vagus nerve interfaces with spleen signalling specialized immune cells (T-cells) to release acetylcholine (a type of chemical messenger), which in turn stimulates cells called macrophages (a type of white blood cell) to shut down the production of a key proinflammatory chemical known as TNF. Dysregulation of TNF is associated with numerous diseases including Alzheimer’s, depression, cancers and inflammatory disorders of the digestive system. Normally, with a proper vagal tone and frequent stimulation, TNF is properly moderated and health promoted.
In recent years, there has been a wave of research showing the effectiveness of vagal stimulation (using an electrical stimulator) in a variety of clinical settings. A 2016 multinational study published in the journal Proceedings of the National Academy of Sciences showed how vagus nerve activation could successfully treat Rheumatoid arthritis. Recently, French researchers discovered that vagus nerve stimulation could be used to successfully manage Crohns disease (an inflammatory bowel disease) and even result in remission. An extensive 25-year review of the literature surrounding vagus nerve stimulation and neurological health outcomes published in Neuroscience & Biobehavioral Reviews showed that vagus nerve stimulation is successful in improving symptoms of Alzheimer’s disease as well as in enhancing memory and cognition in healthy individuals.
Knowing the immense value that this nerve holds in managing stress and promoting health, the question is, “What can one do to ensure optimal tone and proper functionality?”
Incredibly, there are countless activities and practices that will stimulate the vagus nerve! I have selected a few of the more effective approaches.
The practice of Yoga has been growing in popularity in recent years – and with good reason. In addition to the numerous benefits attributed to yoga such as increased flexibility, balance, coordination and strength, research shows that yoga increases vagal tone and reduces cortisol.
In 2016, Australian researchers published a review involving 59 studies, showing that that yoga improved vagal tone during practice. The review also found that regular yoga practitioners had increased vagal tone at rest compared to non-yoga practitioners.
Controlled breathing exercises
Numerous studies have shown that slow controlled breathing exercises increase vagal tone, leading to the reduction in the stress response and increasing baroreflex sensitivity. Baroreceptors are super-specialized pressure gages that are strategically located in arterial walls (aortic arch and carotid sinus) that communicate with the vagus nerve in response to rising blood pressure. Their role is to signal the vagus nerve to lower heart rate and control the fight-or-flight response.
Selecting a breathing technique can be a little challenging, considering there are so many to choose from. Interestingly, according to a 2013 study published in the Journal Evidence-Based Complementary and Alternative Medicine, most of these techniques elicit the identical biological outcome. This said, based on studies published in the European Respiratory Journal and journals Hypertension and Circulation, it appears that 5-6 breaths per minute is an ideal means of activation of the vagus nerve.
Dr Andrew Weil has a simple technique (4:7:8) that can be used several times a day.
- Sit up straight
- Place the tip of your tongue up against the back of your front teeth. Keep it there through the entire breathing process
- Breathe in silently through your nose for the count of four
- Hold your breath for the count of seven
- Exhale through your mouth for the count of eight, making an audible “woosh” sound
That completes one full breath. Repeat the cycle another three times, for a total of four breaths.
‘Light’ massage and osteopathic manipulation
In a 2014 study published in the Journal of Clinical Neuroscience, Canadian researchers found that light massage on the carotid artery could stimulate the vagus nerve to such an extent that it could supress seizures in those who were predisposed to them.
Pioneering work by French osteopaths (Jean-Pierre Barral and Alain Crobier) over the last two decades has seen the emergence of a hybrid field of manual therapy, sometimes referred to as visceral osteopathy. Practitioners with this training have a unique skillset, in that they are expertly trained in interfacing with the vagus nerve at various locations within the body. In my experience, this is one of the most effective means of vagal stimulation and offers tremendous value within the context of health promotion and stress resilience.
Other activities that stimulate the vagus nerve include prayer, communal singing, reflexology, acupuncture, sunlight exposure, meditation, intermittent fasting and even laughter.BACK