Briar Rose– Arthur Wardle, 1895
Falling asleep easily and sleeping through the night, now that is something to be desired. Old wisdom says you can achieve this through breathing, it only takes a little practice. It is a fact that breath regulation can have positive effects on blood pressure, heart rate, immune response, emotional stability and that it can alleviate the subtle anxiety and stress we often feel. This is at the core of pranayama yoga and because breath can be controlled consciously, unlike most body functions, it can be used to link mind and body in uniquely powerful ways. Our goal here is to learn how to use breathing to facilitate sleep and then to understand how and why it works.
Here is a very good practice that originated in antiquity. It is called 4-7-8 breathing and it goes like this:
First, remember to breathe from your diaphragm (abdominal breathing), this is crucial for relaxation.
Exhale to clear your lungs, then begin this pattern –
1. Inhale through your nose for a count of 4.
2. Hold your breath with mouth closed for a count of 7.
3. Exhale through the mouth past your tongue making a nice loud ‘sss’ sound for a count of 8.
Repeat the pattern four times as you prepare for sleep (you can do more repeats as you become used to the exercise).
That’s all there is to it.
When you practice the routine, you are training your brain and body to enter into a relaxed, resting state free of anxiety. Like any skill, in order to gain the benefit, you have to practice. Twice a day, every day, is correct at first with one session just before sleep. You may feel some benefit right away, but it will increase and new comforts will come over the next few weeks. Relaxation breathing is self-reinforcing at a neurobiological level because of its effect on memory; I will explain later. Van Morrison famously said, “And it goes out, and it comes back. It is a feeling. And when you do it, and the more you do it, it becomes a beautiful obsession.” If the goal is healthy, dependable sleep then it’s worth the effort. Andrew Weil produced this fine video demonstration.
How does deep breathing reduce stress and ease the entry into sleep?
Although there is not a complete answer to the question, it is a good bet that it involves vagus nerve stimulation. The vagus nerve (cranial nerve X) is part of the parasympathetic branch of the autonomic nervous system that works subconsciously to influence most bodily functions. It plays a huge role in the mind-body connection, taking control signals to organs in the body and reporting to the CNS the activity and state of the organs. Under most circumstances activity in the vagus nerve promotes relaxation. If you find yourself breathing slowly and deeply, feeling a sense of calm and peacefulness, you can bet the vagus is activated, enhancing digestion, increasing blood flow to the GI track, lowering heart rate, and enhancing sexual arousal. It might be useful to think of activity in the autonomic nervous system as a balance between arousal and relaxation. Stress is a condition of low vagal activation, low vagal tone, and it comes with depression, anxiety and the like. A high vagal tone comes with calmness, rest, peace and resilience. In this simple view, patterned deep breathing moves vagal tone to the high side.
The brain structures that regulate the respiratory rhythm are within the subconscious autonomic nervous system, but in the case of respiration, we also have conscious control over them. This makes respiration a portal through which breathing can impact the brain and vice versa. When you take a deep breath, relax and expand your diaphragm, the vagus is stimulated and the level of cortisol (stress hormone) in the brain goes down.
Brain imaging gives us a look into how breath affects mood. Researchers using fMRI measured focal and global brain activity during deep breathing like the kind in our exercise. They found quieting of activity throughout the limbic system (orbitofrontal, anterior cingulate, parahippocampal gyri, thalamus, hippocampus, and amygdala). Lowering of activity in these limbic structures indicates a state of calm and the very same pattern emerges with “OM” chanting.
What other cool stuff does vagus activation through breathing do?
It has been known for a long time that stimulation of the vagus nerve strengthens newly acquired memories, especially those with high emotional content. This is how it seems to work: Ascending fibers in the vagus nerve innervate brainstem neurons in the nucleus of the solitary tract (NTS). When the vagus is active, NTS neurons respond by releasing the CNS neurotransmitter nonepinephrine into brain regions that process memory, the amygdala and hippocampus. Norepinephrine plays a still mysterious role in consolidating new memories into long-term memories and in memory recall. The greater the emotional content, the more norepi. is released and the stronger the long-term memory and the easier it is to recall.
I find it fascinating that vagus nerve activation also increases the production of nerve growth factors in the CNS. Using molecular tools to measure the abundance of mRNA, it was found that vagal activation increases mRNA for BDNF and FGF in specific regions of the cortex, and decreases the message for NGF in others. These changes could, for example, stimulate neurostemcells to begin a new cycle of neurogenesis, or cause existing neurons to make new synapses and strengthen old ones. The work is at an early stage, but it makes a very strong statement about the importance of the brain-body connection and how it might be strengthened by practice based on yogic breathing.