We often think of stress as something that we cannot control and as something that may be ‘in our head’ and not physically affecting our bodies. However, stress (specifically chronic levels of stress) very much impact our body and cause a cascade of neural and hormonal reactions that result in unpleasant symptoms that impact our quality of life and sense of wellbeing.
For example, do you experience any of the following?
- Digestive issues like gas, bloating, constipation
- Frequent colds & flu
All of these symptoms may be the result of experiencing chronic levels of stress.
Let’s break down what the parasympathetic nervous system is and its connection to stress. The autonomic nervous system governs the functions of the body that we do not have to think about to operate. These functions include breathing, digestion, blood pressure & heart rate, among others. The two branches of the autonomic nervous system are the sympathetic nervous system and the parasympathetic nervous system.
The sympathetic nervous system is commonly referred to as our “fight, flight or freeze” system, which operates in times of high stress, much like if we were being chased by a tiger. It causes our pupils to dilate, an increase in heart rate and blood pressure, blood flow to the peripheral body and limbs, and away from the digestion organs. It also stimulates glucose release into the blood stream, which will raise blood sugar. Additionally, it releases the stress hormone adrenaline. Prolonged release of adrenaline has been shown to increase immune cells in our body that are pro-inflammatory, resulting in increased levels of inflammation . We now know that inflammation in the body is tied to many chronic diseases.
On the other hand, our parasympathetic system, known as our “rest and digest” system turns on only during times of relaxation. It has the opposite effect on the body as pupils constrict, heart rate slows, blood pressure decreases, and blood flow to the digestive tract is increased. When our parasympathetic system is activated, it results in acetylcholine being released, which has the opposite effect on our inflammatory cells that adrenaline does, resulting in a decrease in the pro-inflammatory cells .
Only one of these systems can be operating at one time. And while they both serve a purpose, our body is always striving for homeostasis, or a balance between these systems. For the vast majority of us living in our fast-paced society, we spend more of our day in our sympathetic nervous system, and therefore could use a little support to increase that parasympathetic nervous system activity.
Here are some evidence-based ways to activate and support your parasympathetic nervous system:
Slow, deep breathing
A study of medical students showed that practicing slow breathing exercises for a period of 3 months resulted in a significant increase in parasympathetic activity and a decrease in sympathetic activity compared with a group that practiced fast breathing exercises . A great way to start is to set a timer for 2-5 minutes and practice breathing in for a count of 4 and out for a count of 8 a few times a day.
As the name implies, these are herbs that have been shown to help our body “adapt” to stress. A couple of my favourites that help to balance this stress response include Withania somnifera, Rhodiola rosea, Rehmannia glutinosa, and Glycyrrhiza glabra. It is best to speak to a healthcare provider to determine which would be the best one for you, as well as the appropriate dose.
A walk in nature
Not only will going for a walk help you to get some exercise and clear your head, nature has been shown to activate the parasympathetic nervous system. A study was conducted that had the participants experience an acute stress, followed by looking at a photo of either an urban or green landscape. Looking at photos of the green landscape activated the parasympathetic nervous system in a way that the urban landscape photo did not . Let’s take this one step further and actually get outside into nature!
- Won E, Yong-Ku K. Stress, the Autonomic Nervous System, and the Innune-kynurenine Pathway in the Etiology of Depression. Curr Neuropharmacol. 2016 Oct; 14(7): 665-673.
- Pak GK, Veklumary S, Madanmohan. Effect of short-term practice of breathing exercises onautonomic functions in normal human volunteers. Indian J Med Res. 2004 Aug; 120(2):115-21.
- Van den Berg MM, Maas J, Muller R, et al. Autonomic nervous system responses to viewing green and built settings: Differentiating between sympathetic and parasympathetic activity. Int J Environ Res Public Health. 2015 Dec 14; 12(12):15860-74.