What is the vagus nerve
The vagus nerve is the most important nerve linked to the activation of the rest-and-digest nervous system (parasympathetic nervous system). Vagus nerve connects the brain to multiple internal organs (e.g. lungs, gut, liver, heart, kidneys, and gallbladder). As the vagus nerve is a broad network of nerves reaching all around the body, it’s affecting the mental and physical health holistically. It has an important role in digesting food, sleep, cellular recovery, and calmness.
Importantly, the vagus nerve is a two-way road; it delivers signals to the brain from the internal organs but also delivers messages from the organs to the brain. For example, it detects gut hormone and nutrient status and signals the brain about satiety or hunger. It also monitors the hormone levels in the brain and activates or deactivates the functions of internal organs. For example, when the brain is informed about inflammation, it sends a signal to the vagus nerve to initiate an immune response.
Vagus nerve is the most important nerve which controls biological stress and thus it can inhibit oxidative stress, inflammation, and symptoms of chronic diseases such as irritable bowel syndrome.
Vagus nerve activation
- Increase relaxation, calmness, and contentment
- Treats depression (S)
- Improve digestion, gut flow, gastric juices, and stomach acidity
- Stimulates saliva production and flow
- Increase dopamine signaling (S)
- Slow down the heart rate
- Lower inflammation via the cholinergic anti-inflammatory pathway
- Lower blood pressure
- Increase GABA signaling in the brain
- Constrict pupils
- Regulates insulin secretion and homeostasis in the liver
- Stimulates neurons in the brain which produce oxytocin
How to activate the vagus nerve
1) Deep breathing (slow abdominal breathing)
Vagus Nerve can be activated by taking deep breaths. Deep breathing means the type of breathing which engages your belly. It’s also called slow abdominal breathing or diaphragmatic breathing.
Deep breathing activates receptors that detect blood pressure, which is connected to the heart via the vagus nerve. When you take deep breaths, the vagus nerve tells the heart to beat slower. This is why deep breathing is also calming and relaxing. This might also be one underlying reason behind the stress-relieving effect of meditation. (S)
To activate the vagus nerve, inhale and simultaneously visualize that you are filling up the upper part of the abdomen like a balloon. Make it a long, mindful inhalation but without tensing your body. After the inhalation, stop and exhale slowly imagining how your belly button drops towards your spine.
2) Improving the gut microbiota
Vagus nerve is connected to the gut and the condition of the gut microbiome can significantly affect the activity of the vagus nerve. Gut problems such as IBS or IBD is linked to the low activity of the vagus nerve, whereas Improving gut microbiome can stimulate the vagus nerve, increase mood, and improve stress resiliency.
Improve gut microbiome by adding these foods into your diet:
- Probiotics (e.g. Lactobacilli and Bifidobacteria)
- Prebiotics (e.g. chicory root, artichokes, garlic, dandelion, asparagus, and banana)
- Fermented foods (e.g. sauerkraut, kombucha, kimchi, and fermented teas)
- Polyphenols (e.g. dark/raw chocolate, blueberries, broccoli)
- High-fiber foods (berries, psyllium, broccoli, soaked almonds)
3) Loving-Kindness meditation, hugging, connecting with others
It has been shown that experiencing positive social connection activates the vagal nerve. For example, contemplating on positive emotions, loving attitude, compassion, and kindness with Loving-Kindness meditation can increase vagal tone. The meditation is also shown to increase the frequency of felt positive emotions, and feelings of social connectedness, and improve immunity. (S) Another way to connect with people, activate the vagus nerve and relax with long hugs. This also promotes neurotransmitter oxytocin which boosts the immune system (oxytocin-neuron-immune network).
4) Singing, humming, om-chanting
Vagus Nerve is connected to the vocal cords and inner ear. When you hum or chant your vocal cords activate which also activates the Vagus Nerve.
5) HRV training
Measures of Heart Rate Variability and Vagus Nerve activity correlates .88.(S)
Heart Rate Variability Training means using an HRV detecting sensor (such as a Bluetooth belt) and App on a smartphone to measuring real-time HRV and using breathing techniques such as belly breathing and extended exhalations to try to increase HRV.
6) Electrical Vagus Nerve Stimulation
Electrical Vagus Nerve Stimulation is a medical treatment that involves the use of a vagus nerve stimulator device that gets implanted under the person’s collarbone. The method is FDA-approved to treat epilepsy and depression.
VNS has also shown to help in inflammatory disease conditions such as sepsis, lung injury, rheumatoid arthritis (RA), and diabetes. It is also being used to control pain in fibromyalgia and migraines. (s)
7) Cold Exposure or washing face/neck with cold water
Cold exposure such as cold showers or ice bathing activates the vagus nerve because your body begins to adjust to the cold. The consequence is that the body’s sympathetic nervous system activity declines and parasympathetic nervous system activity increases. (S)