How Does the Vagus Nerve Impact our Health?

Have you ever wondered how the vagus nerve impacts our health? You might be surprised to find out just how far reaching its impact is!

“Vagus” is the Latin word for wandering, which is highly appropriate given that it is the longest cranial nerve. From its origin in the brain stem, the vagus nerve branches out, connecting to major organs along its way to the colon. It oversees a wide range of vital bodily functions.

The vagus nerve is connected to the parasympathetic nervous system, the ‘rest and digest’ arm of the autonomic system, which controls unconscious actions, such as breathing and digestion. If the vagus nerve is stimulated in times of stress, it sends a message to our body letting us know that we can relax. Long term benefits can follow in relation to mood, pain management, and overall wellbeing and resilience.

How does the vagus nerve work?

A two way communication link is formed between the gut and the brain via the vagus nerve. Information is sent from the gut, liver, heart, and lungs to the brain. The gut is a particularly sensitive organ as the balance of microorganisms in the gut, known as the microbiota, and the brain, communicate via the microbiota-gut-brain axis. The vagus nerve senses the microbiota and the state of the organs and sends this Information from the gastrointestinal tract to the brain. In turn, the central nervous system in the brain generates an appropriate response.

What does the vagus nerve influence and oversee in the body?

• Regulation of heart rate and blood pressure
• Digestion and taste
• Appetite control, satiety and weight gain
• Reflex actions, including coughing, swallowing, sneezing and vomiting 
• Modulation of the Immune response and inflammation
• Control of mood and promotion of wellbeing, including the release of the ‘cuddle’ hormone oxytocin

What can negatively impact on vagus nerve health?

Stress is a key inhibitor of healthy vagus nerve functioning.  At the same time stress ramps up the production of the stress hormones adrenalin and cortisol as part of the stimulation of the sympathetic nervous system or ‘fight or flight’ response.

We know that the balance of bacteria in the gut microbiota can also influence the action of the vagus nerve. Specific bacteria have the capacity to negatively affect the brain. For instance, the presence of Campylobacter jejuni bacteria can increase anxiety levels (Goehler et al. 2005).

Chronic intake of high fat foods and high carbohydrate foods reduce the sensitivity of the vagus nerve, dampening our ability to feel satiated and so encouraging over eating.

What can go wrong if the vagus nerve is not functioning well?

A reduction in vagus nerve response can lead to an inability to respond well to stress in our lives. It can also corollate with increased levels of mood disorders, anxiety, depression and brain fog. We can see an increase in inflammatory conditions such as inflammatory bowel disease and rheumatoid arthritis. There can also be a link with obesity and type 2 diabetes.

Supporting the vagus nerve

As we age, our vagal response declines. However, there are ways in which we can improve the functioning of our vagal nerve and receive powerful benefits to our health and wellbeing.

• Yoga and meditation improve the stress response, building resilience and reducing anxiety due to the relaxing and anti-inflammatory effect of the vagus nerve
• Slow, deep belly breathing triggers the vagus nerve to slow heart rate and reduce blood pressure
• Eating a fibre rich diet increases a hormone that supports communication between the vagus nerve and the brain, slowing down stomach emptying and gut movements and keeping us feeling fuller for longer
• Singing, chanting, gargling and activating the gag reflex engage the vocal-chords which then stimulates the vagus nerve
• Cold water immersion: the current craze for cold water swimming is not just a fad. It has been scientifically shown to support mental wellbeing, stimulate the gut, decrease heart rate and boost the immune system, in part by activating the vagus nerve. Take a dip in your local outdoor pool or the sea on a regular basis. If that’s too much then just turn the water to cold for at least 30 seconds at the end of your shower. Or, immerse your forehead eyes and at least 2/3 of both cheeks into cold water
• Reflexology foot massage can assist in stimulation of the vagus nerve to lower heart rate and blood pressure
• Lastly, laughter may really be the best medicine! It stimulates diaphragmatic breathing and vagus nerve response in the parasympathetic nervous system triggering relaxing health benefit