Carotid sinus

• In fact, we have two vagus nerves – a left and a right – and their optimal functioning is essential for good physical and mental health.
• Many social media posts describe ways to reset the vagus nerves to reduce stress and increase calm.
• But the vagus nerves also play a part in why socialising, sex and sports are good for our health and wellbeing.

Our rest-and-digest-and-restore system

• The vagus nerves are part of the parasympathetic nervous system, which does the opposite: rest, digest and restore.
• The sympathetic nervous system increases heart and breathing rates, slows down digestion and lowers the immune response.
• The parasympathetic nervous system via the vagus nerves is the counterbalance to our stress response.

The wandering nerve

• Vagus means wandering in Latin and is where the words vagrant, vagabond and vague come from.
• These are the tenth cranial nerves, the longest of the 12 pairs of cranial nerves that connect the brainstem and the body.
• However, about 80% of vagus nerve fibres carry information from organs back to our brain.

Can you measure the health of vagus nerves?

• Instead, heart-rate variability is used as a surrogate measure of vagus nerve activity.
• This is the slight beat-to-beat differences in heart rate that occur naturally, related to breathing.
• Many wearable devices measure heart rate and heart-rate variability and can be a useful way to monitor vagal tone.

So is there any science to back the vagal nerve hacks online?

• Cold-water immersion on the face or neck stimulates the vagus nerves via a reflex of the skin’s nerves.
• Singing and humming can increase our vagal tone because the vagus nerve innervates our larynx (voicebox).
• There are also claims simple eye movements can reset the vagus nerve.
• Carotid sinus massage can also be used clinically to increase vagus nerve activation and lower a high heart rate.

Social connection and feeling safe

Polyvagal theory suggests positive social communication and feeling safe increases vagus nerve activity. This promotes healthy growth and restoration activities in our body and increases positive emotions. The vagus nerves have a role in social communication because they are linked with our facial expressions and voice. Smiling and being smiled at can stimulate our vagus nerves.

Sport, sex and slowing down

• Slowing down with others, such as lying down next to a friend on a picnic blanket and looking at the clouds, also stimulates the vagus nerves.
• Whether it’s through mindfulness, paced breathing, sports, sex or simply smiling, increased vagal tone is important for good health and wellbeing.
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