So what does the science say?
Indeed vagus nerve stimulation is a thing. It has several decades of (somewhat successful) use in epilepsy to reduce seizure frequency.
Also in 2005 the USA FDA approved vagus nerve stimulation for long-term treatment-resistant depression (Daban, Martinez-Aran et al. 2008). It is also breaking ground for use in reducing arthritis symptoms (Koopman, Chavan et al. 2016).
The downside – vagus nerve stimulation involves a minor surgical procedure, somewhat comparable to getting a pacemaker put in. A wristwatch-sized device is implanted in the chest wall. Clearly given surgery is needed (even if ‘minor’) it is not without its downsides and risks.
The good news is, some headway seems to be being made with a device that stimulates the vagus nerve without surgery via the ear (Frangos, Ellrich et al. 2015).
If you google “vagus nerve stimulation” you will see information from chronic illness bodies and association discussing these procedures. If you google-scholar the same phrase, you will find some of the references below.
Change your search ever so slightly (oh the joys of Google*) to “How to stimulate your vagus nerve” and you get a host of anecdotal and folklore information about exercises you can do at home. Here are some of the delights you might find:
- Splash water on your face
- Hold your breath
- Try to poop without pooping (called a Valsalva Maneuver)
- Hold your nose and blow like you are landing in an aeroplane (ditto).
You are also likely to read all manner of claims about what this things might achieve for you in terms of your overall health and wellbeing, or curing major chronic illnesses, even cancer.
So what does the science say about these stimulation ideas?
Not a lot.
I did find that maybe there is something in splashing really cold water on yourself. A study by Mäkinen, Mäntysaari et al. (2008) indicates that such cold dunking might move you towards parasympathetic dominance. Remember that is the side of the autonomic nervous system that the vagus nerve is a major part of. I don’t see any indication as to whether this short-term shift is going to have any long-term benefits. Maybe have a bucket of ice water on hand for your next terrifying public speaking engagement it just might calm you down while entertaining your audience.
Maybe too there is something in fasting (Mager, Wan et al. 2006) however that probably fits more in the lifestyle section of part 2.
There is also research to support the use of the Valsalva movement to stop a racing heart (Lim, Anantharaman et al. 1998). I have first-hand experience here as I have a type of congenital heart arrhythmia and have used the Valsalva to stop it. I have also taught myself the best and latest technigues and asked the researchers personally for more details, there wasn’t much. It is important to note this is a narrow and specific use of the technique, one should always extrapolate with caution.
When thinking of very specific findings – there appears to be a potential link between the kind of Valsalva one is forced into when pooping on western toilets and heart attacks (Sikirov 1990). Do go carefully, friends.
What’s the heads up?
As to whether these ‘exercises’ you can do at home have longer-term health benefits (even if they might temporarily stimulate your vagus nerve). I’d suggest starting with the tried and trued not rocked science approaches discussed in Part Two. Or ask your grandmother for general health tips, she is likely to say the same things.
Or perhaps you want to do some experimenting on your own vagus nerve. Great news – Part 4 will show you how.
Meanwhile go thoughtfully in the direction of your dreams.
Yours as ever,
Links, References and all that Jazz
*Do remember your google searches are highly personalised. Uncle Google knows what you have been doing (true story) and incorporates this into what he thinks you might be more interested in. So if you get the latest celebrity pooping stories – do not blame me.
Here are the parts of this series:
- Part One: The Wanderer – A Brief Introduction to the Vagus Nerve (our Hero).
- Part Two: How to improve the health of your Vagus Nerve – based on scientific evidence.
- Part Three: Vagus nerve stimulation; can you really ‘gag’ your way to good health?
- Part Four: Do try this at home; monitoring your own vagus nerve health using the variability in your heart rate.
Daban, C., et al. (2008). “Safety and efficacy of Vagus Nerve Stimulation in treatment-resistant depression. A systematic review.” Journal of Affective Disorders 110(1): 1-15.
Frangos, E., et al. (2015). “Non-invasive access to the vagus nerve central projections via electrical stimulation of the external ear: fMRI evidence in humans.” Brain Stimulation 8(3): 624-636.
Koopman, F. A., et al. (2016). “Vagus nerve stimulation inhibits cytokine production and attenuates disease severity in rheumatoid arthritis.” Proceedings of the National Academy of Sciences 113(29): 8284-8289.
Lim, S., et al. (1998). “Comparison of treatment of supraventricular tachycardia by Valsalva maneuver and carotid sinus massage.” Annals of emergency medicine 31(1): 30-35.
Looga, R. (2005). “The Valsalva manoeuvre—cardiovascular effects and performance technique: a critical review.” Respiratory physiology & neurobiology 147(1): 39-49.
Mager, D. E., et al. (2006). “Caloric restriction and intermittent fasting alter spectral measures of heart rate and blood pressure variability in rats.” The FASEB Journal 20(6): 631-637.
Mäkinen, T. M., et al. (2008). “Autonomic nervous function during whole-body cold exposure before and after cold acclimation.” Aviation, space, and environmental medicine 79(9): 875-882.
Sikirov, B. (1990). “Cardio-vascular events at defecation: are they unavoidable?” Medical Hypotheses 32(3): 231-233.
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