Part 3 of 4: Vagus nerve stimulation; can you really ‘gag’ your way to good health?
Welcome to part 3 of a 4 part blog on the vagus nerve.
Here are the parts:
- 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.
As a card carrying member of multiple chronic illness forums, I get to notice across forum trends. A trend I notice in the last few months is anything to do with the vagus nerve and in particular ‘vagus nerve stimulation’.
We talked of general lifestyle ways to improve the functioning of your vagus nerve (yoga, meditation etc.) in Part two; today we focus on the specific idea of vagus nerve stimulation.
So what does the science say?
Well indeed vagus nerve stimulation (VNS) is a real thing. It has several decades of (somewhat successful) use in epilepsy to reduce seizure frequency. In 2005 the USA FDA approved it for long term treatment resistant depression (Daban, Martinez-Aran et al. 2008). It is also breaking ground in arthritis and more (Koopman, Chavan et al. 2016).
The downside is VNS involves a minor surgical procedure, somewhat comparable to getting a pacemaker put in. A wrist watch 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 head way 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 it you will find some of the references below.
Can you try this at home?
Change your search ever so slightly (oh the joys of google) to “How to stimulate your vagus nerve” and you get more anecdotal, folk lore type information about exercises you can do at home. Splash water on your face, gag, hold your breath, try to poop without pooping, hold your nose and blow like you are landing an aeroplane. These last two are called Valsalva Maneuvers.
NOTE: Do remember your google searches are highly personalised. Uncle Google knows what you have been doing (yes 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.
So what does the science say about these stimulation ideas?
Well it would seem not a lot. Do please share any research you have found as I have not done a systematic review, which would take several moons. As much as I would love to do that, I am not certain I could find an academic journal willing to publish it.
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 too there is something in fasting (Mager, Wan et al. 2006) however that probably fits more in the lifestyle section of part 2.
But wait there is more
This blog was not far off going to press when my body decided it would do some field research for you. I am retreating on my family farm in northern New Zealand, to write, relax and heal … nice …. accept on day one I was pottering around relaxed and happy …..
…. when bam my resting heart rate jumped to maybe 200 beats per minute (you could not count it and neither could my fitbit) …..long story short I end up in A and E (after an hour drive through the country). The Nurse asked if I had tried the Valsalva maneuverer to stop the tachycardia (racing heart).
And sure enough I see there is something in the potential for the Valsalva to stop a racing heart, albeit in only about a quarter of cases. Lim, Anantharaman et al. (1998) looked at using the valsalva to stop a type of racing heart that comes from the bottom chambers (racing hearts are an entire complexity all to themselves, one I am not pleased to be learning more about over the coming weeks).
So just for fun over the last few days if I have caught my heart rate at over 100, I have tried the valsalva. Several times it did drop quite suddenly, once it raised. I also tried it with all my heart ‘kit’ on and it also lifted my HRV, however it was brief and dropped back with 30 seconds to a minute.
I have also discovered that certain things about your cardiovascular health might be able to be obtained from your response to the Valsalva and also that exactly how it is done matters too (Looga 2005). I am stopping here however before I open a can of worms for us both and get too off track.
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 am just not confident for a strong opinion either way.
There are certainly some people with pretty impressive backgrounds who support these ideas. Like this one (which uses extended breath holding):
I need a wee disclaimer here: try them at your own risk as I have not found anything to confirm their safety, or indeed their harm (accept perhaps in maternal and fetal distress).
UPDATE!! Be warned, there appears to be a link between the kind of valsalva one is forced into when pooping on western toilets and heart attacks (Sikirov 1990).
As for me, I will still first prioritise the lifestyle things covered in Part 2. In spare time I may have some fun with these new ideas, which I will monitor my progress on. In the next blog I will show you how to monitor your vagus nerve happiness via your HRV (heart rate variability).
It is really rather fun if you are jumping on the quantifier movement … if not … leave the fourth installment well alone and return to the lifestyle things already discussed. You can be safe in the knowledge you are doing your mind and body good regardless of whether you can track it daily with a number.
Meanwhile go thoughtfully in the direction of your dreams.
Yours as ever,
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.