Part 2 of 4: How to Improve the health of your Vagus Nerve (using science)
Welcome to part 2 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.
First a reminder that Heart Rate Variability (HRV) is our best measure of ‘vagal tone’ or the health of your vagus nerve (and wider Autonomic Nervous System) – see part one for more details.
Today we are interested in how to improve the health of your vagus nerve; our focus is on techniques that have at least some scientific support (even if it is in its infancy).
Let’s start with the bleedin obvious. Exercise is good for your HRV and drinking truckloads, smoking and taking drugs is very bad. Stress is also bad. So all the fun stuff is out, what is left for us?
There is increasing interest over recent decades by scientist in mindfulness meditation. Who isn’t mindfulness getting fashionable with – right?
However different types of meditation might have different effects, which begs the question … which techniques are likely to be best for your HRV? One of our few HRV gurus, James Heathers, and some colleagues had a good look at Vipassana meditation (Krygier et al., 2013) and it looks …well on closer examiunation ….. unclear, although some things within HRV changed (very technical stuff), overal HRV did not seem to improve. Vipassana is taught in a standardised manner world-wide in a 10-day course (with about 100 hours of practice – my word). If you want to dip your toe in without that sort of terrifying commitment here is a lovely video:
Loving Kindness Meditation is also being studied at the UCLA Mindfulness Awareness Research Centre and has also been linked to HRV (although as mentioned in other blogs the study linking the two had major methods flaws).
UCLA offer free downloads that are really nice (not quite chardonnay but worth a crack):
Update in my thinking from my work on it for my PhD (where I used mindfulness to try and imrpove HRV): Maybe mindfulness/mediation does not improve HRV after all ( I know, horrible right?). However I’m not ready myself to throw it out. Also it does show other clear cognitive benefits. So for now I’m keeping it on my list, with disclaimers.
Singing has been linked to heart rate variability (Vickhoff et al., 2013). I don’t even think you need to be good at it. However I have a feeling that singing has benefit mostly because it slows your breathing rate down. Looks like Vichoff et al might agree with me. You see … it turns out more mantra type, repetitive or rhythmic singing works better. The idea that it might be all about the breath … brings us nicely to a pet topic of mine – paced breathing.
How often have you been told to “just take a deep breath”. Before you rush off and do so, it really may not be that simple.
Perhaps what you should be taking is a nice, slow gentle, paced breath. Breathing in for around 5 seconds and out for around 5 seconds. Well actually even better 5.5 seconds each way. Even better still is to find your personal ‘resonant breath’ … and breathe at that. It is likely to be somewhere around this 4-6 breaths per minute. It depends on a number of things, a key one being the size of your lungs.
Without knowing your resonant frequency (and who does?), I would go for 5.5 seconds in and 5.5 seconds out, without holding on the in or out. Why? …..well a neat study by Lin, Tai, and Fan (2014) actually compared a range of different breathing patterns, including holding on the in or out and how they influenced HRV. The winner? 5.5 seconds in and 5.5 seconds out, no holding. I realise one study is only one study, but when little is there … it is a sensible place to start. Another update: I have since been playing with 3 seconds in and 6 seconds out (from some other information I fell across, I think it is working, but I can’t be sure).
I have a theory that some of the ‘deep breathing’ that is fashionable may in fact lower your HRV (this is not the direction you want it to go – more is better with HRV). My concern is around the panting type breathing that leaves you light headed a little like hyperventilating, which is kinda what it is. However this is just a suspicion, one I would dearly love the funding to research at some point. For now … go cautiously and trust your own responses to different breathing techniques.
In order to support gentle, paced breathing there are some great free products on the market. Simply search for “paced breathing” or “breath pacer” in your app store. The one I used for research was on android and called “paced breathing”, it’s logo is shown here below. I found it reliable, and it allows you to enter half seconds which some don’t. It also has a sound option, so you can close your eyes. There are many others. I would love to hear in the comments how you are going with them, what ones you have tried, and if you are finding through trial and error your own “resonant breathing pattern”.
By the way I am would not be surprised if some people are more comfortable with a short holding of the breath on the in and/or out ….. there is not enough research in the one small study above to exclude this possibility ….. let me know how you go.
PLEASE NOTE: I do not know what is safe with children. So please avoid this with children or consult a professional.
Now here is something pretty cool. The idea that you can use direct feedback on your heart rate variability to improve it. There does seem to be some research to support this e.g Auditya Purwandini, Muhammad Nubli Abdul, and Nora Mat (2010). I actually considered using this approach in my research. The logistics stopped me. Also it is pretty complex and involves monitoring of your heart rate variability and respiration. So how should you try biofeedback? If you want the gold plated version, there are increasingly trained practitioners around the world. You can find a practitioner here (however there are not many specific HRV certified ones).
For a ‘try this at home’ version the original player in the market is the Heart Math Institute. They have a range of fun interactive visuals games, such as attempting to fly a hot air balloon across lovely landscapes … the balloon rising with your improvements in HRV. I have enjoyed these products but am not prepared to state how accurate they are. I suspect there is benefit in them and they have published research. However in later blogs we will talk about conflicts in research, where research is funded by an organisation selling the products, you should always ask questions and go cautiously.
I see apps are also coming into this market. I may check out the latest and review them in the future, for now the techies are moving pretty fast. I worry a little that the commercial products are moving faster than the science. Also reviewing these products is pretty challenging, and for some it is impossible to ‘get in the back’ and see if their data is accurate. This is not a reason not to give them a go … try what works for you … see what happens. In future blogs I’m going to teach you how to measure your own Heart Rate Variability as accurately as possible … so you can indirectly assess these tools and apps by seeing if your HRV does indeed improve through regular use.
In an interesting (albeit small) Japanese study, 12 students were assigned to either forest bath, or watch an urban streetscape for 3 days. The forest bathers had better HRV as well as other physiological measures (Han et al., 2016). I realise this is a super small sample size, however those who were “habituated to smoking and drinking” had to be excluded making sense of the small sample size with students – perhaps.
You are probably not surprised by now to realise yoga has been linked to improved HRV (Sarang & Telles, 2006; Satyapriya, Nagendra, Nagarathna, & Padmalatha, 2009)
I have wondered a lot about diet and not studied it in depth as I have been more focused in my research on the interventions discussed above. A very quick look shows me there is not a huge amount in this area however I discovered fish (with a focus on tuna) is linked to HRV (Mozaffarian, Stein, Prineas, & Siscovick, 2008). I suspect diet is likely to fit into the bleedin obvious stuff. Poor HRV is a risk factor in heart diseases and we are all aware of the general heart disease goodies and badies (even if some of them have changed over the years – eggs anyone?)
So there we have it ….. some great places to start working with your vagus nerve.
There has been a lot of interest in certain techniques, blowing, gagging, pushing (like you are a going to poop) etc … these will be covered in part 3 of this series. In Part 4 you will learn how to measure your own vagal tone at home.
Thanks for dropping by,
Go well in the direction of your dreams.
Yours as ever
Auditya Purwandini, S., Muhammad Nubli Abdul, W., & Nora Mat, Z. (2010). Heart Rate Variability (HRV) biofeedback: A new training approach for operator’s performance enhancement. Journal of Industrial Engineering and Management, 3(1), 176.
Han, J.-W., Choi, H., Jeon, Y.-H., Yoon, C.-H., Woo, J.-M., & Kim, W. (2016). The Effects of Forest Therapy on Coping with Chronic Widespread Pain: Physiological and Psychological Differences between Participants in a Forest Therapy Program and a Control Group. International journal of environmental research and public health, 13(3), 255.
Krygier, J. R., Heathers, J. A., Shahrestani, S., Abbott, M., Gross, J. J., & Kemp, A. H. (2013). Mindfulness meditation, well-being, and heart rate variability: a preliminary investigation into the impact of intensive Vipassana meditation. International Journal of Psychophysiology, 89(3), 305-313.
Lin, I., Tai, L., & Fan, S. (2014). Breathing at a rate of 5.5 breaths per minute with equal inhalation-to-exhalation ratio increases heart rate variability. International Journal of Psychophysiology, 91(3), 206-211.
Mozaffarian, D., Stein, P. K., Prineas, R. J., & Siscovick, D. S. (2008). Dietary fish and ω-3 fatty acid consumption and heart rate variability in US adults. Circulation, 117(9), 1130-1137.
Sarang, P., & Telles, S. (2006). Effects of Two Yoga Based Relaxation Techniques on Heart Rate Variability (HRV). International Journal of Stress Management, 13(4), 460-475. doi: 10.1037/1072-5245.13.4.460
Satyapriya, M., Nagendra, H. R., Nagarathna, R., & Padmalatha, V. (2009). Effect of integrated yoga on stress and heart rate variability in pregnant women. International Journal of Gynecology & Obstetrics, 104(3), 218-222.
Vickhoff, B., Malmgren, H., Aström, R., Nyberg, G., Ekström, S.-R., Engwall, M., . . . Jörnsten, R. (2013). Music structure determines heart rate variability of singers. Frontiers in psychology, 4, 334. doi: 10.3389/fpsyg.2013.00334