Breathe: the New Science of a Lost Art by James Nestor

NB: This is not health advice.

This book was something I picked up out of interest while browsing and a particularly easy read. Having already experimented with the Wim Hof Method of breathing and cold exposure this book added significant context around the history of breathing techniques and folk wisdom around the importance of how we breathe.

The author goes on a personal journey and in doing so instructs on a number of key findings from the collective wisdom and science on how the way you breathe can affect your health. I am particularly interested in seemingly basic things like just resting well when sleeping, which is something that eludes many, especially those suffering from conditions like obstructive sleep apnoea, or even just plain snoring.

A very brief summary, but the key points I took away from this book were:

• We should always breathe in and out through our nose, wherever possible
  • Breathing in through the nose causes the internal release of nitric oxide which improves oxygen absorption, amongst other posited benefits. Breathing through the mouth does not have this effect ¹.
• When reaching your physical limit in exercise, sometimes the issue is a lack of carbon dioxide, not oxygen, and breathing through our nose, slowly, will result in higher carbon dioxide concentrations.
  • The key here is that carbon dioxide is needed to release oxygen from the haemoglobin/bloodstream to where it is needed, so having too little carbon dioxide in your body/muscles could cause you to be fatigued even if your oxygen levels are sufficiently high.
• In a healthy person it is trivial to keep the oxygen level of the blood high enough–this is something I’ve observed myself using a pulse oximeter.
• Chewing and working the jaw is vitally important, from early childhood through to late adulthood. If the food isn’t tough enough then chewing gum is recommended.
  • While I’m not sure I would give children gum, it makes sense to me that eating lots of relatively soft (and likely processed) food could lead to an under-development of the jaw and airways.
• Chewing seems to be related to stem cells, and the seams between parts of the skull (!). One of the more curious physiological claims in the book, that I would like to look at the sources for.
• There are such interesting and curious books from the distant past such as George Catlin’s ‘Shut your mouth and save your life’, published in 1870.

The book ends with brief descriptions of a number of breathing exercises, with just enough detail so that you can try them out if you like.

I have also been interested in this particular topic in relation to the pandemic, as an inability to breathe was one of the main problems. A surprise learning here was that the illness would damage your lungs' ability to absorb oxygen, while preserving their ability to expel carbon dioxide. Feeling out of breath is a sensation caused by having too high a concentration of carbon dioxide (the body does not know how much oxygen it has), which has lead to people with critically low blood oxygen levels even though they feel fine. It is because of this that I recommended to many to keep a pulse oximeter handy if they were ill, as without one you can’t easily tell whether you’re in trouble or not, and missing this signal could be critical.