(Hat tip to @rbhinkley for pointing out the original article)
Imagine a world where CO2 was not a deadly poison in need of urgent regulation by the European Union and the Environmental Protection Agency but a hugely beneficial trace gas which helped plants to thrive… If you’ve read [Delingpole's tastefully plugged book] Watermelons – or indeed hung around this column for any length of time – you’ll know that that world already exists.
So begins James Delingpole’s latest blog post. Let’s start with the slightly less obvious problem here: governments do not control carbon dioxide because it is a poison, they control it because it has damaging effects on the environment. Whether or not it’s poisonous has no bearing on climate change.
Secondly, carbon dioxide is poisonous. It’s not poisonous at the levels you’ll find in the air around you, assuming you’re reading this from a reasonably well-ventilated room, but at a concentration of around 3% you’ll start to feel drowsy, and as the concentration increases you’ll quickly suffer sensory impairment and eventually black out and can even die. Your body does need a tiny bit of carbon dioxide in the blood, otherwise you suffer what’s known as hypocapnia, but that’s not caused by environmental CO2, that’s caused by hyperventilating (it’s a big problem with divers, which is why you shouldn’t take short, hard breaths before diving).
So why does Delingpole want to claim otherwise? Well, he’s discovered something called the Buteyko Method – supposedly a way of breathing which increases the amount of carbon dioxide in your body, supposedly curing collapsed lungs, ME, MS, depression, arthritis, asthma, emphysema and even Crohn’s disease.
The only evidence Delingpole gives that it works? Well, it works for him. Fair enough – controlled breathing techniques are widelyknown to reduce stress, and if that helps him personally then fine. But remember he’s a journalist – surely before he sells it to his readers (and it does read like a sales pitch – he lists the locations of upcoming workshops… £375 workshops) he should find some concrete evidence that it works – and, crucially, that it has anything to do with CO2?
There’s not much research into whether it works, unfortunately, and a lot of it doesn’t seem to be fantastic quality. Still, here’s a quote from a review paper looking into the method (in particular, its effect on asthma):
Buteyko’s theory relating to carbon dioxide levels and airway calibre is an attractive one, and has some basis in evidence from experimental studies. However, it is not known whether altering breathing patterns can raise carbon dioxide levels significantly, and there is currently insufficient evidence to confirm that this is the mechanism behind any effect that [Buteyko Breathing Technique] BBT may exert. Further research is necessary to establish unequivocally whether BBT is effective, and if so, how it may work. (emphasis mine)
Doesn’t sound fantastic. Maybe the paper “Strengths, Weaknesses, and Possibilities of the Buteyko Breathing Method” will be more promising.
Studies with the Buteyko Method have found that resting carbon dioxide levels do not change after Buteyko training despite reported improvement in symptoms
Ok, how about a study from the same author, “Investigating the Claims of Konstantin Buteyko, M.D., Ph.D.“
The results revealed a negative correlation between BHT and ETCO2 (r = −0.241, p < 0.05), directly opposite to Buteyko’s claims.
[ETCO2 is end tidal CO2, the amount of CO2 released at the end of a breathing cycle]
Or how about this large, randomised controlled study* – again into its effects on asthma.
This study, which we believe to be the largest randomised controlled trial and the first to use a global assessment of asthma control as a primary outcome in a non-pharmacological intervention in asthma, failed to show a difference between the intervention (Buteyko) and control (physiotherapy) groups.
Even Wikipedia, refuge of the lazy journalist, points out that there is no evidence that the CO2 theory is correct and there’s little medical support for the technique!
Where does that leave us? There’s not much evidence that it works, no evidence that it increases CO2 levels, and indeed, some evidence that it may have the exact opposite effect. Does it help with asthma? Perhaps, although apparently no better than any other breathing method. Does it prove that CO2 is unequivocally good for you? Of course not.
* Although as the researchers point out, it was not blinded – which makes the fact that it didn’t work even more striking.