12
$\begingroup$

My question is: Does voluntarily holding your breath at atmospheric pressure for a few minutes can cause brain damage? I'm talking about periods of time around 3 minutes.

I've read there are some studies showing brain damage in deep-water divers. However, it seems to me as insufficient evidence for breath-holding in general: it could be that frequent changes in pressure are the cause for damage, for example. Or the fact that the person cannot resurface immediately after feeling the need to breathe, which might cause them to hold their breath for a longer period of time than their body allows.

So are there any studies showing results for the effect on the brain in (healthy) humans holding their breath?

|improve this question
$\endgroup$
  • $\begingroup$ It's going to be very variable, some people struggle for 30 seconds, some manage (e.g. freedivers) 10 minutes at a time. Do you have links for these studies? $\endgroup$ – rg255 May 15 '15 at 9:38
  • 1
    $\begingroup$ there is health.SE if you were searching for more medicine-related stuff. However, i think your question will do fine here. +1 $\endgroup$ – AliceD♦ May 15 '15 at 9:50
  • 2
    $\begingroup$ @rg255 For example this: the-aps.org/mm/hp/Audiences/Public-Press/Archive/09/32.html (I'm not a neuroscientist so I don't know how credible this source is, though). I know people can manage to hold their breath (I used to do it for 3 minutes at a time), I'm wondering whether damage can be made even if the person doesn't feel great discomfort. $\endgroup$ – Pandora May 15 '15 at 10:02
  • 4
    $\begingroup$ I'm pretty sure that your brain will force you to take a breath before it takes damage. This is also the reason why you can't commit suicide by holding your breath (en.wikipedia.org/wiki/Breathing#Interaction). $\endgroup$ – Hav0k May 15 '15 at 13:00
  • $\begingroup$ Look at this very related question: biology.stackexchange.com/questions/31554/… $\endgroup$ – cagliari2005 May 21 '15 at 2:01
1
$\begingroup$

In order to reply to your question I (*) need to dissect it into 3 parts.

1 - Can you voluntarily hold your breath so long that damage actually occurs? There is evidence that apnoe-divers damage their brains while diving. In the above, the marker protein S100B, representing brain, damage was elevated. This marker had been found previously to be increased in stroke and other forms of brain damage. Therefore, it appears that brain damage occurs when trained freedivers hold their breath on average 335 s (range 281-403 s). I could not find published data on whether this results in cognitive changes. Another really interesting study I found was also on US Navy divers but with oxygen supply. Their cognition was tested and transient alterations in affect, visual focusing, and physical activity were temporarily seen for 10 days after diving. Pressure changes might have an impact on top of the lack of oxygen.

2 - To summarize a study from a good previous post, researchers measured oxygen saturation in the blood while subject were holding their breath. Oxygen saturation dropped as low as 75% (see original paper).

3 - Additional studies. A blood oxygen level dependent functional-MRI study in adults and children showed similar activated regions while holding their breath. Breath holding in childrens’ brains causes stronger alterations. Their brains seem to be more vulnerable than adult brains. The insular cortex was identified as a specific region in the brain, being responsible for breathing again after holding breath. These findings originate from a positron-emission study which was able to localize air hunger to the insular cortex. The insula is part of the limbic system which regulates essential tasks in humans including temperature, nausea, and pain. Feeling shortness of breath is important for survival and therefore as shown with PET also located in the limbic system.

(*Note that I'm submitting this well researched answer for Tim, an MD, who took the time to write the text but doesn't have the time to sign up or reach the required reputation limit to post. I only filtered out some medical lingo and streamlined the text. The kudos are his.)

|improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.