The premise is dramatic: you can live days without food or water, but only a few minutes without breathing. Against this background, how can it be that you do not pay adequate attention to such a necessary gesture? There are a thousand and one sources that address this question: fitness blogs, self-help books, martial arts guidelines, instructor recommendations … In such an overwhelming context, no one would question the importance of controlling your breath. Or if? Does the evidence support such relevance or is it just another fad? Today we review what we know about one of the most repeated “mantras” in the healthy universe: learning to breathe.
What are the purported benefits of nose breathing?
In the healthy boom, common and necessary actions such as breathing have not gone unnoticed in this compendium of tips and tricks to “live better.” In fact, starting with what we know, respiration has been the subject of scientific study since the eighteenth century, or maybe before, just as how do they collect from the Laboratory of Experimental, Theoretical and Applied Respiratory Physiology of the Faculty of Medicine of Grenoble. There are certain patterns that, far from being random, can be related to a person’s health. Does that mean that we can change our breathing to improve our health?
Although the previous study did not talk about the orifices through which the air enters and leaves, repeated in all the speeches is the need to breathe through the nose, and not through the mouth. As far as we know, in the world of medicine asserts itself that breathing through the nose allows the air to warm up before reaching the lungs, makes it moistened and helps filter out particles. It also helps to smell, of course, and, well done, they claim, helps breathing with the diaphragm and correct placement of the tongue.
In addition, fitness professionals advocate that breathing through your nose helps sports performance, and even some researchers, among the most famous Konstantin Buteyko. This Ukrainian doctor thought that many diseases are caused by chronic hyperventilation.
To solve it, he proposed the use of respiratory reeducation techniques. Currently, the Buteyko method continues to be used in certain circles, especially against asthma, where there are some studies They claim a positive result. Therefore, properly controlling breathing, and not only breathing through the nose, but also its rhythm and flow, according to its proponents, can help improve rest at night, reduce the consequences of asthma, and even improve sports performance. But we don’t stop there. There is another series of affirmations that proclaim to the four winds the benefits of breathing through the nose.
The case of NO when breathing through the nose
For many proponents of nose breath control, nitrous monoxide, or NO, is a prime example of the benefits of its techniques. And, we have known for a long time that this gas occurs in the nasal cavity. We have also known for years that a small proportion is absorbed. The most interesting thing is that this molecule has been shown to have beneficial effects, yes.
For instance, NO has a vasodilator effect with the ability to relax the muscular layers of the endothelium, acts as a neurotransmitter in the brain and is produced by numerous cells with very diverse physiological functions. In this way, the benefits have been related by medical professionals, over the years, with various therapies and pseudotherapies that take advantage of this knowledge and sometimes attribute quasi-magical properties to NO (it has even been postulated as protector against COVID-19).
However, as was the case with everything we have already mentioned, we are facing a case of correlation without evidence: there is no scientific consensus to show that NO produced by the nose has a significant beneficial relationship with our body. In any case, it is very little and the rest of the body produces it when it needs it. What’s more, they exist various meta-analyzes that have been shown to inhale external NO does not produce any kind of benefit significant.
Breathing through your mouth deforms your jaw … if you are a monkey or a child
There are several studies that have shown that breathing through the mouth during the development stage can lead to a deformation of the tissues. This has been proven in monos Rhesus and has hypothesized in children. The mechanisms are complex and difficult to understand. Some are related to the respiratory effort itself, with the air flow or with the oxidative factor. In any case, there is the possibility of a facial deformation associated with breathing through the mouth during the first months of life.
Does it happen with adults? No. In fact, the tissues are already developed and will not be deformed by breathing through the mouth. In general, the few studies that talk about the consequences of mouth breathing, whether positive or negative, are with a small sample, anecdotal or inconclusive. The same is the case with breathing through the nose, in normal cases, where there is no reason to fear a deformation of the jaw.
Finally something good: breathing through your nose stimulates your brain
Yes, there is a positive reason to breathe through the nose instead of the mouth, helps our brain. Specifically, to memory. Interestingly, there is evidence that breathing through the nose, and its association with odors, offers neurophysiological and neurological benefits. Specifically, it helps to properly stimulate neurons in the hippocampus and the prefrontal cortex, such as as they demonstrated these researchers from the Department of Anatomy and Neurobiology at the University of Tennessee Health Sciences Center.
In this other study by the University of Korea, the hypothesis of a possible mechanism in this regard, related to the oxygen saturation as a switch for various cognitive functions. Besides oxygen, odors are powerful triggers of brain activity. It is one of the most developed senses in primates and is directly related to learning processes, so its relationship with neural plasticity seems logical and agrees with the studies that support it.
Between the lack of evidence and the correlation
As we have seen in the previous cases, in reality, and despite the fact that many people, including science journalists, researchers from various areas or fitness professionals are forcefully reaffirmed about the benefits, the truth is that there are few or no results that close a consensus about how good it is to breathe through the nose. Those that exist, on the other hand, are not directly related to these statements.
For example, while there are some studies that offer positive results when treating asthma with the Buteyko method that we talked about at the beginning, for example, these do not pass the more rigorous studies O meta-analysis, which calls into question the claims of this doctor and their validity. Why has there been an improvement in asthma in patients treated with this method, then? It can be for many things: by psychological factors, confirmation biases or by physiological mechanisms that we do not know.
In other words, there could be a correlation to this breathing thing, but there is no causation. Other studies, like this carried out by BCN MedTech researchers, serve to affirm that we do not breathe well. Nevertheless, there is no reason to think that this may have a negative consequence. It is a muscular and volumetric, postural study, but not of the health consequences that this may have. Even so, there are those who assume and use these studies to reaffirm their hypothesis without solid evidence.
In fitness, the question is even more difficult. First, many of the claims are based on unwarranted premises mixed with partially valid values and hypotheses. For example, we know that there is an effect on the sports performance based on the respiratory pattern, concentration and tolerance to CO2, etc. Nevertheless, this occurs in situations of sports stress. Does it make sense to consider the same values in a normal situation? At the moment there is no data to support it. Therefore, for a normal person, in a normal situation, there is no scientific evidence that conclusively affirms that breathing through the nose and controlling breathing have the benefits attributed to them.
Bottom line: nose breathing is good, but not a panacea
Some things are clear: breathing through the nose and working on breathing control can help us to improve the rhythm of breathing during exercise, filter the particles and moisten the air that enters and stimulate some neurological mechanisms. And the rest of the benefits? Well, they could be there or not. Leaving aside all those who have not passed the test of science, of course.
In short, learn to breathe it might have some good things, but nowhere near the ones that are almost magically attributed to this technique. To be able to do this, first, there should be enough experimentation, which is not because of how complicated it is. Second, the evidence must be more than anecdotal and cannot be limited to reasoning and correlations, but must be supported by facts.
On the other hand, learning to breathe through the nose and at a rhythm does not, in principle, no harm and yes some benefits. In this case, we only have to ask ourselves “why not try it?”. At the end of the day, the only thing we could get out of this practice is something good, and in the worst case, we will stay as we were.