Becoming Attractive and Fearless... with Your Nose

PMID is the pub med identification number which you can simply copy and put in any search engine to find an article on pubmed. I will use this if there is no DOI.

Nasal breathing… Breathing through your nose right? Ya.

It may come as no surprise to you, but the nose is meant for breathing. What may surprise you is that to avoid breathing through your nose, and instead, to breath through your mouth is detrimental to your health and quality of life. Its still all just oxygen right? Well… not quite.

Lets get all of the benefits of nose breathing out of the way first and then I will explain why not quite:

1. Daytime alertness levels tremendously,

2. It greatly increases quality of life

3. It forms your face to be healthier and therefore more attractive

4. It eases exercise-induces asthma symptoms, and regular asthma attacks

5. It forms and can increase the sense of smell

6. It can increase time-to-exhaustion during exercise

7. It increases cognitive (thinking) function

8. It makes breathing more efficient

9. It helps to better prevent infections and fight respiratory infections

10. It betters heart rate variability

11. It helps with halitosis (bad breath)

12. It helps prevent tooth decay

13. It helps prevent aspiration (swallowing of air)

(https://doi.org/10.1097/01.mlg.0000239111.24094.a3, 10.2500/ajr.2007.21.3087, 10.1007/s11882-008-0025-7, PMID: 8599744, 10.3389/fphys.2022.813243, 10.1016/j.micinf.2020.05.002, 10.1538/expanim1957.26.2_149)

There you have it, thirteen incredible reasons to breath through your nose… lets get into the fun details of it. Why are all these the effects of nose breathing and why do the same effects not happen when you breath through your mouth?

1. Daytime alertness levels tremendously

2. It greatly increases quality of life

Nasal breathing helps daytime alertness for a couple of reasons. First, it helps you to sleep better. When you breath through your nose during sleep, you prevent snoring, in addition to consuming the right amount of oxygen and ridding yourself from the right amount of Carbon dioxide (that’s right, CO2 is good for your normal physiology!) and a questionnaire filled by 3442 people via the Journal of Rhinology and Allergy reveals that people who had “chronic nasal obstruction,” had “significantly higher” sleepiness scores and lower Quality of life scores even adjusted for age, sex, and body mass index (10.2500/ajr.2007.21.3087).

Another questionnaire study from the Laryngoscope found, from 7,180 people:

“Younger subjects reported a higher degree of nasal obstruction. Subjects who reported a higher degree of nasal obstruction had higher daytime sleepiness and lower quality of life. Subjects with higher daytime sleepiness had lower quality of life. The degree of nasal obstruction was not associated with body mass index (https://doi.org/10.1097/01.mlg.0000239111.24094.a3).”

When you mouth breath, you breathe in too much oxygen and out too much CO2 (for lack of a deeper explanation). This means that your blood has lower CO2 levels which is bad for blood pH (acidity), and nutrient diffusion.

Your body, in moments like these can pass out, but more importantly, if you mouth breath during sleep, you can foster apneic spells which means your quality of sleep will go down and of course your daytime alertness crashes too (10.1152/jappl.1988.65.4.1520).

Another study packed the noses of people – in order to mimic an allergic environment – with and without sleeping disorders and found that mouth breathing was induced by packing the nose. The downstream results of which were causing or worsening the “sleep-disordered breathing in all patients and [nose packing] significantly increased the number, duration, and frequency of episodes for the group as a whole (10.1288/00005537-198107000-00015).”

3. It forms your face to be healthier and therefore more attractive

Mouth breathing causes what is called the “adenoid type face.” Which is due to a lot of adenoid tissue- a type of soft, immune tissue – in the nasopharynx . This review looks at the facial bones’ adaptation to mouth breathing and concludes that it causes “retroclination” of the teeth which points the teeth outward, “long narrow faces,” and excess adenoid tissue. (https://doi.org/10.1043/0003-3219(1980)050<0147:ORFMAC>2.0.CO;2)

The same review found that the back of hard palate (the hard part at the top of your mouth, that connects to the soft part of the top of your mouth) “seems to deviate in a downward direction.” This is related to a simultaneous “comparatively greater anterior lower facial height.”

A different study concludes that when the breathing pathway through the nose is obstructed many facial abnormalities occur, including, “narrow faces, narrow mouths, high palatal vaults, dental malocclusion, gummy smiles, and many other unattractive facial features, such as skeletal Class II or Class III facial profiles (PMID: 20129889).”

Did your dentist ever say you had malocclusion (when you bite, your teeth don’t match up properly)? Maybe you mouth breathed as a child! And Maybe with enough nasal breathing you can reverse it over a long period of time! This study says to recognize the mouth breathing problem at an early age, so parents, pay attention to how your children breath (PMID: 25881385)!

A wonderful review from International Journal of Pediatrics is titled “It Takes a Mouth to Eat and a Nose to Breathe: Abnormal Oral Respiration Affects Neonates' Oral Competence and Systemic Adaptation.” This review points out that “the resistance of air through the nasal passages has a formative effect on the nasal cavities.” Mouth breathing, this review claims, results in “long face syndrome,” and the atrophy of muscles associated with flaring the nostrils, and closing and opening the mouth.

4. It eases exercise-induces asthma symptoms, and regular asthma attacks

“The major cause of exercised induced asthma (EIA),” writes A R Morton, et al., from The University of Western Australia, “is thought to be the drying and cooling of the airways during the ‘conditioning’ of the inspired air.” From their comparative study they conclude that mouth breathing dries out the airways considerably more than does nose breathing.

This fact is explained by overall less air entering the airways (because of the longer pathway and the smaller diameter airway), and the air that does enter the airways is better “conditioned,” in other words, warmer and more humidified. Therefore, A.R. Morton, et. Al., state that nose breathing “will reduce the severity of EIA provoked by a given intensity and duration of exercise (PMID: 8599744).”

A systematic review and meta-analysis from Current Allergy and Asthma Reports shows that “mouth breathing was significantly associated with asthma,” and “mouth breathing compromises the heating, humidification, and filtration of inspired air and may aggravate asthma.” This aggravation would happen, the article claims, via the higher amount of allergens that reach the lungs, or by stimulating the nasobronchial neural reflex (https://doi.org/10.1007/s11882-020-00921-9).

Still, another study from the International Journal of Pediatric Otorhinolaryngology suggests that mouth breathing, due to nasal congestion, decreases the reaction of exercise induced bronchospasm (a feature of childhood asthma) in patients who have allergic asthma and rhinitis (10.1016/j.ijporl.2016.04.020).

Lastly, regarding the topic of nasal breathing and asthma, a review from Current Allergy and Asthma Reports showed that “Deep nasal breathing can induce bronchodilation in asthma attacks Sniff and gasp – like maneuvers may reverse central apnea (10.1007/s11882-008-0025-7).”

5. It forms and can increase the sense of smell

In college I learned about a very important concept called Wolff’s law which states that if you stress a part of the body, it will respond by adapting to be stronger. The inverse is also true, if you do not entertain the function of certain organs, they may atrophy which is what happens to our sense of smell when we do not breathe through our nose regularly.

“It Takes a Mouth to Eat and a Nose to Breathe...” states that, “Sensory deprivation due to early nasal obstruction has indeed repeatedly been demonstrated to alter both the structure of animals' olfactory tracts and related functions (10.1155/2012/207605).”

6. It can increase time-to-exhaustion during exercise

This meta-analysis put together in Frontiers in Physiology was done to note what the best strategy is to enhance running performance in humans (10.3389/fphys.2022.813243). The studies included in this meta-analysis, show that participants could perform nasal breathing up to 85% of their VO2max (cardio exercise effort) with no negative effects on their athletic performance.

In addition, it found that as long as there was an “adaptation period,” – period during which the study’s participants were instructed, familiarized, and practiced in working out with nasal breathing – there were lower breathing rates, but reduced hypocapnia (hyperventilation/too little CO2 in the blood), and increased nitric oxide (NO).

The paranasal sinuses in the back of nasopharynx (the back of the nose/above the throat) produce NO which is a vasodilator and a bronchodilator. The paranasal sinuses are not hit with air during mouth breathing (10.1016/j.micinf.2020.05.002).

The consequences of gaining nitric oxide by breathing through the nose, therefore, is that the lung can more efficiently collect air even though less air is being produced. The NO can also diffuse into the blood from the lungs, and therefore increase the efficiency of the internal veins, arteries, and capillaries in delivering oxygen and collecting carbon dioxide! Its like our nose was made for breathing!

The meta analysis also includes that, “While nasal breathing utilizes a smaller airway, which is a limitation at higher exercise intensities, it appears to increase diaphragmatic function (Trevisan et al., 2015), which could be a long-term advantage.”

It seems that at the highest intensities of exercise nasal breathing may not be the optimal way to collect air, but during training or recovery periods of high intensity workouts, it is important to train nasal breathing for all the other benefits!

The meta-analysis also recognizes that:

“Some studies have reported favorable performance effects, such as decreased respiratory exchange ratio, VO2, and increased running economy and time to exhaustion (Morton et al., 1995; Recinto et al., 2017). We estimate that these effects might benefically decrease RPE or dyspnoeic sensations, although direct study is required. Conversely, nasal breathing during heavy exercise leads to higher exercise HR [Heart Rate] and no difference in power output or anaerobic performance, perhaps as a result of greater inspiratory muscle load (Recinto et al., 2017).”

If that is a headache, let me explain. The decreased respiratory exchange ratio is the amount of oxygen traded for carbon dioxide. As already mentioned, mouth breathing usually over-trades. VO2 is the volume (volume) of oxygen (O2), and it is good to decrease it for the previously stated reason. These two effects plus the effects of increased diaphragm function and nitric oxide production and the reconstruction of the dental area overall lead to increased time to exhaustion (10.3389/fphys.2022.813243).

The increased running economy is basically an increase in the efficiency of your running form. RPE is the Rate of Perceived Exertion which indicates how much effort do you feel like you’re putting into running a given speed. If I could decrease the amount of effort into running a specific speed, I certainly would! The decreased RPE is seemingly influenced by the lack of difference in “anaerobic performance” (the burn in your legs) because of the greater inspiratory muscle load, which is, basically, the amount of oxygen to your muscles (one of the aforementioned effects of nitric oxide).

7. It increases cognitive (thinking) function

The meta-analysis from Frontiers in Physiology also indicates multiple studies that that breathing through the nose “at rest leads to improved cognitive function, emotional appraisal, memory, and lower perception of fear.” The increase in cognitive function of course is an effect by way of increased daytime alertness which was discussed above.

If you want your cognitive function to increase then you probably should get more oxygen to your head right? Well, forced expiration, which is a side effect of nose breathing seems to “benefit peripheral and central circulation and oxygenation.” The explanation for this benefit is that the abdominal muscles increase alveolar pressure and therefore “hyperperfuse” (push in oxygen) into the blood in the alveoli in the lungs.

Modern science seems to associate bipedalism (walking on two feet) with intelligence. This study indicates that the NO enriched air from nasal breathing, compared to mouth breathing, “induced a blood flow redistribution of about 4% of the total perfusion in the caudal to cranial and dorsal to ventral directions.”

The study is trying to say that the net increase in blood flow and oxygenation to the brain because of the NO from the paranasal sinuses increases parts of the brain associated with upright walking (https://doi.org/10.1152/japplphysiol.00285.2009). So, it is true that nasal breathing can even help with posture as an add-on to the increase in cognitive function!

Interestingly, a study supposes that many children who mouth breathe are “misdiagnosed with ADD or ADHD (PMID: 20129889).”

8. It makes breathing more efficient and adapts to the environment more quickly

Nasal breathing is more efficient than mouth breathing, which many people do not understand for this reason: you breathe in less air through your nose than through your mouth. Isn’t clean fresh air good for us? Don’t we need all the oxygen we can get? No, too much oxygen can kill you for multiple reasons.

One of the reasons which is protected against during nose breathing is the correct amount of CO2 in your blood.

This study found that your nose responds quite well and readily to warm vs. cold air. It says that, “The results confirm the previous observation that cold air breathed through the nose inhibits ventilation in normal subjects and show that this is not related to an increase in flow resistance. The reduction in ventilation is due to reduction in VT [Tidal Volume, the amount of air breathed into and out of the lungs in a normal breath] associated with shortening of the duty cycle (https://doi.org/10.1152/jappl.1988.64.1.371).”

The implications of this seem to be that the nose is a better organ to use than the mouth to adapt to various temperatures outside. The same interesting conclusion in this study is that the nose has receptors that even respond to different concentrations of specific gases such as oxygen and carbon dioxide (https://doi.org/10.1164/arrd.1984.129.5.687).

9. It helps to better prevent infections and fight respiratory infections

10. It betters heart rate variability

“The nasal mucosa is the first point of contact of the body with the inspired antigens and pathogens; therefore, crucial for the immune defense,” says the German Society of Oto-rhino-Laryngology, Head and Neck Surgery. The nose has tons of cells with cilia which help to catch germs and trap them in the mucosa. In addition, the nose synthesizes many Ig-A and Ig-G antibodies in its mucosa, which are immunoglobulins that are very cytotoxic which means they kill foreign microorganisms that attach to the nose’s surface. This amazing immune defense system in the nose is referred to as the MALT, or mucosa associated lymphoid tissue (10.3205/cto000113.)

One good predictor of if someone will be sick is their heart rate variability which adjusts according to difference stressors in the body. Along with nitric oxide reacting to various infectious organisms and viruses, longer exhales which are a product of nose breathing in relation to mouth breathing, “exploit respiratory sinus arrythmia to improve heart rate variability and subjective well-being at rest (10.3389/fphys.2022.813243).”

This is a fascinating passage from a nasal breathing study done in patients with COVID in the Scientific journal of Microbes and Infection:

“The rationale for using inhaled NO against SARS-CoV-2 infection stems from the fact that this molecule plays a major role in pulmonary and cardiovascular physiology. NO is a reactive oxygen species (ROS) that is continually produced by epithelial cells of the paranasal sinuses and nasopharynx via NO synthase (NOS) enzymes]. Produced at 10 parts per million (ppm) in the human sinuses, NO can diffuse to the bronchi and lungs, where it induces vasodilatory and bronchodilatory effects (10.1016/j.micinf.2020.05.002).”

The study adds that mouth breathing during sleep is more prevalent in males who are, as a result of mouth breathing, more likely to snore and also therefore, “more likely to develop respiratory tract infections.”

11. It helps with halitosis (bad breath)

12. It helps prevent tooth decay

Yes! Saliva helps remineralize the teeth (10.1590/S1678-77572012000500001)! Given this, it also makes sense that – warning fancy science word – halitosis is prevented or mitigated by breathing with the mouth shut where the saliva can marinade the teeth and the mouth. So perhaps its another reason to shut up and listen more!

13. It helps prevent aspiration (swallowing air)

Preventing aspiration is a function of using the nose to collect air which mandates the epiglottis be closed unless a serious – and rare – epiglottal malfunction is in place (10.1538/expanim1957.26.2_149). The side effects of aspiration, however, are quite serious. They include: acute respiratory acidosis (your blood becomes very and possibly, dangerously acidic), and elevation of the diaphragm, the first of which one can die from, the second, makes it harder to breathe (10.3109/00016489109137406).

In summary… BREATHE THROUGH YOUR NOSE!