James Nestor on How Bad Mouth Breathing Is
Mouth breathing is proverbial as a sign of being “uncool.” But in his very valuable book Breath, James Nestor argues that mouth breathing is also profoundly unhealthy. As one part of his argument, James writes convincingly of what a horrible experience it was for him when he subjected himself to the experiment of having his nose plugged for ten days. His account of an experiment on monkeys is also convincing:
Egil P. Harvold’s hideous experiments in the 1970s and 80s would not go over well with PETA or with anyone who has ever really cared for animals. Working from a lab in San Francisco, he gathered a troop of rhesus monkeys and stuffed silicone deep into the nasal cavities of half of them, leaving the other half as they were. The obstructed animals couldn’t remove the plugs, and they couldn’t breathe at all through their noses. They were forced to adapt to constant mouthbreathing.
Over the next six months, Harvold measured the animals’ dental arches, the angles of their chins, the length of their faces, and more. The plugged-up monkeys developed the same downward growth pattern, the same narrowing of the dental arch, crooked teeth, and gaping mouth. Harvold repeated these experiments, keeping animals obstructed for two years. They fared even worse. Along the way, he took a lot of pictures.
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Mouthbreathing, it turns out, changes the physical body and transforms airways, all for the worse. Inhaling air through the mouth decreases pressure, which causes the soft tissues in the back of the mouth to become loose and flex inward, creating less overall space and making breathing more difficult. Mouthbreathing begets more mouthbreathing. Inhaling from the nose has the opposite effect. It forces air against all those flabby tissues at the back of the throat, making the airways wider and breathing easier. After a while, these tissues and muscles get “toned” to stay in this opened and wide position. Nasal breathing begets more nasal breathing.
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Sleeping with an open mouth exacerbates these problems. Whenever we put our heads on a pillow, gravity pulls the soft tissues in the throat and tongue down, closing off the airway even more. After a while, our airways get conditioned to this position; snoring and sleep apnea become the new normal.
James also points to many ancient and traditional cultures that talk of the virtues of nose-breathing and the troubles with mouth-breathing. The most entertaining was his second-hand account of many Native American tribes:
Catlin would spend the next six years traveling thousands of miles throughout the Great Plains, covering more distance than Lewis and Clark to document the lives of 50 Native American tribes.
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The Native Americans explained to Catlin that breath inhaled through the mouth sapped the body of strength, deformed the face, and caused stress and disease. On the other hand, breath inhaled through the nose kept the body strong, made the face beautiful, and prevented disease. “The air which enters the lungs is as different from that which enters the nostrils as distilled water is different from the water in an ordinary cistern or a frog-pond,” he wrote.
Healthy nasal breathing started at birth. Mothers in all these tribes followed the same practices, carefully closing the baby’s lips with their fingers after each feeding. At night, they’d stand over sleeping infants and gently pinch mouths shut if they opened. Some Plains tribes strapped infants to a straight board and placed a pillow beneath their heads, creating a posture that made it much harder to breathe through the mouth. During winter, infants would be wrapped in light clothing and then held at arm’s length on warmer days so they’d be less prone to get too hot and begin panting.
All these methods trained children to breathe through their noses, all day, every day. It was a habit they would carry with them the rest of their lives. Catlin described how adult tribal members would even resist smiling with an open mouth, fearing some noxious air might get in. This practice was as “old and unchangeable as their hills,” he wrote, and it was shared universally throughout the tribes for millennia.
Some change in our behavior in the last few hundred years has made a big difference to the average shape of the human skull:
Every one of the ancient skulls was identical to the Parsee sample. They all had enormous forward-facing jaws. They had expansive sinus cavities and broad mouths. And, bizarrely, even though none of the ancient people ever flossed, or brushed, or saw a dentist, they all had straight teeth.
The forward facial growth and large mouths also created wider airways. These people very likely never snored or had sleep apnea or sinusitis or many other chronic respiratory problems that affect modern populations. They did not because they could not. Their skulls were far too large, and their airways too wide for anything to block them. They breathed easy. Nearly all ancient humans shared this forward structure—not just in the Morton Collection, but everywhere around the world. This remained true from the time when Homo sapiens first appeared, some 300,000 years ago, to just a few hundred years ago.
Evans and Boyd then compared the ancient skulls to the modern skulls of their own patients and others. Every modern skull had the opposite growth pattern, meaning the angles of the Frankfort plane and N-perpendicular were reversed: chins had recessed behind foreheads, jaws were slumped back, sinuses shrunken. All the modern skulls showed some degree of crooked teeth.
Later on in Breath, James points to a shift toward eating soft food that leads to facial underdevelopment as well as the (probably related) shift toward mouth-breathing as possible causes. I find the effects of soft food evolutionarily plausible: just as evolution could assume in the environment of evolutionary adaptation that we would go through frequent periods of very little food, and design some repair processes to happen then, evolution could design facial development based on the assumption—reasonable for the environment of evolutionary adaptation of humans—that we would be eating a lot of tough-to-chew food.
I find myself convinced by James Nestor’s arguments that nose-breathing is better for me than mouth-breathing. So much so that I want to encourage myself to do nose-breathing in the way that requires as little conscious attention as possible: making sure I breathe through my nose at night. This is a straightforward matter of an intervention James discusses: taping my mouth shut at night. I know it seems weird, but I have gotten used to it quite quickly. It is important to have the right kind of tape, or pulling it off in the morning will hurt. This is what I use:
Link to the Amazon page for this microfoam tape: “3m microfoam tape 2" x5 1/2 yd, stretched box: 6”
I use the Hitler-mustache taping: a narrow (2” wide) vertical strip in the middle of my lips. That way, if I get thirsty at night, I can drink through a straw through the corner of my mouth without having to remove the tape.
I can report that, subjectively, I feel better with the additional nose breathing. I feel better especially right when I wake up in the morning. I know this intervention needs more in the way of randomized controlled trials to document whether it has genuine benefits, but I would be optimistic about the results of such randomized controlled trials. (James reports some amount of relevant evidence that has been collected, though I don’t remember exactly a randomized controlled trial of mouth-taping at night.)
I confess, before I read it, I thought the theme of Breath—that we are breathing all wrong—sounded weird. And having read it, I am now doing an additional weird thing. But I found myself convinced of most (though not all) of what the book claimed. I recommend it. I plan to follow up with posts on some other ideas from Breath.