George Catlin was an American painter from the 19th century who painted Native Americans in their native territories. In his book, “Shut Your Mouth and Save Your Life,” Catlin noted that people who breathe with their mouths open are more prone to various health ailments. You see evidence of this in our current society, such as in children with ADHD, who are often mouth breathers. If you look at people in the highest levels of academia and politics, you almost never see an open mouth posture.
So why is mouth breathing bad for you? Here are 5 reasons:
1. Missing out on NO
NO stands for nitric oxide, which is a gas is that it dilates blood vessels in the body. Three US scientists received the Nobel prize in Physiology and Medicine in 1998 for describing NO’s role in cardiovascular and nervous system signaling. It also happens to be made in the sinuses, and can help to increase oxygen intake in the lungs by dilating blood vessels. So by breathing through your mouth, you’re missing out on 10 to 20% additional amounts of oxygen. As a results, you’ll compensate by breathing a bit faster and more shallow, essentially hyperventilating. This can cause your carbon dioxide levels to drop, raising blood pH levels, and preventing oxygen from being released as easily to your body’s tissues. (See my interview with Patrick McKewon on Buteyko Breathing).
2. Mouth Breathing Can Cause Crooked Teeth
It’s common convention in the dental and medical communities that breathing through your mouth prevents your face from developing properly. One extreme example is called adenoid facies, which is results in open mouth and head forward posture, long, narrow face, high arched hard palate, recessed lower jaw, and chronic nasal congestion. In monkey studies, plugging the nose during development has been shown to significantly retard facial growth. Having smaller jaws will make you much more susceptible to sleep-related breathing disorders.
Preventing proper jaw development can lead to dental crowding and narrowing of the airways downstream in the throat. This is why it’s important to address nasal congestion aggressively when applying braces for children.
3. Mouth Breathing Can Cause Cavities
Too much sugar in our diets and bacterial in our mouths are commonly blamed for cavities. However, having a dry mouth due to mouth breathing can lead to a cascade of conditions that sets up the perfect storm: Saliva reduces acid levels, and can help to prevent plaque buildup. If you have smaller jaws to begin with, you’re more likely to have sleep-related breathing disorders, which predisposes you to have acid being suctioned up from your stomach every time you stop breathing. Your stomach juices not only contain acid, but also bile, bacteria and digestive enzymes. These substances have also been shown to reach your sinuses, ears and lungs. In addition, the same situation can set you up for gun disease.
4. Mouth Breathing Can Cause A Deviated Septum
I describe how mouth breathing can cause a deviated nasal septum in my last blog post. Smaller upper dental arches will crowd the nasal cavity and cause the nasal septum to buckle to one side or the other, due to a high arched hard palate.
5. Mouth Breathing Causes Tongue Collapse
Do you ever wonder why it’s harder for you to breathing when lying down in a dentist’s chair with your mouth wide open? You may think that you can breathe better if you open your mouth, but it’s the reverse. Opening your mouth causes your tongue to fall back, preventing proper breathing. Here are photos of someone with the mouth open and closed. The photo on the left is the space behind the tongue with the mouth open. Your can see the tongue and lingual tonsil blocking the breathing, with the hole being smaller than the size of a small straw. On the right is the same person with her mouth closed. You can see that the tongue base has moved forward along with the epiglottis, all the way to the top of the photo.
This is why people who snore typically keep their mouths open, and closing the mouth using a chin strap can sometimes help with snoring.
Shut Your Mouth And Save Your Life
There are countless papers and research studies describing the negative health consequences of mouth breathing. Even without all this data, traditional cultures have been promoting the value of closed-mouth nasal breathing. In Korean culture, mothers have been telling their children to keep their mouth closed for generations. It’s likely you’ll find similar findings in other cultures as well. If you want to learn what these health consequences are, I recommend you read my book, Sleep Interrupted: A physician reveals the #1 reason why so many of us are sick and tired.