Breathing, particularly nasal breathing, is having a moment. Consider, between COVID-19, the weak economy and political conflicts, we’re reminded to breathe deeply through our noses to lessen anxiety. And a new book on breathing quickly hit The New York Times bestseller list.

“Breathing is a missing pillar of health, and our attention to it is long overdue,” writes journalist James Nestor, author of Breath: The New Science of a Lost Art, in The Wall Street Journal. “How we breathe matters. … The way we take in that air and expel it is as important as what we eat, how much we exercise and the genes we’ve inherited. This idea may sound nuts, I realize.” Nestor interviewed neurologists, rhinologists and pulmonologists at Stanford, Harvard and other institutions, saying, “What they’ve found is that breathing habits were directly related to physical and mental health.”

Our bodies were designed to breathe through our noses. When we sleep, our body naturally alternates between breathing through the left and right nostrils, and through this process, regulates our body’s functions, says rhinologist Dr. Belachew Tessema, associate clinical professor in the division of otolaryngology at the UConn School of Medicine. Breathing through our mouths disrupts our body’s normal function, so he suggests people look at nasal breathing as a way to prevent several chronic maladies.

“If we don’t have normal nose breathing, we can’t sleep,” says Tessema, ENT physician at ProHealth Physicians. “Your nose controls your sleep. Snoring is a sign of nasal dysfunction. I think of the nose as the bastard child of the lung. The nose is the gateway to our body’s physiological functioning.”

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Benefits of nasal breathing: 

Improved sleep quality. That, in turn, improves all the functions that rely on a good night’s sleep. If you wake up with a dry mouth or suffer from bad breath, those are your body’s signs that something is wrong, Tessema says. If someone sleeps with their mouth open, that could be a sign they have sleep apnea, says Dr. Greg Katz, a cardiologist with Nuvance Health.

Less anxiety. Breathing slowly through the nose triggers a relaxation response. “Nose breathing also slows the breath down because it provides more resistance and this has a direct effect on the nervous system,” says Anne Dutton, director of the Yale Stress Center mindfulness education program. “Specifically, slower breathing activates the parasympathetic nervous system, reducing anxiety and signaling the body to calm down.”

Lower blood pressure. Nasal breathing is associated with more relaxed breathing, and lowering our blood pressure benefits our cardiovascular health, Katz says. When people meditate, they engage in focused nasal breathing, Tessema says. “Mouth breathing is associated with negative health outcomes such as elevated blood pressure, decreased heart-rate variability, elevated pulse, poor sleep quality, and fatigue. It stresses the body,” Dutton says. “Breathing through the nose, on the other hand, releases hormones that help to maintain a state of balance in the body by regulating blood pressure, as well as monitoring and adjusting the heart rate.”

Improved cardiovascular function. When the body doesn’t function as it’s designed — such as breathing through our noses — it begins to dysregulate and move away from optimal function, Tessema says. Nasal breathing is a normal physiological function; when you lose it, he says, it shows up different ways in different people — for some people that’s high blood pressure and for others it’s headaches. Oral breathing, says Katz, the cardiologist, is “a marker that would make me worry about cardiovascular disease.”

Stored memories in our bodies. If the nose is obstructed and we can’t breathe through our nostrils, we can’t take in the chemicals behind the smells and get them into the olfactory cleft; and therefore, our bodies can’t activate the memory storage that is secondary to smell, Tessema says.

Filtering of allergens, virusesand other particles. Working as our body’s filter, nasal breathing prevents unwanted intruders from reaching the lungs in a way that mouth breathing doesn’t, says Dr. R. Peter Manes, a Yale School of Medicine rhinologist and skull-based surgeon. If you feel you can’t breathe well through your nose, or can only breathe through one side of your nose, Manes and Tessema recommend seeing your primary care physician.

Better oral hygiene. Nasal breathing humidifies the air as we breathe it in. When we breathe through our mouths, our oral cavity dries up, which can lead to significant dental issues. Mouth breathing also causes bad breath, which is caused by bacteria in the mouth, also bad for oral health.

How to improve your nasal breathing

“Concentrating on the act of nasal breathing can help you transition from mouth breathing,” Yale’s Manes adds. Depending on the cause of the nasal obstruction, people can try a nasal steroid spray or Breathe Right nasal strips to open their nose at night, he says. Sometimes people have trouble breathing from their noses because they’re congested due to a cold or allergies. A safe and effective method to clear a congested nose is nasal rinsing, doctors say. Manes recommends nasal saline irrigations using boiled tap water or distilled water, baking soda and salt. “There are many products available that provide this,” he says. “Personally, I tend to recommend NeilMed Sinus Rinse. I think the delivery system is intuitive and easy to handle.”

What about masks?

There is no scientific evidence that mask wearing negatively impacts breathing, says Nuvance Health’s Katz. He used a pulse-oxygen device to measure his oxygen levels while wearing various masks — cloth, surgical, N95 and an N95 mask paired with a surgical mask. “I’m 100 percent certain no type of mask lowers your oxygen levels,” he says.

The COVID-19 connection

Doctors know that parts of the immune system that help defend against viruses exist in the nasal cavity. While nasal breathing appears to protect against viruses, there is no definitive scientific research linking nasal breathing with protecting against COVID-19, says Yale’s Manes.

However, UConn Health faculty recently published a research paper in the American College of Prosthodontics Journal of Prosthodontics finding that rinsing the mouth and nose with a diluted version of over-the-counter povidone-iodine (PVP-I) can kill viruses like coronavirus and prevent transmission in as little as 15 seconds.

UConn’s Tessema, also an ENT physician at ProHealth, recommends using 9.5 ml of water and 0.5 ml of a commercially available 10 percent PVP-I antiseptic solution to create a 0.5 percent diluted solution, according to a story in UConn Today. Dilute the solution immediately before rinSing and rinse for a minimum of 30 seconds. People who are allergic to iodine, who are pregnant or have thyroid problems should not use it, however.

“If it killed SARS and MERS, why wouldn’t it kill SARS-CoV-2?” Tessema says. In addition to using masks, he recommends nasal and oral rinsing as a way to kill the coronavirus before it can spread from the nose or the mouth into the lungs. He’s so convinced of this that, to protect his family, his patients and himself, Tessema does both an oral and nasal rinse at the end of his workday and before coming to work in the morning, he says. Viruses take 10 to 12 hours to infect the cells. “That’s why I do it [the nasal and oral rinse] twice a day,” he says.

As a diluted iodine alternative, a Yale School of Medicine infectious disease doctor suggests salt water gargling and saline nasal rinses for potentially preventing the spread of the coronavirus. “We know that the SARS-CoV-2 virus takes hold in the nose and throat,” says Dr. Manisha Juthani, associate professor of medicine at Yale. “We can’t say for sure, but gargling and nasal rinsing may disrupt the ability of the virus to establish itself and cause infection. … It is a low-risk intervention with potential benefit.”

Nasal breathing and exercise

Anyone who has ever sprinted or pedaled their bike up a steep hill knows how hard it is to breathe through their nose during heavy exertion. But nasal breathing during exercise can boost athletic performance.

Breathing through the nose releases more nitric oxide into the blood, says Dr. Elizabeth Gardner, a Yale School of Medicine sports medicine doctor. Nitric oxide is a potent “vasodilator,” expanding the blood vessels and ensuring that more oxygen gets to the muscles that need it, she says. The nasal passages are smaller than those in the mouth, so it takes more time for air to be expelled through the nose, which gives the lungs more time to extract oxygen from the air and move it into the bloodstream to go to tissues in the body, she says. 

Nasal breathing stimulates the “rest and digest” system, known as the “parasympathetic” nervous system, rather than the “fight or flight” system, she says, so “it can induce a sense of calm, even in the midst of stressful, high-intensity activity. This has the potential to improve focus and even, potentially, performance.” 

In addition, when we breathe through our nose during exercise, we open up our vocal cords and let in another 2 millimeters of air than we would if breathing through our mouth, says Dr. Denis Lafreniere, professor and chief of the otolaryngology division at UConn Health. Breathing through our nose delivers moisture to the air we breathe in, optimizing our body’s functions, he says. Our nose, throat and lungs have cilia, which moves mucus up our noses and sinuses. When breathing dry air, the mucus gets sticky and tacky and can start to block our airwaves, Lafreniere says. 

That doesn’t mean that when working out intensely we can’t breathe through our mouths, says Dr. Greg Katz, a cardiologist with Nuvance Health. “It’s much more important to your health whether you’re exercising or not as to whether you breathe through your nose or mouth.”

This article appears in the September 2020 issue of Connecticut MagazineYou can subscribe to Connecticut Magazine here, or find the current issue on sale hereSign up for our newsletter to get our latest and greatest content delivered right to your inbox. Have a question or comment? Email editor@connecticutmag.com. And follow us on Facebook and Instagram @connecticutmagazine and Twitter @connecticutmag.