Updated: Oct 15, 2021
It may feel unnatural at first, but it’s the best thing for your body
Breathing easily has always been a vital part of well-being. Thanks to the pandemic, however, this simple biological function has been compromised for many infected people, and remains threatened for everyone else who’s susceptible to getting Covid-19.
But what if changing the way you breathe could potentially help protect you from the very thing that threatens your ability to breathe? That’s one theory some experts are suggesting. It has to do with the simple physiology of the nose, and the chemical compound nitric oxide (NO).
Aside from filtering, warming, and humidifying the air you breathe, the nose is your first line of defense against allergens and pathogens. The mucus and cilia inside are designed to block these outside invaders from going farther down the respiratory tract and making you sick. And NO, which is what the sinuses release when you breathe through your nose, is a vasodilator, meaning it relaxes the blood vessels and lowers blood pressure.
Doctors have been giving NO gas to people long before Covid-19 to help improve lung function in critically ill people suffering from adult respiratory distress syndrome (ARDS), according to Albert Rizzo, MD, Chief Medical Officer for the American Lung Association. There are currently 11 clinical trials in the U.S. and Canada testing whether administering NO can improve recovery time of people with Covid-19 by boosting oxygen levels. The gas may also help fight respiratory tract infections like Covid-19 by inactivating viruses and inhibiting their replication.
Several studies, including one from 2004 that focused on the effects of inhaling NO on the SARS coronavirus, have shown that the compound has antiviral properties. A recent analysis of 45 relevant studies supports this oxygenation boosting effect that North American researchers are trying to demonstrate. It also notes that naturally produced NO from nasal breathing seems to have similar antiviral effects. For example, one discussed study found that humans who exhale more NO have fewer common cold symptoms, which suggests that nasally-produced NO may help protect humans from other respiratory viruses like Covid-19.
“Your lungs do have to work harder at accessing the oxygen in the air that you’re breathing in through your mouth versus your nose.”
Conversely, habitual mouth breathing may actually increase susceptibility to the virus as well as its level of severity, according to the May analysis. It states that mouth breathing during sleep may worsen the symptoms of Covid-19, just as it worsens other respiratory illnesses like the common cold and the flu.
“You do lose some of the benefit of the filtering mechanisms and potentially some of the triggering of the immune system that might be triggered by particles that go through the membranes of the nose,” says Rizzo.
People tend to breathe more through their mouths when they’re stressed or their body is working hard, because it feels like you’re getting more air that way. However, according to Zara Patel, MD, a rhinologist and otolaryngologist at Stanford Medicine, the lungs can’t utilize this air as effectively, because it’s not warmed or humidified as it is when you breathe through your nose.
“Your lungs do have to work harder at accessing the oxygen in the air that you’re breathing in through your mouth versus your nose,” says Patel.
We’re all guilty of occasional mouth breathing, but a number of people are habitual mouth breathers out of necessity, due to an obstruction, abnormal sinuses, or chronic sinus congestion, to name a few potential conditions. According to Patel, some individuals are relatively uninhibited by habitual mouth breathing, but others end up developing side effects that range from uncomfortable to potentially detrimental.
Some of the milder effects include difficulty falling and staying asleep, dry mouth and throat, gum disease, bad breath, and snoring. The more long-term potential effects are changes in jaw shape and position and chronic respiratory problems such as sleep apnea, which can lead to pulmonary and cardiovascular complications down the road. “Your blood pressure, specifically in your pulmonary arteries, tends to go up over time if you have untreated sleep apnea, and that can lead to increased stress on your cardiovascular and pulmonary systems,” says Patel.
Author and journalist James Nestor became familiar with some of these effects within days of voluntarily plugging his nose as part of experimental research for his book, Breath: The New Science of a Lost Art. With the help of Jayakar Nayak, MD, an otolaryngologist at the Sinus Center at Stanford University who also runs a sinus research lab, Nestor conducted an informal study to find out what happens to the body when you only breathe through your mouth for an extended period of time.
“I said, ‘that’s going to be absolute torture for you, but I’m happy to do it,’” recalls Nayak. Aside from helping him block his nose comfortably using clips, Nayak monitored Nestor’s vitals regularly. “He wanted to make it as scientifically valid as possible,” says Nayak.
The experiment was initially supposed to last a month. Nestor could only make it 10 days.
Humans were designed to breathe through our noses, and Patel and Rizzo agree, nasal breathing is better than mouth breathing due to its filtration system and immune response.
“My blood pressure went up 20 points in the first day or two,” recalls Nestor. “I went from not snoring at all or snoring just a couple minutes throughout the night to snoring four hours a night.” According to Nestor, he eventually developed sleep apnea to the point where his blood/O2 levels hit 90–91% (the normal range is 95–100%). He even developed a nasal infection. A friend who did the experiment with him experienced nearly identical effects.
What was perhaps most interesting about the informal study was what happened when Nestor and his friend resumed nasal breathing. According to Nestor, almost immediately, their sleep apnea and snoring dissipated, and was completely gone within four days.
Humans were designed to breathe through our noses, and Patel and Rizzo agree, nasal breathing is better than mouth breathing due to its filtration system and immune response. However, over the centuries, perinasal sinuses and noses have shrunk, leading to more and more nasal breathing problems. For example, over 25 million Americans suffer from sleep apnea. That said, even though some nasal obstructions require surgical intervention, for the majority of people, there are steps to take to make nasal breathing easier.
These steps depend on whether you’re dealing with a blocked nose or simply a habit of mouth breathing. If the latter, start by becoming more aware of your breath. “It’s a conscious effort that you have to make in order to retrain what might have been a bad habit that you developed,” says Rizzo.
If you have chronic sinus congestion, Patel says to start by regularly flushing your nose with saline spray, which can be found at most drug stores. This helps moisten the nasal cavities and flushes out dust and other allergens. You can pair it with an inhaled decongestant spray if needed, but Patel cautions against just grabbing something over the counter, as some sprays have proven to be harmful over time, and instead advises consulting an ENT before buying. An ENT can also help you identify the source of your congestion, like a particular allergy, so the congestion can be treated more efficiently.
For people who think they have sleep apnea, Patel recommends participating in a sleep study (which you can do in the comfort of your own home), and if the results indicate sleep apnea, investing in a CPAP (Continuous Positive Airway Pressure) machine, which helps normalize breathing by opening up airways and even reducing inflammation in the nose.
Once the underlying cause of mouth breathing is rectified, you can try to more consciously breathe through your nose until it becomes second nature. “Mouth breathers should be encouraged to take a sip of water every hour and challenged to close their mouth afterwards,” as a nasal breathing practice says Joi Lucas, MD, a pediatric pulmonologist at Lakeland Regional Hospital in Florida. She also recommends setting an alarm as a reminder, and practicing slow, deep nasal breathing exercises periodically.
Nasal breathing will not ward off viruses like Covid-19 on its own, but it is one of your body’s built-in defense mechanisms against them. It should also just make you feel better all around. Considering the state of things, there’s no better time to make it a habit.