How To Strengthen Your Immune System By Breathing Through Your Nose

When it comes to strengthening your immune system, many factors may immediately come to mind: what we eat, how we exercise, which herbs and supplements we take. What about the way we breathe?  

Here's the short answer: Our nasal passages are able to filter bacteria and viruses in the air. We have little hair follicles in our nose (in fact, we have as many hair follicles inside our nose as we do on our head, according to Mackenzie) that are able to filter the air as you inhale, which can block dust and bacteria from reaching your lungs. 

Now, those nasal passages can only do so much: Studies have shown that, yes, our nasal cavity can filter out some particles1—those particles just have to be smaller than a certain diameter. Nonetheless, our noses can function as a great particle grabber; those particles are then either blown into a tissue when you sneeze or killed by your stomach when you swallow the mucus (as gross as it sounds, Mackenzie notes you swallow tons of mucus throughout the day).

Our mouths, on the other hand, don't have the same knack for filtering out particles. "There's a large amount of air that passes and goes right in the lungs," Mackenzie says. That's why you may wake up in the morning with "dry mouth," especially if you're one to fall asleep with your mouth hanging wide. 

So our noses and immune systems are inherently linked (our noses even have their own microbiome!), which might make you more conscious of your own breath, especially if breathing through your mouth feels more natural to you. While you can breathe out of your mouth occasionally, Mackenzie notes at least 80% of your day should be through your nose only. 

How do you reach that 80%? No need to do the math: Simply be more aware to shut your mouth throughout the day, he says—especially while exercising, when we typically huff and puff through our mouths. Perhaps try to keep your mouth closed through an entire yoga class; notice when you feel the urge to open up, and try to strengthen your nasal breathing by pushing through it. "Start to understand where the intensity factors play," Mackenzie says. "Then take it to a new level."