Inhaling through the left nostril has the opposite effect: it works as a kind of brake system to the right nostril’s accelerator. The left nostril is more deeply connected to the parasympathetic nervous system, the rest-and-relax side that lowers temperature and blood pressure, cools the body, and reduces anxiety. Left-nostril breathing shifts blood flow to the opposite side of the prefrontal cortex, the right area that plays a role in creative thought, emotions, formation of mental abstractions, and negative emotions.
In 2015, researchers at the University of California, San Diego, recorded the breathing patterns of a schizophrenic woman over the course of three consecutive years and found that she had a “significantly greater” left-nostril dominance. This breathing habit, they hypothesized, was likely overstimulating the right-side “creative part” of her brain, and as a result prodding her imagination to run amok. Over several sessions, the researchers taught her to breathe through her opposite, “logical” nostril, and she experienced far fewer hallucinations.
Our bodies operate most efficiently in a state of balance, pivoting between action and relaxation, daydreaming and reasoned thought. This balance is influenced by the nasal cycle, and may even be controlled by it. It’s a balance that can also be gamed.
There’s a yoga practice dedicated to manipulating the body’s functions with forced breathing through the nostrils. It’s called nadi shodhana—in Sanskrit, nadi means “channel” and shodhana means “purification”—or, more commonly, alternate nostril breathing.
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I’ve been conducting an informal study of alternate nostril breathing for the past several minutes.
It’s the second day of the nasal breathing “Recovery” phase, and I’m sitting in my living room, my elbows on the cluttered dining room table, softly sucking air through my right nostril, pausing for five seconds, and then blowing it out.
There are dozens of alternate nostril breathing techniques. I’ve started with the most basic. It involves placing an index finger over the left nostril and then inhaling and exhaling only through the right. I did this two dozen times after each meal today, to heat up my body and aid my digestion. Before meals, and any other time I wanted to relax, I’d switch sides, repeating the same exercise with my left nostril open. To gain focus and balance the body and mind, I followed a technique called surya bheda pranayama, which involves taking one breath into the right nostril, then exhaling through the left for several rounds.
These exercises felt great. Sitting here after a few rounds, I sense an immediate and potent clarity and relaxation, even a floatiness. As advertised, I’ve been entirely free of any gastroesophageal reflux. I haven’t registered the slightest stomach ache. Alternate nostril breathing appeared to have delivered these benefits, but these techniques, I’d found, were usually fleeting, lasting only 30 minutes or so.
The real transformation in my body over the last 24 hours came from another practice: letting my nasal erectile tissues flex of their own accord, naturally adjusting the flow of air to suit the needs of my body and brain. It happened because of simply breathing through my nose.
As I’m quietly contemplating all this, Olsson comes barging in. “Good afternoon!” he yells. He’s wearing his shorts and Abercrombie sweatshirt, and he plops down across from me while placing a blood-pressure cuff around his right arm. This is the same position he’s assumed for the last eleven days straight, in pretty much the same clothes. Today, however, there’s no bandage, nose clip, or silicone plugs up his nose. He’s also breathing freely through his nostrils, taking in easy and silent inhales and exhales. His face is flushed, he’s sitting upright, and he’s so keyed up with energy that he can’t stay still.
I figured that some of our new, bright outlook on life was psychosomatic until a few minutes later, when we checked our measurements. My systolic blood pressure had dropped from 142 ten days ago—a deep state of stage 2 hypertension—to 124, still a bit high but just a few points from a healthy range. My heart rate variability increased by more than 150 percent, and my carbon dioxide levels rose around 30 percent, taking me from a state of hypocapnia, which can cause dizziness, numbness in the fingers, and mental confusion, and placing me squarely within the medically normal zone. Olsson showed similar improvements.
And there’s potential for much more. Because pulsing nasal cycles are only a small part of the nose’s vital functions.
Imagine for a moment that you’re holding a billiard ball at eye level a few inches from your face. Then imagine slowly pushing that entire ball inside the center of your face. The volume the ball would take up, some six cubic inches, is equivalent to the total space of all the cavities and passageways that make up the interior of the adult nose.
In a single breath, more molecules of air will pass through your nose than all the grains of sand on all the world’s beaches—trillions and trillions of them. These little bits of air come from a few feet or several yards away. As they make their way toward you, they’ll twist and spool like the stars in a van Gogh sky, and they’ll keep twisting and spooling and scrolling as they pass into you, traveling at a clip of about five miles per hour.
What directs this rambling path are turbinates, six maze-like bones (three on each side) that begin at the opening of your nostrils and end just below your eyes. The turbinates are coiled in such a way that if you split them apart, they’d look like a seashell, which is how they got their other name, nasal concha, after the conch shell. Crustaceans use their elaborately designed shells to filter impurities and keep invaders out. So do we.
The lower turbinates at the opening of the nostrils are covered in that pulsing erectile tissue, itself covered in mucous membrane, a nappy sheen of cells that moistens and warms breath to your body temperature while simultaneously filtering out particles and pollutants. All these invaders could cause infection and irritation if they got into the lungs; the mucus is the body’s “first line of defense.” It’s constantly on the move, sweeping along at a rate of about half an inch every minute, more than 60 feet per day. Like a giant conveyor belt, it collects inhaled debris in the nose, then moves all the junk down the throat and into the stomach, where it’s sterilized by stomach acid, delivered to the intestines, and sent out of your body.
This conveyor belt doesn’t just move by itself. It’s pushed along by millions of tiny, hair-like structures called cilia. Like a field of wheat in the wind, cilia sway with each inhale and exhale, but do so at a fast clip of up to 16 beats per second. Cilia closer to the nostrils gyrate at a different rhythm than those farther along, their movements creating a coordinated wave that keeps mucus moving deeper. The cilia grip is so strong that it can even push against the force of gravity. No matter what position the nose (and head) is in, whether it’s upside down or right-side up, the cilia will keep pushing inward and down.
Working together, the different areas of the turbinates will heat, clean, slow, and pressurize air so that the lungs can extract more oxygen with each breath. This is why nasal breathing is far more healthy and efficient than breathing through the mouth. As Nayak explained when I first met him, the nose is the silent warrior: the gatekeeper of our bodies, pharmacist to our minds, and weather vane to our emotions.