If you’ve ever been in a state of sheer panic, someone may have told you to “take a deep breath” to calm yourself down.
This is good science-based advice. A cluster of nerve cells in the brain links breathing to different emotional states. When we’re very anxious, we breathe fast and unevenly, while slow, deep, steady breathing brings on calm.
But today I’ve got even better advice: “Take a deep breath through the nose.” And not just when you’re upset, but all the time. Here’s why. . .
Science now shows that nasal breathing has a strong influence on key brain organs. This not only affects emotions but how well we retain memories.
Believe it or not, this is becoming a big thing in health, because so many of us breathe through the mouth, especially when we’re sleeping. The epidemic of sleep apnea, allergies and sinus problems has made us into a nation of mouth-breathers. And by the way, mouth-breathing is related to snoring, and it’s a tipoff that you’ve got both problems.
Mouth breathing and/or snoring are linked to. . .
- Lower levels of nitric oxide needed to protect against viruses, bacteria and fungi in the sinuses and nose
- Worse sexual function due to low nitric oxide
- Increase of bacteria in mouth due to dry mouth
- Gum disease and cavities due to dry mouth
- Poor lung function due to drier air, lower nitric oxide and less oxygen
- Increased blood pressure due to less nitric oxide
- Thicker carotid artery due to trauma from snoring
- Higher anxiety and higher levels of stress chemicals like cortisol
- Poor filtering of bacteria, pollen, and dust, causing allergic reactions and inflammation of sinuses
But for now, let’s get back to memory. . .
Inhaling Stimulates Brain Activity
Researchers at Northwestern University Feinberg School of Medicine, Chicago, were interested in how breathing affects three parts of the brain: the amygdala, hippocampus and olfactory cortex. These areas are tied to emotional processing, memory and sense of smell, respectively.
The scientists recruited 33 healthy volunteers aged 18 to 30 to have their brain activity monitored. They were split into separate groups and induced to breathe either through the nose (by taping up their mouths) or the mouth (by clipping their noses). They were then shown 180 everyday objects on a computer screen for 15 minutes (this was called the encoding stage, referring to formation of the memories).
Following a 20 minute break – the consolidation stage – the volunteers were shown the pictures again plus 180 new pictures. They were asked whether they had previously seen the images presented (retrieval stage).
The research group found that participants encountering the image while breathing in through the nose had significantly better recall than when they viewed it while exhaling. They also outperformed the mouth breathers.
Christina Zelano, assistant professor of neurology who led the research, commented, “One of the major findings in this study is that there is a dramatic difference in brain activity in the amygdala and hippocampus during [nasal] inhalation compared with exhalation.
“When you breathe in [through the nose], we discovered you are stimulating neurons in the olfactory cortex, amygdala and hippocampus, all across the limbic system. And these changes in brain activity also lead to cognitive changes over the course of the breathing cycle as well.”
The study findings suggest we’ll have better retention of new material as we breathe in through the nose. Following this method to the letter would double the time it takes to read or listen to new material.
I suspect there won’t be a rush to use this memory tip, but it might be a useful aid when there is one particular thing you really want to remember (like your keys, or to mail a letter).
It does at least demonstrate the importance of nasal rather than oral breathing.
Nose Breathers’ Vastly Better Recall of Odors
A new study from Sweden focused on the less appreciated second memory stage, consolidation. Conducted by scientists at the Karolinska Institute, it has just been published in the Journal of Neuroscience.
The study included 24 men and women aged 19 to 25 who were presented with six well known fragrances and six others that were likely to be new to them. They then rested for an hour. During this consolidation period, half breathed through the mouth while the other half breathed through the nose.
When this finished, they were presented with the previous odors plus a new set of six familiar and six unfamiliar ones – 24 odors in total so far.
It turned out the people who had breathed through the nose during the rest period/consolidation phase were nearly twice as successful at recognizing whether they were sniffing a previous or new scent when compared to the mouth breathers.
Leading the research team was Professor Artin Arshamian, who said, “Memories pass through three main stages in their development – encoding, consolidation, and retrieval.
“Breathing through the nose compared to the mouth during consolidation enhances recognition memory. This demonstrates…that nasal respiration is important during the critical period where memories are reactivated and strengthened.
“These results provide the first evidence that respiration directly impacts consolidation of episodic events and lends further support to the notion that core cognitive functions are modulated by the respiratory cycle.”
Things You Can Do to Improve Breathing
Since there are many adverse consequences from chronic mouth breathing and at least 30 benefits from nose breathing, if you are one of the estimated third to half of adults who breathe through the mouth at least some of the time, you might wish to consider breathing retraining – and getting sinus conditions corrected.
Some retraining methods to investigate are Buteyko, Papworth and Pranayama yoga.
Other research shows that a lot of our memory retention occurs at night, when memories stored in the hippocampus during the day are moved to permanent storage in other parts of the brain. It’s known that poor sleep disrupts this process and contributes to memory loss.
Now it looks like even if you sleep well, breathing through the mouth at night, as so many of us do, may be throwing yet another wrench into the memory process. This guess goes beyond the studies described above, but it seems worth investigating.