Breathe in, breathe out. It's automatic, instinctual. But the way you breathe may be impacting your brain more than you realize. A groundbreaking study has revealed that breathing through your mouth could be hindering your cognitive abilities, while nasal respiration provides a neural boost
We all do it over 20,000 times a day,1 mostly without a second thought - breathing. However, researchers from Gachon University in South Korea have discovered that how we breathe can significantly impact our brain function, especially when it comes to memory and thinking tasks.
In the study, published in the journal Healthcare, 22 healthy participants were asked to perform a challenging working memory exercise called the 2-back task. This involves viewing a series of numbers and indicating when the current number matches the one from two steps earlier. The volunteers completed the task while breathing either through their nose or mouth, as their brain activity was measured using functional magnetic resonance imaging (fMRI).
The fMRI scans revealed that during oral breathing, there was reduced activation in several brain regions normally engaged during working memory, such as the caudate nucleus and inferior occipital gyrus. In contrast, nasal breathing resulted in greater activity in 15 areas, including the cerebellum, insula, and inferior parietal gyrus - all known to play important roles in memory, attention, and information processing.2,3
Furthermore, the functional connections between different brain areas were significantly stronger during nasal compared to oral breathing. The left and right inferior parietal gyrus, key memory hubs, displayed increased connectivity to other regions only during nose breathing. This suggests that the neural communication and synchronization underlying memory is optimized by nasal respiration.
The researchers propose that the sensation of airflow through the nasal passages may provide important feedback signals to the brain that facilitate cognitive processing.
Conversely, the lack of this nasal stimulation during mouth breathing could explain the observed deficits in brain activation and connectivity.
While occasional mouth breathing, such as during a cold or allergies, is unlikely to cause lasting harm, the findings suggest that chronic oral respiration could potentially impair brain function over time. This is particularly concerning for the estimated 30-50% of adults4 who habitually breathe through their mouth, often due to nasal obstruction or simply out of habit.
In addition to the cognitive benefits, nasal breathing has been shown to offer numerous other advantages over oral respiration:
Filtration: The nose acts as a natural filter, trapping dust, allergens, and other irritants before they reach the lungs.5
Humidification: Nasal passages humidify inhaled air, protecting the delicate tissues of the airways and lungs from dryness.5
Nitric Oxide Production: Nasal breathing releases nitric oxide, a vasodilator that improves oxygen delivery throughout the body.6
Improved Lung Volume: Studies have found that nasal breathing results in greater lung volume and oxygen uptake compared to oral respiration during exercise.7
In light of this compelling evidence, experts recommend making a conscious effort to breathe through the nose as much as possible. For those who struggle with habitual mouth breathing, addressing any underlying causes such as nasal polyps or deviated septum can be beneficial, while noting that surgical approaches have significant risks and unintended, adverse effects that should be considered and balanced when weighed against the perceived benefits. Using mouth taping while sleeping, and breathing exercises, such as alternate nostril breathing from the yogic tradition, may also help train the body to default to nasal respiration.
The next time you're gearing up for a mentally taxing task, it may be worth paying attention to your breath. Closing your mouth and inhaling through your nose could provide the neural boost you need to excel. In the quest for better brain function, the nose seems to know best.