Nasal Breathing: A Breath of Fresh Air for Cardiovascular Wellness – Insights from New Research

The leading cause of death in the United States is cardiovascular disease, and the risk of cardiovascular issues can be predicted by factors such as blood pressure, heart rate variability, blood pressure variability, and cardiac vagal baroreflex sensitivity. The interplay between the cardiovascular and respiratory systems is highlighted, with a particular emphasis on how respiration affects key prognostic cardiovascular variables.

This study explores the impact of nasal breathing compared to oral breathing on cardiovascular health in young adults. Nasal breathing is associated with humidification, warming, and filtration of inhaled air, potentially leading to bronchodilation and improved breathing efficiency. While past research has shown nasal breathing to have positive effects on resting metabolic demands, its influence on cardiovascular markers is not well-understood.

The primary hypothesis is that nasal breathing, as opposed to oral breathing, will result in decreased blood pressure, improved heart rate variability, reduced blood pressure variability, and increased cardiac vagal baroreflex sensitivity at rest. The study aims to contribute to the understanding of how breathing patterns influence prognostic cardiovascular variables, aligning with the broader interest in the impact of breathing pace and training on cardiovascular health.

The secondary hypothesis focuses on the effects of nasal breathing during submaximal exercise. The expectation is that nasal breathing, by attenuating the ventilatory response and metabolic demands, will lead to reduced blood pressure responses, improved heart rate variability, and decreased blood pressure variability during exercise. This aspect is particularly relevant due to the association between elevated exercise blood pressure and the risk of developing hypertension and cardiovascular disease.

Findings

The study findings are summarized, focusing on the impact of nasal vs. oral breathing on physiological and subjective variables at rest and during exercise. At rest, nasal breathing is associated with lower mean and diastolic blood pressure, improved heart rate variability metrics, reduced LF/HF ratio, and lower ratings of perceived exertion (RPE) and breathlessness (RPB). However, it increased systolic blood pressure average real variability. During submaximal exercise, differences between nasal and oral breathing were observed for RPB, suggesting a modest effect on reducing breathlessness during acute exercise.

The discussion delves into the potential clinical significance of these findings, particularly the reduction in diastolic blood pressure during nasal breathing at rest. The study suggests a greater parasympathetic to sympathetic dominance during nasal breathing, indicated by changes in frequency-domain metrics of heart rate variability. Although nasal breathing did not significantly affect beat-to-beat blood pressure variability, there is speculation about potential connections between respiratory variables and blood pressure changes, emphasizing the need for further investigation.

The study notes that the impact of nasal breathing on cardiovascular variables may have implications for various populations and suggests avenues for future research, including examining nasal breathing's effects on blood pressure over longer durations, both at rest and during activities like exercise. The discussion also touches on the potential benefits of interventions like mouth-taping overnight, emphasizing the importance of considering nasal breathing in the context of broader health outcomes.

In summary, the study highlights the potential benefits of nasal breathing, with improvements in various cardiovascular and subjective measures at rest. While the effects during exercise are more modest, the findings contribute to understanding the nuanced relationship between respiratory patterns and cardiovascular health.

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references

Watso, Joseph C., et al. “Acute Nasal Breathing Lowers Diastolic Blood Pressure and Increases Parasympathetic Contributions to Heart Rate Variability in Young Adults.” American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, vol. 325, no. 6, 1 Dec. 2023, pp. R797–R808, pubmed.ncbi.nlm.nih.gov/37867476/, https://doi.org/10.1152/ajpregu.00148.2023.