The immune system and the autonomic nervous system are deeply interconnected through the cholinergic anti-inflammatory pathway — a vagus nerve-mediated circuit that modulates immune cell activity. Chronic sympathetic activation (stress) suppresses immune surveillance while promoting chronic inflammation. Parasympathetic activation (via slow breathing) reverses this: it enhances immune surveillance while reducing harmful chronic inflammation.
Three pathways from breathing to immune health: (1) Nasal breathing produces nitric oxide, which has direct antimicrobial properties against bacteria and viruses in the upper airway. Nasal breathing is a first-line immune defense that mouth breathing bypasses entirely. (2) Vagal stimulation from slow breathing activates the cholinergic anti-inflammatory pathway, reducing the inflammatory cytokines (IL-6, TNF-alpha) that drive chronic disease. (3) Stress reduction preserves immune resources: cortisol suppresses lymphocyte production, so reducing cortisol through breathing exercises allows the immune system to function at full capacity.
The daily immune-support protocol: coherence breathing (5 minutes morning and evening) for general immune-supportive parasympathetic activation. Humming exhales (bhramari breathing) for 2-3 minutes to boost nasal nitric oxide production. These practices support — but do not replace — standard immune health behaviors: adequate sleep, nutrition, exercise, and vaccination. The evidence for breathing exercises directly preventing specific illnesses is still emerging; the evidence for breathing exercises creating the physiological conditions that support immune function is robust.