What is Nitric Oxide?
Nitric Oxide (NO) is a signaling molecule that dilates blood vessels, improving blood flow and oxygen delivery. Your paranasal sinuses produce NO continuously; nasal breathing carries it into the lungs, where it is proposed to aid oxygen uptake. How large any such effect is in daily life is not established.
Key Functions
- •Vasodilation — widens blood vessels for better perfusion
- •Oxygen uptake — sinus NO reaching the lungs is proposed to aid oxygen uptake; the size of any effect in daily life is not established
- •Air conditioning — nasal passages filter, warm, and humidify air
- •Antimicrobial — NO has mild antimicrobial properties in the respiratory tract
Why does Nitric Oxide matter?
Nitric oxide matters because it is one of the body's key signals for relaxing blood vessels and regulating blood flow. Cells lining the blood vessels produce it, and it tells the surrounding smooth muscle to relax, which widens vessels and helps control blood pressure.
It also acts as a messenger in the nervous system and helps immune cells fight infection. Its discovery as a signaling molecule was recognized with a Nobel Prize in 1998, and it remains central to how doctors understand heart and vessel health.
What affects Nitric Oxide?
Several factors influence how much nitric oxide the body produces and how well it works. Regular physical activity increases production, partly because blood flowing along vessel walls stimulates the lining cells to release it.
Diet plays a role too. Nitrate-rich vegetables such as leafy greens and beets can be converted into nitric oxide through a pathway that involves mouth bacteria. Breathing through the nose also adds nitric oxide made in the sinuses to inhaled air. On the other hand, smoking, aging, high blood pressure, diabetes, and chronic inflammation are linked with reduced nitric oxide availability, part of what researchers call endothelial dysfunction.
In ONDA Life
The Breathwork CLI article suggests nasal breathing for low-to-moderate intensity under the name "Nitric Oxide Boost" — an image for the habit, not a promise of better oxygen uptake.