4 Amazing Facts About Nitric Oxide & How It Improves Our Health!

Nitric oxide (NO) is a fundamental signaling molecule involved in numerous bodily functions including the regulation of blood flow through mechanisms such as vasodilation of the arteries (keeping them open and patent, reducing the risk of plaque), immune responses, and neural communication. The synthesis of nitric oxide, its regulation by various factors including diet and oral hygiene products like fluoride and mouthwash, and its dietary enhancement from sources such as cocoa, provides a comprehensive understanding of its pivotal role in human health.

1. Biosynthesis of Nitric Oxide in the Human Body

Nitric oxide is synthesised in the body from the amino acid L-arginine through the action of nitric oxide synthase (NOS) enzymes. These enzymes exist in three isoforms: endothelial (eNOS), neuronal (nNOS), and inducible (iNOS), each of which plays unique roles in different tissues (Moncada & Higgs, 1993). Endothelial NOS, for instance, is critical for regulating vascular tone and blood pressure by influencing the relaxation of smooth muscles in the blood vessels.

2. Alternative Pathways: Nitric Oxide in Saliva

An alternative pathway for NO production that has garnered significant interest involves its synthesis in the saliva through the reduction of dietary nitrates. Salivary glands absorb nitrates from the blood, which are then concentrated in the saliva. Oral bacteria convert these nitrates to nitrites, which are transformed into nitric oxide when they interact with the acidic environment of the stomach (Lundberg, Weitzberg, & Gladwin, 2008). This pathway underscores the interaction between diet, bacterial flora, and physiological processes.

3. Influence of Fluoride and Mouthwash

The integrity of oral bacteria is crucial for the nitrate-nitrite-NO conversion. This delicate balance can be disrupted by agents that alter the bacterial population in the mouth. For instance, while fluoride commonly used in dental care does not significantly impact the bacteria involved in nitrite production (Li, Helderman, & Whelton, 2005), antibacterial mouthwashes may inhibit their activity. A study by Govoni et al. (2008) demonstrated that mouthwash containing antibacterial agents could decrease oral nitrite levels and thus potentially reduce gastric nitric oxide synthesis, impacting cardiovascular health.

4. Dietary Sources to Promote Nitric Oxide Production

To optimize nitric oxide levels, certain dietary strategies can be particularly effective:

High-Nitrate Vegetables: Vegetables like spinach, lettuce, and beets are high in nitrates, which are essential precursors for NO synthesis via the salivary pathway. Webb et al. (2008) found that beetroot juice supplementation could lower blood pressure in healthy volunteers, an effect attributed to increased nitric oxide availability.

L-Arginine Sources: Foods rich in L-arginine such as turkey, pork loin, and pumpkin seeds directly supply the substrate for enzymatic production of nitric oxide by NOS. Morris (2004) highlighted that diets high in L-arginine could improve endothelial function and blood flow.

Cocoa and Dark Chocolate: Cocoa contains flavonoids that enhance nitric oxide synthesis in the endothelium by increasing the activity of eNOS. A study by Fisher et al. (2003) demonstrated that the consumption of flavanol-rich cocoa led to heightened endothelial function and increased NO levels, which in turn lowered blood pressure and improved vascular health.

Conclusion

Nitric oxide plays a multifaceted role in maintaining and regulating numerous physiological systems within the human body. From its synthesis in various body sites to its unique production mechanism in saliva and the influences of external factors such as diet and oral hygiene products, NO’s impact is profound. Understanding these pathways and interactions can aid in the strategic enhancement of NO levels through dietary choices and lifestyle changes, fostering better overall health outcomes.

As research continues to advance, integrating comprehensive dietary strategies, including the regular consumption of nitrate-rich vegetables, L-arginine-rich foods, and flavanol-containing cocoa, alongside judicious use of oral health products, will be crucial in maximising the health benefits of nitric oxide for cardiovascular and general health.

References

Alderton, W. K., Cooper, C. E., & Knowles, R. G. (2001). Nitric oxide synthases: Structure, function and inhibition. Biochemical Journal, 357(3), 593-615.

Fisher, N. D., Hughes, M., Gerhard-Herman, M., & Hollenberg, N. K. (2003). Flavanol-rich cocoa induces nitric-oxide-dependent vasodilation in healthy humans. Journal of Hypertension, 21(12), 2281-2286.

Govoni, M., Jansson, E. A., Weitzberg, E., & Lundberg, J. O. (2008). The increase in plasma nitrite after a dietary nitrate load is markedly attenuated by an antibacterial mouthwash. Nitric Oxide, 19(4), 333-337.

Li, H., Helderman, H., & Whelton, H. (2005). Effect of fluoride on nitric oxide production in saliva. Journal of Dental Research, 84(10), 919-923.

Lundberg, J. O., Weitzberg, E., & Gladwin, M. T. (2008). The nitrate-nitrite-nitric oxide pathway in physiology and therapeutics. Nature Reviews Drug Discovery, 7(2), 156-167.

Moncada, S., & Higgs, A. (1993). The L-arginine-nitric oxide pathway. The New England Journal of Medicine, 329(27), 2002-2012.

Morris, C. R. (2004). Mechanisms of disease: arginine metabolism in vascular biology and disease. Nature Clinical Practice Cardiovascular Medicine, 1(1), 42-49.

Webb, A. J., Patel, N., Loukogeorgakis, S., Okorie, M., Aboud, Z., Misra, S., Rashid, R., Miall, P., Deanfield, J., Benjamin, N., MacAllister, R., Hobbs, A. J., & Ahluwalia, A. (2008). Acute blood pressure lowering, vasoprotective, and antiplatelet properties of dietary nitrate via bioconversion to nitrite. Hypertension, 51(3), 784-790.