Can a Mouth Rinse Help Lower Blood Pressure?
How a Nitrate-Rich, Antioxidant Mouthwash Supports Oral Bacteria and Heart Health
A New Look at Oral Care and Heart Health
Mouthwash is usually associated with fresh breath and cleaner teeth. But what if it could also support heart health? A recent study published in Scientific Reports suggests that the type of mouth rinse we use may influence blood pressure—through its effects on oral bacteria.
Researchers investigated whether a bioactive mouth rinse containing inorganic nitrate and antioxidants could support the body’s natural nitric oxide pathway and improve blood pressure, compared with a commonly used antibacterial mouth rinse containing chlorhexidine.
Why Oral Bacteria Matter More Than We Think
The mouth plays a surprising role in regulating blood pressure through what is known as the enterosalivary nitrate–nitrite–nitric oxide pathway. In simple terms:
Dietary nitrate (from vegetables like spinach and beetroot) enters the bloodstream.
About a quarter of it is secreted into saliva.
Beneficial bacteria on the tongue convert nitrate into nitrite.
Nitrite is later turned into nitric oxide, a molecule that helps relax blood vessels and lower blood pressure.
Antibacterial mouth rinses, while effective at killing harmful bacteria, may also wipe out these helpful nitrate-reducing microbes—potentially disrupting this protective pathway.
What Did the Researchers Do?
The study used male Wistar rats and compared two types of mouth rinses over one week:
A bioactive mouth rinse containing green tea, inorganic nitrate, vitamin C, and antioxidants
A standard chlorhexidine-based antibacterial rinse
The rinses were applied twice daily. Researchers then measured blood pressure, nitrate and nitrite levels in blood and saliva, antioxidant status, and changes in the oral microbiome.
Lower Blood Pressure with a Bioactive Rinse
The results were striking. Rats using the bioactive mouth rinse experienced significant reductions in blood pressure, while those using chlorhexidine did not.
Systolic blood pressure dropped by about 19 mmHg
Diastolic blood pressure decreased by about 18 mmHg
These improvements were closely linked to higher nitrate levels in blood and saliva—suggesting better support of the nitric oxide pathway.
Preserving “Good” Oral Bacteria
The bioactive rinse also helped maintain a healthier balance of oral microbes. Compared with the chlorhexidine group, rats using the bioactive rinse had higher levels of bacteria known to convert nitrate into nitrite, including Veillonella, Haemophilus, and Staphylococcus.
In contrast, the antibacterial rinse significantly reduced overall microbial diversity, which may weaken beneficial oral–systemic interactions.
Antioxidants Add an Extra Layer of Support
Although oxidative stress levels did not change dramatically over the short study period, the bioactive rinse helped preserve circulating antioxidant capacity, while antioxidant levels declined in the chlorhexidine group. This suggests the added antioxidants—green tea catechins and vitamin C—may help protect vascular health alongside nitrate.
What Does This Mean for Everyday Oral Care?
This study highlights an important message: not all mouth rinses are equal when it comes to overall health. While antibacterial rinses are useful in certain clinical situations, routine use may unintentionally interfere with beneficial oral bacteria that support blood pressure regulation.
A mouth rinse designed to work with the oral microbiome—rather than against it—could offer a simple, daily strategy to support both oral and cardiovascular health.
Looking Ahead
Because this study was conducted in animals and over a short period, further research in humans is needed. However, the findings open the door to a new way of thinking about oral hygiene—not just as dental care, but as part of whole-body health.
Reference
Senkus, K. E., Azrad, M., Bolland, A., Park, H.-A., Tice, J. R., Zhang, M., et al. (2025). Functional mouth rinse containing inorganic nitrate and antioxidants bolsters the enterosalivary pathway and lowers blood pressure in Wistar rats. Scientific Reports, 15, 26827.