The Study
A stepwise reduction in plasma and salivary nitrite with increasing strengths of mouthwash following a dietary nitrate load.
This study showed that when healthy guys drank beet juice and then used different mouthwashes, some mouthwashes made the good chemicals in their blood go down and their blood pressure didn't drop as much. It's like testing which soap stops the magic from happening — but only in 12 guys, and only once.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
Your mouth has good bacteria that help turn veggies like beetroot into a substance that lowers blood pressure. Some mouthwashes kill these bacteria.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 546 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if you use strong antibacterial mouthwash daily, you might lose a natural way your body controls blood pressure, even if you eat healthy vegetables.
- 2Beetroot juice normally lowers blood pressure by 5–8 mmHg.
- 3Chlorhexidine mouthwash stopped this drop completely and cut nitrite levels by over 80%.
- 4Listerine didn't stop it.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nitric oxide : biology and chemistry
Year
2016
Authors
M. Woessner, J. Smoliga, B. Tarzia, T. Stabler, Mitch Van Bruggen, Jason D. Allen
Related Content
Claims (6)
Using Listerine antiseptic mouthwash does not lower nitrite levels in blood or saliva or reduce the drop in systolic blood pressure that occurs after consuming dietary nitrates.
Using chlorhexidine mouthwash reduces salivary nitrite by more than 80% and plasma nitrite by more than 70% compared to water, by blocking the conversion of dietary nitrate to nitrite, and it is the strongest known disruptor of this pathway among tested mouthwashes.
Dietary nitrate from foods like beetroot lowers blood pressure only if oral bacteria convert it to nitrite; using antibacterial mouthwash blocks this conversion and prevents the blood pressure reduction.
Using antibacterial mouthwashes with chlorhexidine or cetylpyridinium chloride after consuming beetroot juice reduces nitrite levels in blood and saliva by more than 60% and prevents the expected 5–8 mmHg drop in systolic blood pressure that normally follows nitrate intake.
Consuming 8.4 mmol of nitrate from beetroot juice leads to a 5–8 mmHg decrease in systolic blood pressure in healthy adults when oral bacteria convert nitrate to nitrite and nitric oxide.
The amount of nitrite in saliva cannot be used to determine how much nitric oxide is available in the bloodstream or the level of nitrite circulating in the blood.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.