For generations, mouthwash has been a cornerstone of many oral hygiene routines, marketed as a swift and easy way to fight bad breath and promote a clean mouth. However, a growing body of research is challenging that conventional wisdom, with dental professionals now warning that daily use of some mouthwashes may actually be detrimental to oral and overall health. New studies indicate thes products can disrupt the delicate balance of the oral microbiome, potentially increasing risks ranging from gum disease to elevated blood pressure, prompting some experts to question if it’s time to rethink this common practice-particularly as global mouthwash sales exceeded $6.5 billion in 2023.
A seemingly harmless bottle in the bathroom could be doing more harm than good, according to dental professionals. Mouthwashes, often used to protect teeth, may disrupt the natural balance of the oral microbiome and even impact blood pressure.
Common Routine, Problematic Habit
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For many, oral hygiene is a three-step process: brushing, flossing, and rinsing with mouthwash. However, dentists are increasingly questioning the value of that final step. Kristin Arpo, a dentist, suggests that many over-the-counter mouthwashes act as powerful disinfectants, potentially causing more issues than they solve, according to a recent interview with FOCUS online. The global implications of this finding are significant, as mouthwash is a staple in many households worldwide.
While marketed for their antibacterial protection, the reality is more complex. The mouth isn’t a sterile environment – and shouldn’t be.
The Mouth’s Own Microbial World
The oral cavity is the second largest microbial ecosystem in the human body, after the gut. It’s home to thousands of species of microorganisms. While some can cause disease, like periodontitis, when they overgrow, many bacteria play a protective role.
Arpo explains that this delicate balance is the core of the problem. Many mouthwashes eliminate beneficial bacteria, allowing harmful ones to survive and proliferate. This can lead to worsening gum and tooth health.
Study Shows Increase in Risky Bacteria
Research from Belgium and South Africa highlighted these risks, tracking the effects of Listerine Cool Mint antibacterial mouthwash. Participants used the mouthwash for three months, while a control group rinsed with a placebo solution.
The results were surprising. Those using the antibacterial mouthwash experienced an increase in two bacterial strains:
Fusobacterium nucleatum, linked to periodontitis
Streptococcus anginosus, which can contribute to tooth decay, tonsillitis, abscesses, and bad breath.
Researchers also found that both strains have been associated with a higher risk of esophageal and colorectal cancer, leading them to recommend avoiding alcohol-based and antiseptic mouthwashes for daily use.
Impact Extends to Blood Pressure
The negative effects may not be limited to the mouth. Arpo points out that certain ingredients in mouthwashes, particularly chlorhexidine, can interfere with blood pressure regulation and contribute to antibiotic resistance with prolonged use.
An Australian study found that participants using chlorhexidine mouthwash had an average increase of 2.3 mmHg (millimeters of mercury) in blood pressure after just three days, compared to those rinsing with water alone.
This is due to chlorhexidine’s destruction of bacteria that convert nitrates into substances essential for blood vessel elasticity. Without these bacteria, hypertension can develop over time.
A similar American study, following 540 people who used mouthwash at least twice daily for three years, showed nearly a doubled risk of developing high blood pressure. This risk wasn’t limited to chlorhexidine-containing products; some formulations relied on essential oils.
When Mouthwash Can Be Beneficial
Dentists emphasize that mouthwashes aren’t always detrimental. They can be helpful short-term after surgical procedures or implant placement – but always under a professional’s guidance.
The issue lies primarily with their daily and uncontrolled use, often simply for a feeling of freshness.
How to Care for Your Mouth Without Mouthwash
Arpo stresses that a proper brushing technique should provide a feeling of cleanliness, rather than relying on chemical solutions.
Her three key recommendations:
- Use a high-quality sonic toothbrush – frequency is more important than brand.
- Clean between teeth at least every other day, ideally before brushing.
- And a simple, clear message: “Throw away your mouthwash.”
