Could all the benefits of using mouthwash—fighting cavities and persistent bad breath—get worse by using mouthwash? Some dentists say they do more harm than good.
There are also correlations between certain kinds of mouthwash and more serious health issues, including high blood pressure, heart disease, and oral diseases.
The Evolution of Mouthwash
The origins of using mouthwash can be traced back to around 2700 B.C., when it was used in traditional Chinese medicine (TCM) for treating gum diseases.
“Li Ji,” translated as “The Book of Rites” (written around 221 B.C.) from the early Qin Dynasty, stated that rinsing with salt water was used as a tooth-cleaning method at the time, according to a 2023 study published in the Journal of Ethnopharmacology.
However, our modern-day mouthwashes are far from a simple salt water rinse. In fact, they weren’t even intended to be mouthwashes at all.
The mouthwash Listerine, acquired by Johnson & Johnson from Pfizer in 2006, was originally developed as a surgical antiseptic in 1865 and named after Joseph Lister, who performed the first antiseptic surgery.
According to the book “Health & Drugs, Disease, Prescription & Medication” by Nicolae Sfetcu, after its use as an antiseptic for surgery, it was distilled and sold as a floor cleaner and a cure for gonorrhea. In the 1920’s, it was rebranded and sold as a cure for “chronic halitosis” (bad breath) and was the first over-the-counter mouthwash to receive the American Dental Association’s prestigious seal of approval.
Dr. Jack Kall, a practicing biological dentist with 46 years of experience and the executive chair of the board of directors of the International Academy of Oral Medicine and Toxicology, said he typically does not recommend using conventional mouthwash regularly.
“I would reserve their use for very limited times, such as if you’re going on a job interview, or you have something happening close up to where you want to be covering up garlic breath,” Kall told The Epoch Times.
Problems Revealed by Research
Kall points to research showing that overuse of antibacterial products, including mouthwashes, can have negative effects on different aspects of our health.
Imbalance in the Oral Microbiome
Regular use of conventional mouthwash can disrupt the oral microbiome and knock it out of balance, a state known as dysbiosis. Antibacterial products not only kill harmful bacteria but also the good bacteria needed for many vital functions, including fighting off bacterial and viral infections.
Several studies reveal connections between diseases, viruses, and alterations in the oral microbiome. For instance, when imbalances occur in the oral microbiome, they can prompt gut microbes to generate carcinogenic toxins, triggering gut inflammation and metabolic complications.
High Blood Pressure
Kall said that the antiseptic ingredients in conventional mouthwash can also interfere with the nitrate–nitrite–nitric oxide (NO) pathway at the back of the tongue.
This pathway is important in the oral microbiome because dietary nitrates are converted to NO.
NO is one of the most important signaling molecules in our bodies and plays a crucial role in regulating many physiological functions, such as blood flow by promoting vasodilation, immune response, and microbial homeostasis.
A study published in Frontiers in Cellular and Infection Microbiology in 2019 warns that the use of “oral antiseptics resulted in increases in systolic blood pressure.”
The study looked specifically at chlorhexidine, an antiseptic used in mouthwash.
“Twice-daily chlorhexidine usage was associated with a significant increase in systolic blood pressure after 1 week of use and recovery from use resulted in an enrichment in nitrate-reducing bacteria on the tongue,” the study authors wrote.
Another study published in the American Journal of Hypertension had similar findings. It concluded, “Results of this study suggest that use of antibacterial mouthwash by treated hypertensive individuals could have a detrimental effect on blood pressure. Of concern is the widespread use of mouthwash in the general population.”
Dry Mouth, Cavities, and Fungal Infections
Many mouthwash products contain alcohol, which has a drying effect, and that can be problematic over time, warned Kall. That’s because saliva has several important roles that are compromised when the mouth is dry.
Saliva contains minerals like calcium and phosphate that help keep teeth strong and fight tooth decay, according to the National Institute of Dental and Craniofacial Research.
Saliva also helps keep invading germs in check, so reduced saliva can contribute to fungal infections and bad breath.
Weak Composite Fillings
Kall said the harsh ingredients in many mainstream mouthwashes has a softening effect on the composite filling materials (the tooth-colored filling materials).
“Alcohol can be problematic for composites and cause a quicker breakdown, shortening the amount of time that those composites will hold up,” Kall said.
A study published in the Journal of Clinical and Experimental Dentistry stated “The use of mouthwashes triggered changes on the structure of both dental materials: composite resin and resin modified glass ionomer.”
Chemical Soup
Aside from alcohol, Kall said chlorhexidine is another mouthwash ingredient to avoid.
Chlorhexidine is used as a surgical scrub and diluted down and flavored for use as a mouthwash.
Some oral surgeons will recommend it after surgery to reduce the risk of infection, Kall said, but “you definitely don’t want to be using that for very long.” Aside from disrupting the oral microbiome, it can also stain teeth with fillings.
“Unfortunately, when you look at the inactive ingredients [in mouthwash], it’s a chemical alphabet soup. A lot of times there are various dyes or flavoring agents in them. Why expose yourself to these chemicals?” he said.
They can be problematic, he said, particularly with chronic long-term consumption. Even if you’re not swallowing the mouthwash intentionally, some still end up in your stomach.
“That gets down into your gut, and now your body has to deal with these irritating chemicals that can possibly cause leaky gut issues or chemical sensitivities,” Kall said.
Harmful ingredients to look out for include alcohol, chlorine dioxide, chlorhexidine, cocamidopropyl betaine, parabens, poloxamer 407, formaldehyde, and saccharin.
Alternative Solutions
There are many effective homemade mouthwashes with antiseptic properties that support gum tissue.
Kall suggests the following alternatives:
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Saltwater or Hydrogen Peroxide: Both can have antiseptic effects.
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Baking Soda: Is a mild abrasive, which can help remove plaque, and has natural whitening properties.
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Herbal Products and Essential Oils: Herbal extracts such as from Papua-mace, and oils such as peppermint, tea tree, clove bud, cinnamon bark, eucalyptus, and thyme have been shown to kill germs and heal gum tissue.
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Oil pulling: Oil pulling comes from Ayurveda, the ancient holistic system of medicine that originated in India 3,000to 5,000 years ago. It involves swishing oil, such as sesame or coconut oil, in the mouth for three to five minutes.
According to a review in the Journal of Ayurveda and Integrative Medicine, oil pulling is mentioned in the Ayurvedic text Charaka Samhita and “claimed to cure about 30 systemic diseases ranging from headache, migraine to diabetes and asthma.” It was also used to prevent tooth decay, bad breath, bleeding gums, throat dryness, cracked lips, and strengthen the teeth, gums, and jaw.
Oral probiotics: A randomized clinical trial published in the Journal of Medical Microbiology in 2013 found that a specific strain of good bacteria, called Streptococcus salivarius strain M18, has been shown to improve dental health and reduce cavities by recolonizing the mouth with good bacteria while crowding out the bad bacteria.
Although herbal-based products and alternatives are the healthier choice,some herbs are very effective antimicrobial agents and can be overdone, similar to the chemical options, Kall said.
To the Root
As a biological dentist, Kall approaches dentistry holistically, using the least-toxic treatment options.
There are several factors that cause dental issues and bad breath. Some of the main ones are dysregulation of the body, oxidative stress, and dry mouth, Kall said.
For example, problematic or bad bacteria thrive when there’s too much free iron in our tissues. When that happens, the small amount of bad bacteria, which is okay normally, starts proliferating. An overabundance of free iron can occur when our bodies have inadequate levels of copper, magnesium, and retinol.
We can minimize oxidative stress through diet and lifestyle choices, such as avoiding sugar, chemicals, pesticides, heavy metals, and food additives, and adding nervous system-regulating activities such as grounding (touching the earth with bare feet), exercise, meditation, and acupuncture, Kall said.
Dry mouth can be caused by drying agents such as alcohol, but can also be exacerbated by mouth breathing. There are remineralizing sprays that can help, as well as nighttime devices that discourage mouth breathing, Kall said.
The Epoch Times reached out to Johnson & Johnson for comment about Listerine mouthwashes, but did not receive a response.
Correction: A previous version of this article misstated the name of the International Academy of Oral Medicine & Toxicology. The Epoch Times regrets the error.