New research has looked to see how the popular mouthwash brand Listerine® impacts our oral microbiome – which is the community of bacteria in our mouth. Interestingly, there are some concerns from the findings, which suggests Listerine may not be entirely positive for our oral health.
Many of us use mouthwash as part of our daily oral hygiene routine. Some use it immediately after waking up, others do so straight after cleaning their teeth, and some do so after meals.
But while we may believe that mouthwash is having a positive impact on us, according to recent research, this isn’t entirely true.
Recent findings have suggested that a flavour of a popular brand of mouthwash – Listerine® – may actually have a negative impact on our oral health, which is concerning [1].
The findings are very interesting. However, the researchers have pointed out that there are certain caveats to their findings, which is important to remember when looking for conclusions from the study.
Background
The research involved the brand Listerine, whose well-known slogan is “Kills germs that cause bad breath.” Whilst there is no doubting the slogan is accurate, we can ask at what cost is this made possible?
Recent statistics show that approximately 200 million people in the United States use mouthwash [2]. Listerine compete in the mouthwash market with other household brands like Colgate and Oral-B.
Typical benefits of mouthwash include reducing plaque levels, freshening breath, improving symptoms of dry mouth, and strengthening the enamel through fluoride.
Another benefit is balancing the bacteria levels in the mouth – known as the oral microbiome. However, as recent research shows, this doesn’t necessarily happen.
The oral microbiome refers to the community of bacteria that live in the mouth. The composition of the oral microbiome is crucial, as a poorly balanced microbiome has been linked to a range of conditions, including tooth decay and some cancers [3].
The Research
The research was conducted by a team from the Institute of Tropical Medicine in Antwerp, Belgium. Their findings have been published in the Journal of Medical Microbiology [1].
The researchers were looking to see how mouthwash impacted the oral microbiome [1]. When the microbiome is in a healthy state, it boosts our oral health. But when problems arise, the microbiome can become a breeding ground for harmful bacteria.
To look into this, the researchers arranged a study which involved 59 participants. The participants were split into two groups. One group took the “Cool Mint” flavour of Listerine, whilst the other group took a placebo mouthwash [1].
The groups had a mouth swab after three months of daily use. Then, the groups swapped over for the next three months. Once again, samples were taken from mouth swabs at the end of the second period of three months [1].
Once the swabs had been taken, the researchers compared the swabs between the two groups using a range of analysis techniques. They were particularly interested to see if certain types of bacteria were present in the mouth.
The Results
The results were very interesting. The researchers found that two species of opportunistic bacteria were of a significantly higher volume in the saliva of those that had been using Listerine [1].
These two types of bacteria were Fusobacterium nucleatum and Streptococcus anginosus. These two bacteria have been linked to gum disease, esophageal and colorectal cancers in the past [1].
Arguably even worse – the researchers also found the level of a group of bacteria called Actinobacteria had decreased [1]. This group of bacteria are crucial contributors to the regulation of blood pressure.
Overall, the research showed that daily use of Listerine mouthwash can result in the oral microbiome being negatively affected. The abundance of the Fusobacterium nucleatum and Streptococcus anginosus bacteria makes a person more vulnerable to oral health problems.
Furthermore, there are also physical health considerations, with the lack of actinobacteria meaning blood pressure could worsen.
Author Comments
The findings are very interesting. In fairness to Listerine, the brand promise to freshen breath – which it certainly does. However, when analyzing the mouthwash in more detail, there are some concerning findings.
This is summarised by lead author Dr. Jolein Laumen, who has said the public use mouthwashes to “tackle bad breath or prevent periodontitis,” however, “they should be aware of the potential implications” [4].
However, the researchers have cautioned that we shouldn’t take substantial conclusions on their study. They have pointed out that the study didn’t take into account dietary habits, nor possible tobacco use, or other bacteria-causing behaviour [4].
Therefore, we can’t definitively say that Cool Mint mouthwash has a negative impact on our oral microbiome. However, there seems to be enough evidence to suggest there are potential issues.
Overall, we need to ensure we look after our oral health. Mouthwash can help in the majority of cases, but the main thing to do is to ensure you clean your teeth regularly and attend check-ups too!
Thinking points…
1) The above article shows us that even things that we think are good for our oral health aren’t necessarily healthy. In fact, you could be damaging your oral health without even realizing it. Therefore, it is very important to regularly see a dentist, so that they can check your oral health is strong. We recommend that you book an appointment now!
2) Do you use mouthwash as part of your oral hygiene routine? If so, it is worth checking the ingredients, and consulting your dentist over its use. If you don’t use mouthwash, then you could try and introduce it to your routine! It can be a great option for throughout the day to keep your breath fresh and mouth healthy. We recommend using mouthwash as part of your oral health routine.
What we offer at Savanna Dental
Savanna Dental is a dental clinic based in Calgary, Alberta, Canada. We provide our patients with a range of treatment options and advice, with the aim of improving oral health and boosting overall wellbeing!
We advise our patients to attend our Calgary-based dental clinic twice a year for a dental check-up. If any problems are detected, we have many treatments available. For instance, these include cavity fillings and root canals. To try and prevent problems, it is important to brush your teeth at least twice a day and floss regularly.
Here at Savanna Dental, we also have some cosmetic treatments available! These include dental implants, tooth whitening and Invisalign[TM]! Our patients find that these treatments have a positive impact on their appearance, confidence and self-esteem.
In addition, the fees of our services at our Calgary dental clinic Savanna Dental are set in line with the Alberta Dental Fee Guide.
We would love you to visit our Savanna Dental clinic in Calgary! You can find out more about us by visiting our website https://savannadentalclinic.ca/!
References
[1] Laumen, J. G. E., Van Dijck, C., Manoharan-Basil, S. S., de Block, T., Abdellati, S., Xavier, B. B., Malhotra-Kumar, S., & Kenyon, C. (2024). The effect of daily usage of Listerine Cool Mint mouthwash on the oropharyngeal microbiome: a substudy of the PReGo trial. Journal of Medical Microbiology. 73 (6). DOI: https://doi.org/10.1099/jmm.0.001830.
[2] Statista. (2024). U.S. population: Do you use mouthwash/ dental rinse?. Available: https://www.statista.com/statistics/276434/us-households-usage-of-mouthwash-and-dental-rinse/. Last accessed: 6th June 2024.
[3] Sharma, N., Bhatia, S., Sodhi, A. S., & Batra, N. (2018). Oral Microbiome and health. AIMS Microbiology. 4 (1): p42-66. DOI: https://doi.org/10.3934%2Fmicrobiol.2018.1.42.
[4] Microbiology Society. (2024). Commonly used alcohol-based mouthwash brand may disrupt the balance of your oral microbiome, scientists say. Available: https://medicalxpress.com/news/2024-06-commonly-alcohol-based-mouthwash-brand.html. Last accessed: 6th June 2024.