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17th Jun 2024

Popular mouthwash brand ‘could increase risk of bacteria linked to cancer,’ study claims

Charlie Herbert

‘Most people should not be using it’

Researchers have issued a cancer warning about a popular mouthwash brand, urging people not to use the product.

Scientists from Institute of Tropical Medicine in Antwerp, Belgium, found that using Listerine Cool Mint mouthwash increased the prevalence of two species of bacteria in people’s mouth.

The study discovered that those who used the mouthwash daily for three months had more Fusobacterium nucleatum and Streptococcus anginosus in their mouth.

These two species of bacteria have previously been linked with both esophageal and colorectal cancer.

One of those who worked on the study, Professor Chris Kenyon, told the Daily Telegraph that using the mouthwash daily “could increase their risk of cancer and various infections.”

He said: “Most people should not be using it and if they do use it, they should use the preparations without alcohol and limit the use to a couple of days.”

The research was looking at the impact of daily mouthwash use on STI risk among gay men. 

The 59 participants in the study used Listerine every day for three months followed by three months of placebo mouthwash or vice versa.

Listerine was the only mouthwash used in the study, but Professor Kenyon stressed that other alcohol-based mouthwashes would likely lead to similar levels of bacteria.

In a statement, Kenvue, which owns the Listerine brand, criticised the study.

They told the Telegraph: “Kenvue welcomes and encourages scientific advancements and exchanges to promote everyday health.

“Based on our initial review, the published trial lacks several important design controls and adequate rigour to make any conclusions about potential impact to human.”

In a response to the claims, Listerine told JOE: “Studies on the impact of LISTERINE® on oral health have been published in hundreds of peer-reviewed publications for more than a century, making it one of the most extensively tested oral mouthwash brands in the world. We continuously evaluate the latest science. There is no evidence that LISTERINE® causes cancer.”

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