Scientists warn that daily use of Listerine Cool Mint mouthwash 'could increase risk of cancer'

Experts at the Institute of Tropical Medicine in Antwerp, Belgium conducted research and found that the daily use of Listerine Cool Mint mouthwash led to two species of bacteria being more prevalent in the mouth after three months of daily use, with these bacteria both linked to oesophageal and colorectal cancer. The results found an abundance of Fusobacterium nucleatum and Streptococcus anginosus in the mouths of people who were using the alcohol-based mouthwash.

According to researchers, it may be the alcohol in the mouthwash that increase the prevalence of the bacteria. One expert warned that “most people should not be using” the popular bathroom item.

Professor Chris Kenyon told the Daily Telegraph: “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 study was conducted to investigate the impact of daily mouthwash use on the STI risk of gay men. 59 participants took part in the study and used Listerine Cool mint mouthwash for three months before using a milder mouthwash for another three months, with researchers comparing results form the two time periods.

Alongside the high presence of Fusobacterium nucleatum and Streptococcus anginosus, it was also found that there was a noted decrease in a strain called Actinobacteria. This bacteria is believed to regulate blood pressure and is considered to have anti-cancer properties.

While the results may cause concern for those who use the Listerine product daily, there were many noted limited of the study. For example, the participant’s dietary or smoking habits were not taken into account meaning that the use of the mouthwash cannot be singly attributed to the increased risk of cancer.

In a statement to the Telegraph, Kenvue, which owns the Listerine brand, said: “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 health.”