CDA Essentials 2018 • Volume 5 • Issue 2

26 | 2018 | Issue 2 N ews and E vents Previous short-term clinical trials have shown a correlation between frequent use of chlorhexidine mouthwash and the decrease of nitric oxide (NO) bioavailability and the increase of blood pressure. Based on these previous findings, Dr. Joshipura and her co-authors decided to conduct the first long- term evaluation of mouthwash use and its incidence on pre-diabetes/diabetes. The San Juan Overweight Adults Longitudinal Study (SOALS) examined over 1,000 overweight and obese individuals from Puerto Rico, aged from 40 to 65 years, over a three-year period. All participants had to undergo a baseline examination, which consisted of several blood tests and questionnaires, the latter particularly to assess frequency of mouthwash use. The data on the participants’ oral health routine was self-reported. After three years, the participants had a follow-up examination. Individuals who used mouthwash more than twice a day showed an increased risk ratio of 1.5 of developing pre-diabetes/diabetes after three years, compared to less frequent mouthwash users. The study authors argue that the antibacterial ingredients contained in mouthwash may have a detrimental impact on bacteria present in our mouth that are critical for NO metabolism, which affects metabolic health, including obesity, insulin resistance and diabetes. “It is a 50% increased risk, compared to people who use mouthwash less frequently, or people who do not use mouthwash at all,” reports Dr. Joshipura. This increased risk is hypothetically due to direct effects of the antibacterial ingredients present in mouthwash on the oral microbiome, specifically on NO bioavailability. The associations were independent from well-known risk factors for diabetes, such as smoking, BMI or physical exercise. Dr. Joshipura admits that although the study results are interesting, they should be interpreted with caution. Further research needs to be conducted to analyze the NO production pathways and evaluate the direct effects of antibacterial mouthwash on them. Additional studies are also needed to corroborate these findings in other populations, such as normal weight individuals or in more ethnically diverse populations. Dr. William Cefalu, chief scientific and medical officer of the American Diabetes Association, remains skeptical about a hypothetical association between frequent use of mouthwash and an increased risk of developing diabetes. In a public statement, he claims that the association “does not seem plausible,” because the results vary greatly depending on the frequency of mouthwash use. He also wished the study would have addressed the confirmed associations between periodontal disease and diabetes. The individuals using mouthwash more than twice a day may have had underlying periodontal conditions, which could account for the increased risk of pre-diabetes/diabetes. Mouthwash is an important component of many people's oral health routine, and this study does not recommend to stop using it. Dr. Joshipura believes that people should start thinking of why they are using mouthwash. “There is prescription mouthwash, taken for a short term, for a specific pathology or condition, and then there is the cosmetic concept of ‘it’s just a good thing to add to the routine’. Given that there may be potential systemic risks, we need to think about the systemic impact of the balance of the good and the bad bacteria,” she says. “In recent years, there has been a growing awareness that we need to focus on the dysbiosis of the bacteria and not just on eliminating the entire dental biofilm.” a “There has been a growing awareness that we need to focus on the dysbiosis of the bacteria and not just on eliminating the entire dental biofilm.” Reference 1. Joshipura KJ, Muñoz-Torres FJ, Morou-Bermudez E, Patel RP. Over-the-counter mouthwash use and risk of pre-diabetes/diabetes. Nitric Oxide . 2017 Dec 1;71:14-20. To hear an interview with Dr. Joshipura on this study, visit oasisdiscussions.ca /2017/12/18/mw