A New Study Found that Mouthwash Kills Mouth Bacteria but may Increase Risk for Diabetes

A new study has found that using mouthwash frequently is linked with a higher risk for developing type 2 diabetes in people who have pre-existing conditions that put them at an increased likelihood of developing the metabolic disease.

Increased Risk For Diabetes In Frequent Users Of Mouthwash

In a new study published in the December issue of the journal Nitric Oxide, researchers looked at the data of more than 900 overweight or obese individuals who were part of the San Juan Overweight Adults Longitudinal Study in Puerto Rico.

Study researcher Kaumudi Joshipura, from Harvard School of Public Health, and colleagues found that the participants who used mouthwash at least twice a day had a 55 percent higher risk of developing prediabetes or diabetes over the three-year follow-up period, compared with those who used mouthwash less frequently. Of those who used mouthwash at least twice a day, 30 percent developed either of diabetes or prediabetes.

Researchers said that the association continues to emerge even after taking into account other factors that may contribute to the development of diabetes.

“The effect estimates were similar after adding income, education, oral hygiene, oral conditions, sleep breathing disorders, diet (processed meat, fruit, and vegetable intake), medications, HOMA-IR, fasting glucose, 2hr post load glucose or CRP to the multivariate models,” the researchers wrote in their study.

Mouthwash

Most mouthwashes contain bacteria-killing solutions that are meant to stop the growth of bacteria in the mouth that cause plaque and bad breath. In a 2016 study, researchers found evidence that the popular mouthwash Listerine can control gonorrhea bacteria in people’s mouth and throat.

While the antibacterial fluid is used to kill harmful oral bacteria, researchers of the new study said that it could also be indiscriminately killing the beneficial strains of microbes that provide protection against obesity and diabetes, as well as those that help the body produce nitric oxide.

Nitric oxide helps regulate the insulin levels of the body. It plays an important role in regulating metabolism, balancing energy, and keeping the body’s sugar levels in check.

“Most of these antibacterial ingredients in mouthwash are not selective,” Joshipura said. “In other words, they do not target specific oral bacteria – instead, these ingredients can act on a broad range of bacteria.”

Researchers also said that eliminating the helpful bacteria in the mouth may allow potentially harmful bacteria to thrive and thus recommend limiting the use of mouthwash to just once a day.