Your mouthwash may raise your risk of diabetes

Here’s a new twist on your daily oral care routine – using mouthwash daily may be putting you at an increased risk of diabetes, especially people already at a higher risk for the disease, according to a new study from researchers at Harvard.  Surprisingly, this study warns that taking a swill of mouthwash to freshen breath more than once a day kills not only harmful bacteria in the mouth but also helpful bacteria that may protect the body from obesity and diabetes.

Study on mouthwash and diabetes

Published in the journal Nitric Oxide, this research estimates that someone who uses mouthwash twice a day could be increasing their risk of developing type 2 diabetes by as much as 55 percent.  An eye-opening finding was that almost a third of people who report using mouthwash more than twice a day had a higher incidence of being diagnosed with the disease after a three-year follow-up. 

The study, which was part of the San Juan Overweight Longitudinal Study in Puerto Rico, evaluated 1,206 overweight people between the ages of 40-65 without diabetes or any known history of coronary artery disease. 

Among the participants, 43 percent used mouthwash at least once a day while 22 percent used it at least twice a day. 

Each of the subgroups was already at a higher risk for developing prediabetes or diabetes.  Adjustments were made for education, income, sleep breathing disorders, factors related to oral hygiene, fasting glucose, diet, smoking, and obesity.

Why would mouthwash increase risk of diabetes?

The reasoning behind why what most of us assume is a beneficial practice in our mouth care, is that the antibacterial ingredients in mouthwash are not selective at what they destroy – they kill both bad oral bacteria but also good types of oral bacteria. 

Bad bacteria in the mouth contribute to the development of plaque and bad breath.  The more beneficial or good bacteria, however, can protect against diabetes and obesity since they produce a chemical called nitric oxide that helps to regulate insulin levels. 

Nitric oxide is critical for regulating metabolism or the rate at which we burn calories along with balancing energy and keeping blood sugar levels in check. 

Best advice on mouthwash use

Since this study only showed an association between frequent use of mouthwash and development of diabetes, it is not a cause and effect relationship.

For now, until more studies are conducted or data collected, limiting the use of mouthwash to once a day may be advisable.  This advice is especially true for anyone who is overweight, has a strong family history of diabetes or has an elevated hemoglobin A1C.