Does your fight to get rid of bad breath also come with unexpected health consequences? Some researchers believe you should reach for that bottle of amber, blue or green liquid on your sink with caution.
People who used mouthwash twice or more daily had a “significantly” higher risk of developing pre-diabetes and diabetes than those who swished it less frequently, a study recently published in the journal Nitric Oxide found. The authors believe it’s the first paper to look at whether mouthwash use is a risk factor for the disease.
But a diabetes expert was skeptical. Dr. William T. Cefalu, chief scientific, medical and mission officer for the American Diabetes Association, called the study "interesting," but said there seemed to be inconsistencies in the data and noted the proposed relationship between mouthwash use and diabetes risk did "not seem plausible."
Why would mouthwash possibly play a role?
But other microbes are potentially beneficial, said lead author Kaumudi Joshipura, director of the Center for Clinical Research and Health Promotion at the University of Puerto Rico and adjunct professor of epidemiology at the Harvard T. H. Chan School of Public Health.
"Mouthwash is often advertised for killing germs, and killing most or all oral bacteria is not necessarily a good thing," Joshipura told TODAY.
Some of the microbes in your mouth help your body form nitric oxide, a chemical linked to blood flow that also plays an important role in regulating endothelial function, blood pressure and insulin sensitivity — all of which are related to diabetes, Joshipura noted.
When you use mouthwash that contains antibacterial ingredients, it gets rid of a “broad spectrum” of bugs, including the potentially helpful ones that may play a role in your body’s processes, the researchers note.
For the paper, they followed 945 overweight or obese Puerto Ricans who didn’t have diabetes at the start of the study. They kept track of their over-the-counter mouthwash habits, but didn’t focus on specific brands.
After three years, 30 percent of the people who used mouthwash twice or more a day progressed to pre-diabetes or diabetes, compared to 20 percent of those who used the rinses less frequently. Ultimately, the very frequent mouthwash users had a 55 percent higher risk of developing one of the conditions than the less frequent users, the study notes. The impact stayed the same when the researchers controlled for age, sex, smoking, physical activity, alcohol consumption and other factors.
The researchers believe the findings would be similar for people of normal weight.
What you need to consider:
The study authors caution "the indiscriminate routine use" of antibacterial mouthwash may cause more harm than good.
"Since no studies have demonstrated the safety of long-term twice daily use of mouthwash, people should be cautious in using mouthwash," Joshipura said, adding her advice applies to both healthy people as well as those at high risk for diabetes.
But Cefalu said the study is not conclusive enough that people should alter their use of mouthwash. In fact, diabetes patients are at special risk for periodontal disease.
"The most important diabetes risk factors that people can take action on are lifestyle, including nutrition and physical activity, as well as good oral hygiene," Cefalu said.
Using mouthwash does not take the place of optimal brushing and flossing, but therapeutic mouthwashes can help control or reduce gingivitis, plaque and tooth decay, according to the American Dental Association. Some mouthwash manufacturers say their formula is actually beneficial to the oral microbiome.