Dear Doctors: On Dr. Eve Glazier’s podcast, a dentist strongly recommended using a tongue scraper for oral health. Then I came across one of your columns, which warns against cleaning one’s tongue. I’m confused. Can someone clear this up?
Dear Reader: We understand how the information in those two discussions can be confusing. Dr. Glazier’s recent podcast featured a dentist in favor of cleaning the tongue for oral health. Our column explored emerging research that suggests the oral microbiome can play a role in regulating blood pressure. Together, the two discussions reflect the evolving understanding of the role that the oral microbiome plays in overall health. They also open the door to a more nuanced view of tongue cleaning and its effect on the oral microbiome.
The idea of an oral microbiome is fairly new. In the past, bacteria in the mouth were mostly associated with tooth decay and bad breath. However, the advent of rapid and affordable DNA sequencing has revealed a complex and often beneficial oral ecosystem. Between 700 and 1,200 species of microbes have been found to make their homes in the mouth. Many are harmless, and some are helpful. This includes bacteria that kick-start digestion. There are also bacteria that fight off harmful microbes, support the immune system and contribute to good health.
Then there are bacteria that live at the back of the tongue. This was the subject of the column you are referring to. These bacteria help convert a compound found in leafy greens, beets and similar foods, known as dietary nitrates. They convert the compound into a molecule called nitric oxide. This molecule is part of a metabolic process that relaxes the smooth muscle fibers in blood vessels. As a result, this supports healthy blood pressure.
One of the studies we wrote about found that using an antiseptic mouthwash twice a day weakened the oral microbiome. It disrupted the populations of the beneficial bacteria that help with blood pressure regulation. When study participants used the mouthwash, their blood pressure rose. When they stopped using it a week later, their blood pressure went back to normal. This led researchers to conclude that vigorous disruption of the oral microbiome may have unintended effects. And that takes us to tongue scraping.
Dr. Glazier’s podcast discussed the gentle, physical removal of the outermost layer of dead cells and debris that builds up on the surface of the tongue. This is different than the antiseptic mouthwash in the blood pressure study, which amounted to a broad antimicrobial assault. When practicing tongue scraping, it can be helpful to visualize the papillae. These are the tiny, cushionlike bumps that cover the surface of the tongue. The papillae house the oral microbiome. Light scraping would skim the surface and not broadly disrupt the ecosystem.
In our opinion, a daily gentle tongue scraping (with a tool designed for it) can be compatible with a healthy oral microbiome. If you’re unsure, as always, we recommend you check with your dentist.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
