A mouthwash of mouthwash is part of many people’s daily dental routine, whether to freshen breath or prevent cavities.
But although a quarter of the population uses mouthwash, new evidence suggests it may do more harm than good.
Research has found that antiseptic mouthwash is linked to an increased risk of high blood pressure and other medical conditions, and its antibacterial properties are believed to be the cause.
So what’s going on and should you use it?
It is well known that the use of antibiotics can disrupt the gut microbiome – the colony of microbes, including bacteria, that play an important role in our digestive and immune systems by eliminating good and bad bacteria.
Research has found that antiseptic mouthwash is linked to an increased risk of high blood pressure and other medical conditions.
Now the focus is on the oral microbiome (the diverse colony of microbes in our mouths) and specifically how using mouthwash could eliminate some of the good bacteria that help protect our bodies against conditions such as heart disease and diabetes. type 2.
“The mouth is full of hundreds of species of bacteria, and while some cause plaque and cavities, others are actually very good for your health and responsible for quite complex processes in the body,” says Dr. Zoe Brookes, Associate Professor of Education. and Dental Research at the University of Plymouth.
«For example, there are bacteria that live on the tongue and convert nitrates from the foods we eat into nitrites which are then converted to nitric oxide in the intestine; Nitric oxide effectively tells our blood vessels to relax, keeping our blood pressure nice and low. ‘ explains Dr. Brookes, who led a 2020 study on the effects of mouthwash on the oral microbiome.
“Several studies have found that using mouthwashes, especially brands containing the antiseptic chlorhexidine, can cause an increase in blood pressure, especially in people who already have elevated levels.”
A 2019 study from the University of Puerto Rico found that people who used mouthwash twice a day or more had a higher risk of high blood pressure compared to less frequent users.
And a 2017 study, conducted by the same Puerto Rico-based research group, found that overweight people who used over-the-counter mouthwash at least twice a day had a 50 percent increased risk of developing type 2 diabetes. over a three-year period compared to non-users.
The researchers said that killing these key oral bacteria reduces the body’s ability to produce nitric acid, which in turn prevents the effective breakdown of blood sugar, causing dangerous blood sugar spikes that can eventually lead to diabetes. time.
Dr Brookes said: “Keeping our teeth and gums healthy is more important than ever, especially when so many people can’t even go to an NHS dentist right now.”
And that’s not the only potentially harmful side effect of mouthwash. A 2020 study published in the Journal Intensive Care Medicine found that antiseptic mouthwash used by patients who have been hospitalized may increase their risk of death from sepsis; This is a life-threatening condition that occurs when the body’s immune system overreacts to an infection, leading to organ failure and sometimes death.
Scientists aren’t sure what’s behind the increased risk, but they suggest that killing the oral bacteria responsible for nitric acid production prevents the body from absorbing enough of this compound, which plays a key role in healthy circulation. and we know that circulation is one of them. of the body’s systems that shut down in sepsis.
Against this we must weigh the benefits of mouthwash.
“Of course, there is also compelling evidence that when patients use mouthwashes containing the antiseptic chlorhexidine (along with brushing their teeth) they reduce the plaque that causes cavities and early gum disease,” says Dr. Brookes. .
Several studies have found that using mouthwashes, especially brands containing the antiseptic chlorhexidine, can cause an increase in blood pressure.
“But it’s a double-edged sword, because chlorhexidine is so powerful that it kills many different species of bacteria, including the good ones. And by unbalancing our oral microbiome in this way we can indirectly affect not only the health of our heart, but we also increase the risk of succumbing to other problems such as sepsis and also contribute to the broader problem of antibiotic resistance,” Add.
So should we pour our mouthwash down the drain?
“Not necessarily,” says Dr. Brookes, “there is concern, but on the other hand, we also have a lot of evidence that gum disease itself is associated with uncontrolled diabetes and cardiovascular disease, so keeping our healthy teeth and gums is more important. than ever, especially when so many people can’t even get an NHS dentist right now.
“As a dentist, my advice is different for each patient, asking each time whether the benefits of using mouthwash outweigh the personal risks to them.”