Is mouthwash really harmful to the heart? Let us tell you what we know.

 

Claims are being made in social media videos that mouthwash can raise blood pressure and have an adverse effect on heart health.

Some videos explain that this is because mouthwash eliminates "beneficial" oral bacteria that are important for cardiovascular health.

While these claims are shocking, there is no need to throw away mouthwash immediately. The reality is much more complex.

Various types of bacteria inhabit our mouths. These bacteria form a balanced and diverse microbial community that prevents the overgrowth of specific disease-associated bacteria, supports normal metabolic functions, and contributes to overall health as well as oral health.

One of the important roles of these oral bacteria is converting nitrates contained in food (primarily leafy vegetables, etc.) into nitrites.

When we consume nitrites, they are converted into nitric oxide in the body. This process is described by the nitrate-nitrite-nitric oxide pathway, which occurs through the intestinal salivary pathway. This is one example of how bacteria contribute to maintaining our body's health.

Nitric oxide plays an essential role in regulating blood pressure and maintaining brain and muscle function.

However, some online influencers claim that mouthwash is harmful to heart health because it affects "beneficial" bacteria that produce nitric oxide.

Mouthwash and heart health link

Several small-scale studies have revealed that using mouthwash can alter the balance of bacteria in the oral cavity. This can reduce the bacteria's ability to convert nitrates from vegetables into nitrites, which are necessary for the body to produce nitric oxide.

A study involving 19 healthy adults showed that using chlorhexidine mouthwash for 7 days resulted in a slight increase in blood pressure and a decrease in nitrite levels.

Additionally, one intervention study reported a significant increase in blood pressure in 27 healthy adults who used 0.12% chlorhexidine gluconate mouthwash twice a day for one week.

Another study involving 15 hypertensive patients showed a further increase in blood pressure when chlorhexidine was used for 3 days.

An important fact easily overlooked in these online social media videos is the type of mouthwash used in the studies.

Many studies investigating the link between mouthwash use and blood pressure have used chlorhexidine on their participants. This product is an over-the-counter mouthwash with powerful antiseptic effects, and short-term use is recommended for individuals with gum disease or those requiring antibacterial action after dental procedures.

Chlorhexidine helps manage infections by inhibiting oral bacteria, particularly those that convert nitrates to nitrites. Therefore, it is an ideal mouthwash for researchers studying the nitrate-nitrite-nitric oxide pathway.

However, this implies that research results may differ from the effects observed with the use of standard mouthwashes.

An experiment was conducted on 12 healthy adults to investigate the effects of three types of mouthwash (with water used as a control) on oral bacteria.

The researchers measured the amount of nitrates converted to nitrites by oral bacteria after the participants drank nitrate-rich juice. When water and a mild mouthwash (a product without irritating ingredients like chlorhexidine) were used, the typical reaction of nitrates being converted to nitrites occurred.

However, cetylpyridinium chloride mouthwash (which also has a strong antibacterial effect) partially inhibited the conversion of nitrates to nitrites. The strongest chlorhexidine mouthwash almost completely blocked this process.

This result is consistent with its strong antibacterial effect. Additionally, it was found that systolic blood pressure increased when using the strong mouthwash.