Mouthwash – yes or no?

Regular, electric and interdental toothbrushes, toothpaste, water flossers, dental floss, mouthwash – dental hygiene products are numerous. Widely available and easy to use, they require discipline and routine, but using mouthwash requires caution as well. Why is that so?

The crux of the issue

Nitric oxide (NO) is an important molecule in the human body seeing as it causes vasodilatation, lowers blood pressure and increases blood flow and circulation. However, the human body lacks the enzymes necessary to convert food-sourced nitrates to nitrites, a molecular form the body is able to harness. Humans, like other mammals, do not possess nitrate reductase; instead, xanthine oxidoreductase (XOR) catalyses the reduction of nitrites to nitric oxide (NO). Owing to their very similar structures, aldehyde oxidase and sulfite oxidase fulfill the same role.

Due to its lack of nitroreductase, the human body relies on bacteria from the oral microbiome to convert nitrates to nitrites while chewing nitrite-rich food such as leafy greens, for example spinach and kale. Lowered blood pressure can be noticed immediately after consumption and in the following 90 minutes.

The problem occurs when using mouthwash to maintain oral hygiene. Clinical research has shown that antibacterial mouthwash reduces the number of nitrate-reducing bacteria, decreases systemic bioavailability of NO and causes dysbiosis in the oral microbiome.

Harmful effects on the organism

Studies have demonstrated that individuals who often use antiseptic mouthwash display a 50% higher risk of developing diabetes as well as a doubled risk of developing hypertension. Other research studying the effect of mouthwash on the risk of developing diabetes and hypertension has shown a mutual correlation. However, it has to be noted that the research population was already in somewhat bad health.

Studies on antiseptic mouthwash containing chlorhexidine have also demonstrated other harmful effects such as modified pH levels in the oral cavity and modified lactate, nitrate and nitrite concentrations in saliva.

To use mouthwash, or no?

Destroying bacteria in the oral cavity on a daily basis also eliminates bacteria that are necessary and beneficial. Does that mean antiseptic, antibacterial mouthwash should be avoided?

The answer is – no. The use of mouthwash is encouraged in certain conditions when recommended by a doctor or pharmacist.

Detrimental effects on health have been noted in individuals using mouthwash two or more times a day, while one use a day is still considered safe.

Mouthwash that preserves “good” bacteria, i.e. the mildest mouthwash, is any formulation not containing alcohol.

Translated by: Anđela Jakiša