Study warns excessive mouthwash use could affect heart health
. . . may disrupt nitric oxide and raise hypertension risk
A scientific study has found that frequent use of over-the-counter antibacterial mouthwash may be linked to a higher risk of developing high blood pressure, raising new questions about the long-term effects of routine oral hygiene products.
The research, published in a peer-reviewed medical journal, examined data from the San Juan Overweight Adults Longitudinal Study (SOALS), which followed more than 500 overweight and obese adults aged 40 to 65 over a three-year period. Participants had no prior diagnosis of hypertension at the start of the study.
Researchers focused on the impact of mouthwash use on nitric oxide, a molecule that plays a critical role in regulating blood pressure. Nitric oxide is partly produced through oral bacteria that convert dietary nitrates into biologically active compounds.
Antibacterial mouthwashes can disrupt these beneficial bacteria, potentially reducing nitric oxide availability in the body.
The study found that participants who used mouthwash twice a day or more were significantly more likely to develop hypertension than those who used it less frequently or not at all.
Frequent users showed nearly double the risk of developing physician-diagnosed high blood pressure during the follow-up period, even after adjusting for age, sex, smoking, physical activity, waist size, alcohol intake, baseline blood pressure, diabetes status and cardiac medication use.
Importantly, the association remained consistent among non-smokers and was not explained by other potential confounding factors.
However, the researchers noted that blood pressure measurements taken during a single study visit did not show the same association, suggesting that long-term effects may be more relevant.
The authors cautioned that while mouthwash remains effective for oral hygiene, excessive routine use—particularly antibacterial formulations — may have unintended cardiovascular consequences.
They emphasized the need for further research to better understand the balance between oral health benefits and systemic health risks.
