Over-the-counter mouthwash use, nitric oxide and hypertension risk
Where: University of Puerto Rico Medical Sciences Campus, Harvard T.H. Chan School of Public Health, and the University of Alabama at Birmingham
Published: 2020 April, Blood Pressure
This study demonstrated that long-term routine use of conventional mouthwash is associated with increased risk of hypertension (high blood pressure).
What it looked at
1028 participants between ages 40-65 had their blood pressure evaluated by physician at baseline, then again at a 3-year follow-up exam. Participants were evaluated for age, sex, smoking, physical activity, waist circumference, alcohol intake, diabetes, cardiac medication use, and mouthwash use.
What it found
People who used mouthwash twice per day had a higher incidence of hypertension (with an incidence ratio of 1.85) compared to less frequent users, even when controlling for multiple confounders such as age, sex, smoking status, and physical activity. Non-users of mouthwash had the lowest incidence of hypertension.
Why It Matters
Research has demonstrated the link between the oral microbiome and levels of nitric oxide (https://pubmed.ncbi.nlm.nih.gov/28353075/). Antibacterial mouthwash is known to disrupt the oral microflora, and reduce overall levels of microbes in the mouth. However, the impact of mouthwash on overall long-term health had yet to be determined, except in small short-term trials associating mouthwash with a reduction in salivary and plasma nitrate and nitrite (https://pubmed.ncbi.nlm.nih.gov/25359409/).
This landmark study demonstrated that extended disruption of the oral microbiome by mouthwash lead to long-term effects on cardiac health through disruption of bacterial nitrate reduction pathways responsible for generating nitric oxide. This study also lays a foundation for engineering the oral microbiome in the management of hypertension. Maintaining a healthy oral microbiome is a key component of cardiac health.