Dr Jeremy London, a board-certified cardiovascular surgeon, has revealed he avoids alcohol-based mouthwash due to its potential to increase blood pressure. In a social media video titled "stop using mouthwash," he explained two reasons: first, mouthwash kills healthy bacteria in the mouth, disrupting the oral environment; second, it interferes with a chemical reaction that helps control blood pressure.
How Mouthwash Affects Blood Pressure
In an interview with NBC's Today programme, Dr London elaborated that beneficial bacteria in the mouth help the body produce nitric oxide, which dilates blood vessels and regulates blood pressure. Antibacterial mouthwash kills these bacteria, interrupting nitric oxide production. "You can actually increase your blood pressure simply by killing the bacteria in the mouth," he said, adding that those predisposed to high blood pressure may be at greater risk.
Scientific Evidence
A study published in the Blood Pressure journal involving over 1,000 participants found that frequent use of over-the-counter mouthwash was associated with an increased risk of hypertension, independent of other risk factors. Another study in Science Direct described "unequivocal evidence" that disrupting oral bacteria with mouthwash suppresses nitric oxide production and negatively impacts blood pressure.
Expert Warnings
Dr London is not alone in his caution. Dentist Kami Hoss compares using strong mouthwash to gardening: "If there was a weed growing in your garden, you wouldn’t just throw acid and weed killer all over and kill everything." He warns that sterilising the mouth leaves only the toughest microbes, disrupting the oral microbiome. Dr Hoss also notes that overall oral health is poor, with people either neglecting their mouths or over-sterilising them.
Practical Advice
Dr London advises avoiding alcohol-based mouthwashes, especially for those with high blood pressure or a family history of hypertension. He recommends maintaining oral hygiene through brushing and flossing without disrupting the natural balance of oral bacteria.
