Dental Health Tips: Mouthwash Can Hinder the Benefits of Exercise

Mouthwash Can Hinder the Benefits of Exercise

Mouthwash reduces exercise induced lower blood pressure

Post exercise hypotension describes a syndrome that moderate exercise leads to lowered blood pressure. In a study published in the Journal of Free Radical Biology and Medicine Volume 143, 1 November 2019, Pages 252-259, the effects of oral bacteria in this phenomenon were studied. It was found that the use of mouthwash immediately after exercise eliminated the beneficial effects of exercise in lowering blood pressure for at least 2 hours afterwards.

The conclusion drawn was that oral bacteria were especially important in achieving this effect. Nitric oxide gas is continually produced by Catalase enzymes in the nose and paranasal sinuses and is vented into the nasal airways. This gas reaches the lungs during breathing. The nitric oxide present in the mouth degrades into nitrate and is then changed into a compound called nitrite by the bacteria present in the mouth. The study says: “When that nitrite is swallowed, it gets absorbed back into the blood stream and turns back into nitric oxide — which widens blood vessels and lowers blood pressure.”

So, the oral bacteria in the mouth creates a cycle of nitric oxide to nitrate to nitrite back to nitric oxide, that extends the blood pressure benefits of exercise, resulting in post-exercise lower blood pressure.

The study looked at the effect mouthwash, which reduces oral bacteria, would have on post-exercise blood pressure. After twice running on a treadmill for ½ hour two hours after each treadmill session blood pressure was monitored.

Then participants rinsed their mouths with a liquid which was either antibacterial mouthwash or mint-flavored placebo water. Blood pressure was measured, and blood and saliva samples were taken both before and after exercise sessions. The results showed placebo rinse subjects had a reduction in blood pressure of about 5 mmHg one hour after the treadmill. Those who rinsed with actual mouthwash only saw an average reduction of 2.0 mmHg after one hour and 0.0 after two hours. This indicates that the blood pressure-lowering benefits of exercise were reduced using mouthwash following a workout. In addition, nitrite levels did not increase after exercise when using mouthwash.

The conclusion to be drawn is to use mouthwash sparingly right after or better yet many hours or even a day after exercise to maintain the beneficial advantage of exercise induced lowered blood pressure moderated by nitric oxide.