How can mouthwash interfere with the benefits of exercise?


Surprising new research shows that
antibacterial mouthwash can limit
the cardiovascular benefits of exercise. The effect of mouthwash on mouth bacteria interferes with a complex molecular mechanism that usually sustains the blood pressure-lowering effects of exercise.
Antibacterial mouthwash may help oral health, but new research shows that it interferes with the cardiovascular benefits of exercise.
The bacteria in our mouths play a key role in our health. An analysis of oral microbes from tens of thousands of people, for example, found an association between bacteria that can cause gum disease and a higher risk of esophageal cancer.
Other studies have exposed the mechanism by which a mouth bacterium can speed the growth of colorectal tumors and shown how oral bacteria can impair respiratory health. Finally, some research has also linked gum disease with higher dementia risk.
New research zooms in on another fascinating role that oral bacteria play in our health — namely, that they help us get cardiovascular benefits from exercise.
Raul Bescos, a lecturer in dietetics and physiology at the University of Plymouth, United Kingdom, is the lead author of the new study, which shows how mouth bacteria mediate the blood pressure-lowering effects of exercise and how the use of antibacterial mouthwash interferes with this process.
The new paper appears in the journal Free Radical Biology and Medicine.
The study’s lead author explains the motivation for the new research, saying, “Scientists already know that blood vessels open up during exercise, as the production of nitric oxide increases the diameter of the blood vessels (known as vasodilation), increasing blood flow circulation to active muscles.”
“What has remained a mystery is how blood circulation remains higher after exercise, in turn triggering a blood pressure-lowering response known as postexercise hypotension.”
Nitric oxide breaks down into nitrate, explains Bescos. This process is the beginning of a circular molecular reaction, which, in the end, results in the sustained blood pressure-lowering effects of exercise.
“And when nitrite in saliva is swallowed, part of this molecule is rapidly absorbed into the circulation and reduced back to nitric oxide. This helps to maintain a widening of blood vessels, which leads to a sustained lowering of blood pressure after exercise.”
“We wanted to see whether blocking nitrate’s ability to convert into nitrite by inhibiting oral bacteria [through the use of mouthwash] would have any effect on postexercise hypotension.”