What’s really going on when you rinse a cap-load of antibacterial chemicals around your mouth?
As a new study shows, the downstream effects can be surprising, and far-reaching too, affecting much more than just your dental wellbeing.
In an experiment led by scientists from the UK and Spain, researchers found that the simple act of using mouthwash after exercising can reduce one of the benefits of exercise: lowering blood pressure.
When you exercise, your blood vessels open in response to the production of nitric oxide, which increases the diameter of blood vessels. This process is called vasodilation, and it increases blood flow circulation to active muscles.
Evidence has shown that circulation stays high (meaning blood pressure is lowered) even after exercise – thanks to how bacteria interact with a compound called nitrate, which forms when nitric oxide degrades.
Nitrate can be absorbed in the salivary glands and excreted with saliva in the mouth. Some species of bacteria in the mouth can use nitrate and convert into nitrite – a very important molecule that can enhance the production of nitric oxide in the body.
Once nitrite is produced and swallowed with saliva, it becomes absorbed into blood circulation and reduces back to nitric oxide, which keeps blood vessels wide and lowers blood pressure.
But according to this study, it looks like this biological mechanism can be significantly interrupted if anti-bacterial mouthwash gets added into the post-exercise mix.
The results showed that at one hour after the treadmill session, average reduction in systolic blood pressure in the placebo group was –5.2 mmHg (millimetres of mercury). The reduction in the mouthwash-using group was much lower, showing an average of –2.0 mmHg at the same point in time.
At the end of the monitoring window, two hours after the treadmill session, the mouthwash group showed no sign of blood pressure reduction stemming from the exercise, whereas the placebo group still showed a significant reduction compared to their pre-exercise values.
“This is the first evidence showing that the nitrate-reducing activity of oral bacteria is a key mechanism to induce the acute cardiovascular response to exercise during the recovery period in healthy individuals,” the authors explain.
While it’s only a small study, it serves as an important reminder of how not all bacteria are necessarily bad for us – and that ingesting antibacterial chemicals that indiscriminately terminate mouth-dwelling microbes could hamper important biological processes necessary for good health.
“These findings show that nitrite synthesis by oral bacteria is hugely important in kick-starting how our bodies react to exercise over the first period of recovery, promoting lower blood
pressure and greater muscle oxygenation,” says one of the team, nutritionist Craig Cutler.
“In effect, it’s like oral bacteria are the ‘key’ to opening up the blood vessels. If they are removed, nitrite can’t be produced and the vessels remain in their current state.”
Dr. Frank E. Kaden, D.C.
1927 Artesia Blvd., #7
Redondo Beach, CA 90278
Original Study Online at: https://www.sciencedirect.com/science/article/pii/S0891584919307610?via%3Dihub