Want a Running PB? Put Down That Mouthwash
My dentist is back and this time she’s coming for your mouthwash
Not content with berating runners for their poor dental health, my dentist has a new target in her sights: mouthwash. Here’s why…
I knew I’d made a mistake the minute I asked. Natasha sighed deeply and proceeded to deliver the TED talk she’d waited to give all her life and it started like this.
“If you want a PB, you should stop using mouthwash immediately.”
Let’s backtrack a second. If you read my last article (and thank you for your kind comments), you’ll know my dentist wants you to stop running. Not out of personal vendetta but because high-intensity training leads to stress, which leads to inflammation in the body which, in turn, leads to gum disease. Not convinced? This 2018 study of Olympic athletes will blow your mind.
My dentist also wants me to point out she’s not, as previously stated, a dental nerd, she is in fact a health nerd. She’s one of the most terrifyingly clever people I’ve ever met.
And she really doesn’t like mouthwash.
It’s All Science
As Natasha proceeded to explain mouth science to me, I resolved to remember all the names of the chemical reactions and enzymes as they washed over my ears. Dear reader, I do not remember a single one, but I have found several studies that appear to back up her claims. It makes for an interesting read.
But not that interesting if you don’t care for the science part.
So here’s the takeaway: regular use of mouthwash reduces certain oral bacteria in your mouth. Far from bad, these bacteria are essential for kickstarting a process called Post-Exercise Hypotension (PEH), or the lowering of your blood pressure after exercise — like a run for example.
Antibacterial mouthwash is essentially like taking a hammer to crack a tiny nut. It might well kill off some of the bacteria in your mouth that lead to bad breath or plaque, but equally, it kills off bacteria designed to help your body recover better from exercise.
Here’s what researcher Craig Cutler says. He, along with eight colleagues, conducted an experiment in 2019 looking specifically at PEH and oral bacteria.
“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. If they are removed, nitrite can’t be produced and the vessels remain in their current state.”
The Fall Out
If Cutler and company are right, then it’s not just your post-run recovery at stake, it could cost you your post-run improvements. If your body is prohibited from recovering effectively, those gains you made on your hill sprints are going to struggle to translate into long-term success.
It also means Natasha was right AGAIN about good oral health being key to good overall health. This is becoming unbearable.
And look, if you want it in even starker terms, here’s what else the study says. It’s enough to make you throw your away Listerine (other brands of mouthwash are available for responsible disposal):
“These results show that the blood pressure-lowering effect of exercise was diminished by more than 60% over the first hour of recovery, and totally abolished two hours after exercise when participants were given the antibacterial mouthwash.”
All that hard work and a quick swig of mouthwash reduces the blood pressure-lowering effect of exercise by MORE THAN 60%. I’ll pass.
Now it would be way too easy to follow up this study with a deep dive into gut health, supplements like nitrate-rich beetroot and all that jazz, but I only have a finite number of hours left on earth so we’ll leave that for another time. Or unless Natasha raises it at our next appointment.
Speaking of which, I’ll be in that chair again in a couple of week’s time, under Natasha’s expert care – anything dental/running related you want me to ask her?
Drop me a line: caroline@carolinekellywriter.com or leave a comment.
