Gossip and fake news make me angry.
A recent study began making the newspaper and social media rounds this week claiming that mouthwash “inactivates” coronaviruses, and halts their spread. The study, which was published last month in the Journal of Medical Virology, looked only at a coronavirus called 229E that causes common colds— not covid-19.
I think it’s silly for you to start buying stock in Listerine, and I warn you against over-interpreting these test results. The study did not include or investigate covid-19, specifically. Indeed, the two viruses are in the same family, and, in broad strokes, look similar. However, microbiologists warn that the two viruses should not be thought of as interchangeable.
The researchers tested a watered-down mixture of Johnson’s baby shampoo— which is sometimes used to flush out the inside of the nose— and mouthwashes made by Listerine, Crest, Orajel, Equate and C.V.S. They flooded 229E coronaviruses, which had been grown in human liver cells in the lab, with these chemicals for 30 seconds, 1 minute or 2 minutes— longer than the typical swig or spritz into a nose or mouth. Around 90 to 99 percent of the viruses could no longer infect cells after this exposure, the study found.
I side with the experts: because the study didn’t recruit human volunteers to gargle the products in question, the findings have limited value.
Research at Yale goes on to say that even if people did a thorough job coating the inside of their mouths or noses with a coronavirus-killing chemical, a substantial amount of the virus would still remain in the body. The new covid-19 infiltrates not only the mouth and nose but also the deep throat and lungs, where mouthwash and nasal washes never enter (hopefully).
Relying on mouthwash or a nasal rinse to rid the body of this infectious virus would be about as futile as trimming the top of a cluster of weeds, paying the roots little mind, and expecting the garden pests to disappear. I’m all for using mouthwash to reduce your chance of getting gingivitis, but I don’t think gargling with mouthwash is going to have a meaningful impact on your ability to transmit this virus.
I promise to continue my research and report the latest findings to you.