One of my early childhood memories was the sound of my Dad gargling water after he brushed his teeth. He taught me to do the same, with some embellishments if my throat were sore.
In that case, I’d add a pinch of salt to the water, tilt back my head and gargle for a full minute before spitting into the sink.
In 2007, Japan’s Inter-ministerial Avian Influenza Committee included frequent gargling in its infection-prevention measures, along with regular hand washing and face masks. The many small-scale studies done over the years on preventing common colds might have guided their recommendations.
A two-month trial run by Kyoto University’s School of Public Health, for example, divided 387 healthy volunteers aged 18 to 65 into three groups:
Group 1 gargled with plain water at least three timed daily.
Group 2 gargled with a diluted povidone-iodine solution.
Group 3 continued with their “usual care.”
The water-garglers, it turns out, experienced about one-third the colds of BOTH the iodine-gargling and usual-care groups!
In this 2020 New York Times article, Dr. Neal Naito, former director of public health for the U.S. Navy, mentions similar clinical studies.
In this one from Edinburgh, participants performed nasal irrigation and gargled up to six times daily with a solution of 1 heaping teaspoon of salt dissolved in 1 cup of water.
They experienced a significant reduction in colds and upper respiratory tract infections.
Although Dr. Naito didn’t suggest frequent gargling would prevent COVID-19, he still recommended it:
“Over all, looking at gargling from a risk-benefit ratio perspective, there seems to be little downside to frequent gargling. It’s a low-cost intervention, and may help to treat a sore throat. Whether gargling will actually fight off colds or flu, however, let alone the more serious coronavirus that is currently circulating, remains indeterminate as the current evidence base is limited.”
My Dad may have been on to something with his daily gargling routine!
I’ve rarely practiced gargling as an adult. But after reading these studies, gargling with water several times a day may be a good habit to start – especially during the cold season.