What’s behind the gargling claim, and is there any medical proof that gargling may help to fight coronavirus or other respiratory infections?

(Not everyone, though, can gargle effectively, including some people with neck pain, stroke or dementia, as well as children generally under the age of 8.) Most of the early studies suggesting that gargling may help to prevent and treat upper and lower respiratory infections, not surprisingly, come from Japan.

The most intriguing findings center on the use of an over-the-counter povidone-iodine oral gargle solution, which has been commonly used for decades by people in Japan and elsewhere to treat a sore throat.

In a small Japanese experimental study from 2002, 23 patients with chronic respiratory disease gargled four or more times a day with a povidone-iodine solution.

Researchers found that, compared to the number of acute respiratory infections before the group started gargling, regular gargling for several months to two years with the povidone-iodine solution led to an approximate 50 percent reduction in the incidence of acute respiratory infections.

Laboratory studies have also suggested potential benefits from gargling, though a major limitation of these test-tube studies is that what works in the lab may not translate to health benefits for patients.

A recent intriguing clinical study from England involving 66 patients suggested that using a homemade hypertonic saline solution for nasal irrigation and gargling significantly reduced the incidence of flu and colds.

One study even suggested that gargling with tap water alone may even be helpful in reducing the incidence of upper respiratory infections in a healthy population, although a later study did not confirm this finding