Researchers have started to test whether a home remedy for the common
cold might help with early symptoms of COVID-19. Rinsing the nostrils
and gargling with salt water has been used by some as a way of treating
cold symptoms for many years. A small pilot study in just over 60 adults
with colds found that most people who used salt water rinsing thought it
made a difference to their symptoms. They also found that their cold
lasted a day or two less than people who did not use salt water rinsing.
Some of the people in this study had colds caused by earlier human
coronaviruses. While this study does suggest some benefit of saline
rinsing for people with colds, we can’t be sure that some of this wasn’t
down to people rating their symptoms as improved because they expected
the salt water rinse to be helpful. The same researchers are repeating
their study in people with early symptoms of COVID-19. COVID-19 is
caused by a new and more serious type of coronavirus (SARS-CoV-2) than
those that cause the common cold, so we don’t yet know whether salt
rinsing will help.
News outlets including the Evening Standard in the UK carried stories about the new salt water study. The Standard’s headline implies that research already backs up the theory, when in fact the study has only just started. We won’t know if salt water rinsing has any effect until it has been completed.
Researchers from the University of Edinburgh carried out the trial of salt water rinsing and the common cold and are starting a similar trial in people with COVID-19. Their study was a small pilot study with results from 61 adults with a cold but who were otherwise healthy. The participants had developed symptoms in the last 48 hours and were randomly allocated to either gargle and clear their noses with a salt water solution, or to just carry on doing whatever they would normally do to treat a cold. They found that participants who used the salt water solution reported fewer coughs, less congestion, and one to two days’ shorter duration of cold symptoms than those who didn’t. Some of this impact may have been down to people expecting to feel better after receiving the treatment being studied (the salt solution) than when they have no treatment. The new coronavirus pandemic prompted the researchers to look back at their results, as some common colds are caused by older types of coronavirus. When just looking at the 15 people whose colds were caused by coronaviruses, they also showed a trend for reduction in symptoms with the salt water gargling and rinsing. This led the researchers to think that it was worth repeating the study in people with COVID-19.The researchers are inviting people over 18 in Scotland with symptoms of COVID-19 that started in the previous 48 hours to take part in the new study.
Gargling and nose-washing are not currently recommended to improve the symptoms of COVID-19 or to prevent infection. The Harvard TH Chan School of Public Health India Research Centre says: “There is no evidence that regularly gargling [saltwater or saline] has protected people from infection with the new coronavirus. While this may help soothe a sore throat, this practice will not prevent the virus from entering your lungs.”