Saline nose drops may shorten colds and cut transmission, trial hints

For centuries, the common cold has eluded effective treatments — but now, a study hints that simple nose drops may help subdue the virus, shortening symptoms by days and reducing the likelihood of spread to others.

The nose drops contain just two ingredients: water and salt. The solution is known as " hypertonic saline ," meaning it contains a higher concentration of salt than is typically found in bodily fluids.

"We presume that the impact of the hypertonic saline drops was to reduce viral loads," or the amount of virus in the body, said study co-author Dr. Steve Cunningham , a professor of pediatric respiratory medicine at the University of Edinburgh.

The team didn't test this idea directly, but "it is commonly understood that higher viral loads have a greater capacity for transmission," he said.

Related: When did humans start getting the common cold?

Cutting the length and transmission of colds by even a little could have big impacts, Cunningham added. The average adult experiences two to four colds per year, but these numbers are about twice as high in children, in part because they have yet to build immunity to the more than 200 cold-causing viruses . These illnesses are typically mild but can sometimes lead to severe complications .

And even mild colds come at a cost — doctor visits can be inconvenient and costs of treatments add up, especially if the illness results in missed work or school time.

Because children catch colds often, they're the likeliest source of infection for other members of their households. Available cold remedies are aimed at easing people's symptoms as they wait out the infection. Thus, "reducing the duration of cold symptoms could help reduce impacts on children and also on families, with parents able to return to their usual activities sooner," Cunningham told Live Science

People have long used saltwater nose drops and sprays to relieve cold symptoms, as these can thin or clear mucus that contributes to congestion. The researchers wondered whether saltier nose drops would add a chemical effect, boosting the ability of cells in the nose to fight cold viruses. There’s evidence to suggest the chloride in salt might drive such an effect.

The team gave 150 young children who developed colds hypertonic saline nose drops, which contained 2.6% salt instead of the standard 0.9% . Another 151 children with colds received only the usual care their families would provide, such as rest, fluids and pain- and fever-reducing medications.

Parents assigned to give their children nose drops as soon as their cold symptoms appeared reported that their children's illnesses lasted an average of six days — two fewer days than for children who weren't given the drops.

Additionally, 46% of those promptly treated children likely passed their illness to another person, as evidenced by a household member getting an upper respiratory tract infection. By comparison, 64% of the children who received usual care shared their colds with others.

The positive effects of the nose drops disappeared when they were started more than 24 hours after the kids first developed symptoms, New Scientist reported . This suggests that the treatment may be effective only in the early stages of a cold.

Notably, parents mixed the saline solution for the nose drops themselves in the study. "Each parent knew whether or not their child was being treated with hypertonic saline drops," Dr. Lauren Beene , a pediatrician at University Hospitals in Ohio who was not involved in the research, told Live Science by email.

"That parent was then asked to score their child's symptoms," she emphasized. "As parents, when we know we are doing something to help our child feel better, we may perceive them as seeming to feel better sooner."

To make sure the children's quicker recovery was not just the placebo effect , the researchers could consider conducting future studies that compare the effect of hypertonic saline to that of plain water or drops with less salt. If the same effects showed up across all the drops, you might chalk that up to the placebo effect.

— Why is it hard to hear when you have a cold?

— Did pandemic lockdowns stunt kids' immune systems long-term?

— Common cold virus may predate modern humans, ancient DNA hints

Assuming the saline drops really work, "this extremely cheap and simple intervention has the potential to be applied globally," Dr. Alexander Möller , a pediatrician and pulmonologist at the University Children's Hospital Zürich who was not involved in the study, said in a statement .

The new research was presented Sept. 8 at the European Respiratory Society Congress in Vienna. It has yet to be published in a peer-reviewed journal.

This article is for informational purposes only and is not meant to offer medical advice.

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