ANAHEIM, Calif. – A new study presented this week at the annual meeting of the American College of Allergy, Asthma and Immunology (ACAAI) suggests that regular saline rinses may help reduce hospitalization rates in patients with COVID-19.
The study, conducted between 2020 and 2022, divided 58 patients aged 18-65 with positive PCR tests for SARS-CoV-2 into two groups – one receiving a low-dose saline rinse regimen and one receiving a high-dose regimen. Patients were instructed to perform nasal irrigation and gargling with the saline solutions four times per day for two weeks.
After excluding dropouts, the low-dose group contained 27 patients using a saline solution of 2.13 grams of salt dissolved in 8 ounces of warm water. The high-dose group had 28 patients using a solution of 6 grams of salt in 8 ounces of water.
Hospitalization Rates Significantly Lower Than General Population
The study found that hospitalization rates in the low-dose (18.5%) and high-dose (21.4%) saline groups were significantly lower compared to a reference population of 9,398 COVID-19 patients in the same age range during the study period. The hospitalization rate for that general population was 58.8% – more than double that of the saline rinse groups.
“Our goal was to examine saline nasal irrigation and gargling for possible association to improved respiratory symptoms associated with coronavirus infection,” said Dr. Jimmy Espinoza, co-author of the study.
“We found that both saline regimens appear to be associated with lower hospitalization rates compared to controls in SARS-CoV-2 infections. We hope more studies can be done to further investigate the association.”
No Significant Difference Between Saline Dose Levels
The study found no significant differences in hospitalization rates or other major health outcomes between the low-dose and high-dose saline groups.
“There were no significant differences in the primary or secondary outcomes of the study between these two groups,” said lead author Sebastian Espinoza.
Both saline regimens were also associated with similar durations of COVID-19 symptoms.
Potential Mechanisms of Action
Researchers speculate that regular saline rinses may provide protective effects in COVID-19 patients through several mechanisms:
- Helping clear mucus secretions and flush viral particles from the nasal passages and throat
- Providing moisture to help soothe inflammation and irritation of respiratory tissues
- Enhancing mucociliary clearance – the natural self-cleaning process of the airways
- Boosting local immunity – saline may stimulate protective antimicrobial proteins
More Research Needed
While suggesting a positive effect for saline rinsing in COVID-19, the researchers emphasize that larger, randomized controlled studies are still needed to conclusively demonstrate effectiveness and optimal dosing regimens.
“The study is intriguing and underscores the potential benefits of saline nasal rinsing, but it has significant limitations including small sample size and lack of randomization or blinding,” said Dr. Rachel Miller, an infectious disease specialist not involved in the research.
“I look forward to seeing the results replicated in larger placebo-controlled trials,” Miller added. “In the meantime, saline rinses are very low risk and may provide some relief from nasal symptoms.”
Experts also caution that saline rinses should never be used as a replacement for COVID-19 vaccination, social distancing, masking, and other protective measures.
Other Potential Applications
Beyond COVID-19, experts say the findings may have implications for managing symptoms of other upper respiratory infections like the flu, common cold, and sinusitis. Saline nasal irrigation is already routinely recommended for chronic sinus issues.
“Saline rinses have been used for centuries to provide relief during cold and allergy seasons,” said Dr. Ron Eccles, a professor of respiratory medicine. “This study gives us more evidence that saline could also provide some immediate benefit for viral respiratory infections by improving mucus clearance and possibly reducing viral load in the nose and throat.”
More research is underway to evaluate whether saline could also help shorten duration or reduce spread of contagious illnesses like influenza. For now, experts emphasize maintaining a healthy level of skepticism until larger randomized trials are completed.