TL;DR
Recent clinical work links regular saline nasal irrigation to shorter, milder colds, with a large 2024 trial reporting about a 20% reduction in illness duration. Researchers propose salt-driven antiviral activity in nasal cells and improved mucus defenses, though optimal concentrations and routines remain unsettled.
What happened
Researchers have returned attention to saline nasal irrigation, a practice rooted in ancient Ayurvedic medicine, after a series of modern studies found measurable benefits against respiratory infections. A major 2024 trial with nearly 14,000 participants funded by the UK’s National Institute for Health and Care Research found that using a saline spray three to six times daily at the first sign of infection shortened illness duration by roughly 20 percent; a later follow-up reported similar effects. Investigators led by Paul Little say chloride from saline is taken up by nasal and throat cells and converted into hypochlorous acid, which can inhibit viral replication and reduce viral load. Additional studies suggest saline boosts neutrophil activity and helps mucus more effectively trap viruses. Clinical interest rose after early skepticism during the Covid era shifted as evidence accumulated, including a study that linked post–Covid-positive saline irrigation to a much lower risk of hospitalization. Open questions remain about the best salt concentration, dosing, and delivery method.
Why it matters
- Could shorten the average duration of common colds, lowering personal illness burden and lost productivity.
- Low-cost, widely available interventions (sprays or simple irrigation) may be scalable and accessible.
- Evidence points to multiple plausible biological effects: reduced viral replication, enhanced immune cell activity, and improved mucus trapping.
- If standardized, the practice could become a complementary public-health measure during high-transmission seasons.
Key facts
- A 2024 trial of nearly 14,000 people found about a 20% reduction in illness length when saline spray was used 3–6 times daily at symptom onset.
- Lead researcher Paul Little reports saline chloride is metabolized by nasal cells into hypochlorous acid, which can inhibit viral replication.
- A separate study found people who used saline irrigation for two weeks after testing positive for Covid were over eight times less likely to require hospitalization.
- Saline may increase neutrophil activity and help mucus envelop and clear viral particles, reducing viral load in the nose.
- Nasal irrigation has historical roots in Ayurveda and has been part of Western medical inquiry since the 19th century.
- Delivery methods include traditional Neti pots and inexpensive pump‑action saline sprays; the large trial achieved results with a pump spray.
- A simple homemade solution cited by clinicians mixes eight ounces of water with half a teaspoon of salt.
- Safety guidance stresses using water safe for drinking—boiled, distilled, or appropriately treated—to avoid rare but serious infections like those from Naegleria fowleri.
- Key uncertainties persist about optimal salt concentration, exact dosing schedules, and the best application method for different people.
What to watch next
- Ongoing and planned studies testing whether routine nasal irrigation reduces transmission, not just symptom duration.
- Clinical trials comparing methods (spray vs. irrigation vs. Neti pot), salt concentrations, and dosing schedules to establish standardized guidance.
- Research into adjunctive saline gargling or throat applications, since some respiratory viruses also enter via the mouth and throat.
Quick glossary
- Saline nasal irrigation: The practice of flushing or spraying the nasal passages with a saltwater solution to clear mucus and contaminants.
- Hypochlorous acid: A reactive compound produced in immune processes that can have antimicrobial and antiviral effects.
- Neutrophils: A type of white blood cell that helps defend against infections by ingesting and destroying pathogens.
- Neti pot: A teapot-like device traditionally used to pour saline through one nostril and out the other for nasal irrigation.
- Viral load: The quantity of virus present in a given volume of tissue or fluid, often linked to severity and transmissibility.
Reader FAQ
Can nasal rinsing prevent a cold entirely?
Studies show it can reduce duration and severity and may lower viral load, but complete prevention is not guaranteed.
Is nasal irrigation safe?
Generally considered safe when using water that is safe to drink (boiled, distilled, or properly treated); contaminated water can pose rare risks.
How often should I use saline if I want to try it?
In the large trial, a pump‑action saline spray used three to six times daily at symptom onset showed benefit; optimal routines are still under study.
Is this recommended for children?
not confirmed in the source
DAVID COX SCIENCE JAN 7, 2026 11:18 AM The Ancient Art of Nasal Rinsing Might Protect You From a Cold New research has given credence to a 5,000-year-old practice. PHOTO-ILLUSTRATION:…
Sources
- The Ancient Art of Nasal Rinsing Might Protect You From a Cold
- Recent studies prove the ancient practice of nasal irrigation …
- Are Sinus Rinses Safe To Use?
- A Drug-Free Nasal Spray May Shield Against Respiratory …
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