Saline (salt water) irrigation of the nasal passages can improve nasal mucociliary clearance. Many patients with chronic nasal and sinus problems use nasal saline irrigation with a neti pot or spray on a daily basis to treat congestion and mucous build up. A recent study presented at a national allergy and immunology meeting showed that when patients used nasal saline irrigation on a daily basis for a year, they had 60% more acute nasal/sinus infections over the course of the year, compared to not using the nasal saline irrigation on a daily basis.
It is appropriate and most likely helpful to use nasal saline irrigation on an intermittent basis when you have a cold, or are developing a cold, to help improve clearance of already infected mucus. For this purpose it can be used for a week or 10 days and most of my patients report that it helps. I prefer the use of a neti pot, rather than a spray, since a neti pot rinses the sinuses with passive flow of the saline whereas a spray introduces an element of positive pressure.
Although the short-term use of nasal saline irrigation can be helpful and should be considered a good thing, this study shows that the daily use of nasal saline irrigation over longer periods of time might be harmful. It is possible that ongoing enhanced clearance of uninfected “good” mucous might end up making it more likely that an infection develops.
I think this is important information since the lay public and many physicians often assume that they don’t need to worry about bad side effects from a medical intervention that does not involve a “medication” but instead involves a “natural” substance, like salt water. This study shows that even “natural” therapies can have potential side effects.
One caveat: This is one study and it should be repeated to assure that the results are accurate.