 Gargling is one of the best things to do to treat a sore throat. As one of my medical mentors, Dr. Michael Clapper instructs you, take a glass of warm water, add a pinch of salt, hold the glass of salt water in your hand, open your mouth, take a deep breath, tilt your head back, slide a generous mouthful to the back of your throat, and with your mouth still open, gently breathe out through the water. Continue until the end of the breath and then, spit it out in the sink, repeat until the full glass of salt water is used. Works wonders to soothe a sore throat when you have a cold, but I never heard of gargling to prevent a cold. Though not popular in the Western world, gargling has been strongly recommended in Japan to prevent upper respiratory tract infections, such as the common cold. However, there have been no controlled trials, and it remained unresolved as to whether gargling was really effective, until this one was published in 2005. They found a significant drop in the incidence of the common cold, but not the flu, suggesting that simple plain water gargling is effective in preventing upper respiratory tract infections among healthy people. This virtually cost-free modality would appreciably benefit people both physically and economically around the world. What do they mean economically? Well, most Americans, for example, report about 2 to 3 colds a year. That actually surprised me. Between medical costs and work absenteeism, we're talking nearly $40 billion a year, the common cold. So even if you take into account the 71 seconds it took, on average, to walk to and from the sink and gargling, and multiply that by the average wage to calculate the cost of gargling in wasted time, it's still considered a cost-effective strategy. Here's the latest, a new study on whether it works in kids. Gargling for oral hygiene and the development of fever in childhood. A total of nearly 20,000 preschoolers were observed for 20 days, and just like the study for adults, gargling appears to lower the odds of illness by about a third, and gargling with green tea may work better. To note, they speculate that the fact that tap water is chlorinated may play a role, so gargling with filtered water may be less effective. But I would stay away from iodine solutions, such as betadine, since one can run into the same kind of iodine overload thyroid dysfunction you can get by eating too much kelp.