Steam cure for colds: full of hot air?

Steam cure for colds: Full of hot air?

In 1987, Israeli researchers reported that three-fourths of the cold sufferers they had studied showed symptomatic improvement the day after inhaling hot steam. "The potential impact was mind-boggling," recalls pediatrician Michael L. Macknin. "To think that with two 20-minute treatments you could cure the common cold...."

To see if Americans might likewise benefit from the steam treatment, Macknin and his associates at the Cleveland Clinic have now repeated the experiment with snuffy-nosed volunteers from Cleveland. Each of the 66 patients received two 20-minute treatments, 60 to 90 minutes apart, consisting of air inhaled from a pair of exhaust nozzles held an inch from the nose. Roughly half the group inhaled dry, room-temperature air; the others inhaled hot, humidified air. Neither subgroup knew which was the supposed cure.

To the researchers' surprise, reports from the volunteers one week later revealed that sneezing, sniffling and stuffiness were 33 percent more likely to persist in steam inhalers than in their unsteamed counterparts, who--like most people after a week of cold symptoms--were essentially cured. A machine measuring nasal congestion showed an 11 percent improvement in the unsteamed group and a 6 percent worsening in the steam-treated snifflers, Macknin and his colleagues report in the Aug. 22/29 JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION. "If steam treatment works, we couldn't show it," says Macknin.

The study dampens the hopes of steam-cure enthusiasts while also raising concerns about the treatment's potentially aggravating effects on virally besieged nasal membranes, Macknin says.

The notion that colds improve with steam treatment may have originated with the traditional steaming cup of chicken soup, say some cold experts. In recent decades, however, the practice has acquired a scientific rationale. Rhinoviruses, which cause more than one-quarter of all colds, grow best at 33[degrees]C -- a temperature conveniently provided by the human nose, explains Macknin. According to the steam theory, increasing the intransal temperature kills the rhinoviruses. "but nobody has demonstrated convincingly in people that you can kill the virus in this manner," he says.