In a trial of e-cigarettes among Italian smokers with no desire to quit using tobacco at the outset, up to 13 percent of participants were not smoking regular cigarettes at all a year later.
Though the study was not billed as a smoking-cessation test, more than half of participants cut down on tobacco soon after they started using the e-cigarettes. And the percentage who quit smoking entirely by the end rivals results achieved with medications, the authors note in the journal PLOS ONE.
"I think the main message of the study is that we can use these products as an extraordinary tobacco control tool," Dr. Riccardo Polosa, the new study's senior author from the University of Catania, told Reuters Health.
"This really is the first clinical trial that's ever been reported on electronic cigarettes. There has been survey evidence and anecdotal reports, but this is the first serious study," said Dr. Michael Siegel, who studies e-cigarettes but wasn't involved in the new research.
E-cigarettes were first introduced in China in 2004. The battery-powered devices let users inhale nicotine-infused vapors, which don't contain the harmful tar and carbon monoxide in tobacco smoke.
While past studies have looked at the use of e-cigarettes, the new study is the first to follow hundreds of smokers for an entire year. It did not, however, compare the devices to traditional nicotine replacement therapies, such as gum or patches.
Siegel, a professor at the Boston University School of Public Health, said he would expect about 2 percent of the participants to quit within a year if they weren't involved in a study.
However, Polosa's team also found that between 9 and 12 percent of people in each of the nicotine-cartridge groups had reduced the amount they smoked by at least half.
"The study is very positive in that it shows if you smoke even a low- or medium-strength e-cigarette, you can get some increased quitting and decreased smoking," Dr. Murray Laugesen, a tobacco and nicotine researcher who was not involved with the new study, told Reuters Health.
"It also has to be acknowledged that these are good results in people who had no intention of quitting," said Laugesen, a public health medicine specialist at Health New Zealand Ltd in Christchurch. He is also involved in an e-cigarette clinical trial and hopes to present the results in September.
Siegel told Reuters Health that what's attractive about e-cigarettes is they can not only provide the nicotine that smokers crave without other harmful substances, they allow people to mimic their traditional smoking behavior.
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