THURSDAY, Sept. 25, 2014 (HealthDay News) -- New research suggests that e-cigarette use by American adults who don't smoke has stalled.
Among those who have never lit up, there was virtually no change in the percentage who had ever tried e-cigarettes between 2010 and 2013, going from 1.3 percent to 1.2 percent.
But the trend traveled the other way for current and former smokers, the researchers from the U.S. Centers for Disease Control and Prevention (CDC) reported. They found the number of current and former smokers who have used electronic cigarettes at least once increased nearly fourfold from 2010 to 2013.
Current smokers who had ever used e-cigarettes rose from 9.8 percent in 2010 to 36.5 percent in 2013, while that percentage jumped from 2.5 percent to 9.6 percent for former smokers between 2010 and 2013.
"The long-term public health impact of these products is uncertain," study author Brian King told the Associated Press, although he noted the statistics on nonsmokers struck "a positive note."
The findings came from an annual survey of thousands of adults aged 18 and older. The survey has been the government's sole source of data on e-cigarette use since the products first hit the U.S. market in 2006, the wire service reported.
E-cigarettes look much like their tobacco-based cousins, but they are battery-powered devices that release a vapor that typically contains nicotine and is often flavored. Believed to be a less dangerous alternative to regular cigarettes, they are often touted as a way to help smokers quit, according to the AP.
Judging from the findings of this latest study, that belief might be faulty, the researchers noted.
The fact that the rise in e-cigarette use is being driven by current and former smokers suggests that many smokers believe e-cigarettes can help them quit, despite a lack of firm evidence, the CDC said in a news release.
Roughly 75 percent of current e-cigarette users said they also smoked regular cigarettes and that figure didn't changed much in the four years of the survey, the AP reported.
That finding "raises serious questions about whether this product is really helping people quit," Matthew Myers, president of the Campaign for Tobacco-Free Kids, told the wire service.
E-cigarettes are not currently regulated by the government, although the FDA is proposing to do just that.
The study also found that adults' awareness of e-cigarettes doubled between 2010 to 2013, from nearly 41 percent to nearly 80 percent, and that increased advertising likely fueled that awareness.
From 2011 to 2012, e-cigarette makers boosted their annual advertising spending from $6.4 million to $18.3 million, the CDC noted.
The study was published online recently in the journal Nicotine and Tobacco Research.
The U.S. Food and Drug Administration has more about e-cigarettes.