Puffing on a battery-powered, electronic cigarette to satisfy nicotine cravings could help longtime smokers quit their tobacco addiction. The evidence supporting that claim has been thin in the past, but researchers have now reported that adults in England who used the devices were 60% more likely to remain smoke-free than those who turned to nicotine patches or went cold turkey. Some public health researchers, though, still worry that’s not enough to cancel out the negative effects of e-cigarettes, which might keep other smokers hooked on nicotine or prevent them from seeking out more effective ways to quit.
“This is an important study because, until now, the data on quitting smoking with e-cigarettes has been mostly anecdotal,” says Neal Benowitz, a physician at the University of California, San Francisco (UCSF), who studies tobacco addiction and was not involved in the work.
E-cigarettes produce a nicotine-rich vapor that’s free of many of the toxins and carcinogens that make tobacco cigarettes so unhealthy. Their popularity has skyrocketed since they hit the market in the early 2000s; a 2012 survey found that 30% of adult smokers in the United States had tried e-cigarettes. But studies attempting to establish both the risks and benefits of the devices have had varied conclusions.
One recent review of the scientific literature, which included Benowitz as an author, reported that smokers who used e-cigarettes were less likely to quit smoking  than those who didn’t use the devices. The results were based on broad surveys of all smokers, however, not just those attempting to quit. Another paper concluded that e-cigarettes are about as effective as nicotine patches  at helping people stop smoking.
Since 2006, researchers in England have run an ongoing surveillance program, in conjunction with the government’s research bureau, called the Smoking Toolkit Study. Every month, they survey a new sample of 1800 random adults about their smoking behavior. In 2009, they began collecting specific data on e-cigarette use. Now, the scientists have analyzed answers from the more than 6000 respondents who, between 2009 and 2014, reported attempting to quit smoking without the help of counseling or prescription medication.
Twenty percent of people who reported using only e-cigarettes to help them quit —at any point in the year before they were surveyed—remained smoke-free at the time of the survey, the team reports online today in the journal Addiction. Among those who had tried quitting with no aid, 15% still weren’t smoking, and among those who used nicotine patches, 10% remained off cigarettes. Once other variables were taken into consideration—including age, previous quit attempts, and packs per day smoked—the increased chance of remaining smoke-free when using e-cigarettes to quit was about 60%.
“With an e-cigarette, there’s enough simulation of the smoking experience that people feel more rewarded for doing it,” says psychologist Robert West of University College London, an author of the new study. “That positive reward keeps them doing it longer.”
But the rate of people who successfully quit using e-cigarettes doesn’t necessarily tell the whole story. A combination of counseling and prescription medication is still the most effective way for smokers to quit, West says, although numbers on that method weren’t reported in the latest study. It’s unclear whether people who would be quitting with these more effective methods are instead turning to e-cigarettes—which would lower the overall quit rate among smokers. “This is just one piece of the jigsaw puzzle,” he says.
Tobacco control researcher Stanton Glantz of UCSF says that caveat is a big one. E-cigarettes could be changing the number of people trying to quit smoking at all, he points out. Previous studies have showed a high rate of e-cigarette use among smokers not intending to quit, who instead using the devices to help sustain their nicotine habit. “Yes, there are people who have successfully used e-cigarettes to quit smoking, but the statistics show that for every person like that, there’s more than one other person who has not tried to quit at all because of the very existence of e-cigarettes.”
The new study also doesn’t contain data on how long users continue using e-cigarettes after they quit tobacco—or their long-term likelihood of returning to smoking. West says future analyses of the Smoking Toolkit Study data hope to answer these questions.
Benowitz says that although his standard recommendation to patients is to try medications and counseling to quit smoking, the new results suggest that e-cigarettes could be helpful. “If someone wants to use e-cigarettes, I certainly wouldn’t discourage them.” But prescribing e-cigarettes, he adds, when more than 400 products are on the market, with varying levels of nicotine and side effects, is a different matter. More research—or regulation—is needed before doctors can take that step, he says.