Does Vaping Help Smokers Quit?

"We don't have the definitive study on that," Warner says. "My reading of the evidence is that it is quite convincing that e-cigarettes are helping some people quit smoking."

Caren Kagan Evans, 56, of Washington DC, is one of those people. She started smoking when she was 13-years-old. Over the years, Evans tried to quit by using the nicotine patch, gum, and even hypnosis.

Vaping worked in a month, and she's been off cigarettes for more than two years. "I'm breathing, sleeping, and eating much better since I started vaping. My 'smoker's laugh' went away, and I no longer smell like an ashtray."

But Evans' story is the exception, not the rule.

"If there was good evidence that people were using e-cigarettes just to quit smoking, there would be wide support," Benowitz says. "The problem is most of the e-cigarette use in the U.S. is dual use with cigarettes." People use e-cigs in places or situations where they can't smoke, like in a restaurant, but continue lighting up when they can, he explains.

Sward points out that according to the FDA, there's no evidence any e-cigarette is safe and effective at helping smokers quit. She suggests talking to your doctor about medications and other strategies that are proven stop-smoking tools.

The American Heart Association says e-cigs should only be used as a last resort way to quit.