This may be the first substantial evidence that e-cigs could help people quit smoking
Public health experts are divided on the question, but a new study is the first of its kind to suggest that for some people, the devices could help more than they hurt.
The paper, published in the journal Addictive Behaviors, looks at how patterns of quitting smoking have changed across America since e-cigarettes - devices that vaporize liquid nicotine rather than burning tobacco and creating tar - were introduced in 2010.
Researchers at Columbia University and Rutgers University looked at two years of data from an annual, nationwide household survey and homed in on two groups of people: current smokers and former smokers who quit during or before 2010, the year e-cigarettes were introduced.
Among the roughly 15,500 adults the researchers looked at, those who said they used e-cigs daily were far more likely to have quit regular cigarettes than the people who said they'd never tried e-cigs. In fact, over half of daily e-cigarette users had quit smoking in the past five years, compared to just 28% of those who had never tried them.
Looked at another way, the single strongest predictor of someone in the survey having quit smoking was daily e-cigarette use.
"Our findings suggest that frequent e-cigarette use may play an important role in cessation or relapse prevention for some smokers," Daniel Giovenco, an assistant professor of sociomedical sciences at Columbia University's Mailman School of Public Health and the lead study author, said in a statement.
The study builds on previous observational research suggesting that e-cigs could help smokers quit. A large study of 160,000 people spanning more than 15 years and published in the journal BMJ in July last year suggested that smokers who used e-cigarettes not only tried to stop smoking more frequently but also succeeded (for at least a few months) more often than those who didn't use them.
Still, these studies are observational and have limitations. Because observational studies look at groups of people and their behavior over time, it's hard to say for sure that other conflicting factors aren't influencing the outcomes they examine. It's also worth pointing out that the study didn't address whether e-cigs might appeal to people who would otherwise not smoke or vape at all.
Plus, e-cigs aren't risk-free: some of the devices have been found to contain ingredients like diethylene glycol (used in antifreeze) as well as formaldehyde, both of which have been linked with cancer. Studies also suggest that frequent e-cig use could raise your risk of heart disease.
This is why researchers emphasize that more studies are needed - preferably studies that explore details about the kinds of e-cig devices people are using as well as why and how frequently they use them.
"Uncovering patterns of use at the population level is a critical first step in determining if [e-cigarettes] may present any benefits to public health," said Giovenco.