Does Vaping Lead to Smoking?

Non-smoking teens who try electronic cigarettes are more likely to later try smoking combustible tobacco, a research team reports in JAMA.

But it is not clear from their new study whether these teens were already likely to become tobacco smokers and whether their "vaping" of e-cigarettes served as a gateway or whether it turned them into nicotine addicts.

Adam Leventhal, PhD, and colleagues at the University of Southern California’s Keck School of Medicine’s department of preventive medicine and colleagues looked at whether e-cigarette use among 14-year-old high school students in Los Angeles was associated with starting smoking within a year of trying the vapor-emitting products.

They surveyed a school-based cohort in the fall of 2013, again six months later, and a third time at 12 months.

“Past six-month use of any combustible tobacco product was more frequent in baseline e-cigarette ever users (a total of 22 students) than those who never tried e-cigarettes (2,308 students) at the first follow-up,” they wrote.

At the 12-month followup the difference was even more evident, with 25.2% of e-cigarette users going on to smoke vs. 9.3% of those who had not tried e-cigarettes.

The team’s definition of combustible tobacco use included smoking cigarettes, cigars, and hookah pipes.

Commenting on their findings, the authors said there were several possible explanations for the association between using e-cigarettes and smoking tobacco.

One is that these teenagers had risk factors that made them more likely to become tobacco smokers but tried e-cigarettes first because they thought they were safer.

That would mean that “onset of e-cigarette use relative to combustible tobacco use may not be determined by a causal sequence.”

Or these teens were not necessarily on a track to become tobacco smokers, but could have been influenced by youth-targeted marketing such as ads stressing the “attractive” flavors of e-cigarettes.

Lack of restrictions on e-cigarette sales to minors could also be a factor.

“It is also plausible that exposure to e-cigarettes, which have evolved to become effective nicotine delivery devices, may play a role in risk of smoking initiation,” they note.

Manufacturers have focused on technology aimed at getting nicotine into the e-cigarette vapor quickly and adolescent brains are likely more sensitive to the drug’s effect, they said, but seeing whether that resulted in addiction was a question beyond the goals of the study.

Commenting on the report, the American College of Cardiology’s President Kim Allan Williams, MD, said,

“Knowing the long-term consequences of tobacco use, it is mind boggling to think that anyone would assume e-cigarette use is acceptable among children, when for many it can function as an entry drug.”

Williams called on regulators to restrict sales and advertising of e-cigarettes to minors.

“This research provides one more piece of evidence that what common sense tells us is likely true: inhaling an addictive chemical is not good for anyone,” Williams said.