“Recreational e-cigarette use is becoming increasingly popular among teens who have never smoked tobacco," Adam M. Leventhal, lead author of the study, said in a news release. "Adolescents who enjoy the experience of inhaling nicotine via e-cigarettes could be more apt to experiment with other nicotine products, including smokeable tobacco.”
E-cigarettes are battery-powered devices that deliver nicotine through a vapor by heating a solution of propylene glycol or vegetable glycerin, flavoring and other additives.
The study, published in the Journal of the American Medical Association, followed a group of about 2,500 Los Angeles ninth graders at 10 public high schools and surveyed them about their tobacco and e-cigarette use three times in a year. At the start of the study, 222 of the students had used e-cigs, but not traditional cigarettes, and 2,308 had smoked neither.
The study found that e-cigarette users were almost four times more likely than those who had never tried them to have smoked combustible tobaccos, such as cigarettes, cigars and hookahs, within six months (30.7 percent vs 8.1 percent, respectively) and more than twice as likely in 12 months (25.2 percent vs 9.3 percent, respectively).
The findings are important because teen e-cigarette use tripled between 2013 to 2014, surpassing teen use of all tobacco products. Nationwide, 13.4 percent of high-school students reported smoking e-cigs and 3.9 percent of middle-school students in 2014, according to a report by the Centers for Disease Control and Prevention.
“While teen tobacco use has fallen in recent years, this study confirms that we should continue to vigilantly watch teen smoking patterns,” Nora D. Volkow, director of the National Institute on Drug Abuse, said in the press release. “Parents and teens should recognize that although e-cigarettes might not have the same carcinogenic effects of regular cigarettes, they do carry a risk of addiction.”
The researchers acknowledge that their study doesn't prove that e-cigarettes cause teens to start smoking cigarettes, but they say that it is a possibility, and further research is needed to confirm their findings.
In a separate JAMA editorial, Nancy A. Rigotti, an author of the study, calls for prompt marketing regulations by the U.S. Food and Drug Administration to stop e-cigarettes from being marketed in ways that appeal to children and adolescents. "A rational approach is to extend to e-cigarettes the same sales, marketing, and use restrictions that apply to combustible cigarettes," she writes.
The FDA has been working on regulations for e-cigarettes since April 2014.