A study published this week has found that older teenagers who experiment with e-cigarettes are six times more likely to try regular cigarettes within the next two years, even when taking controlling for considerations related to ethnicity, gender, parental education, and grade.
Scientists said they were concerned that young people who try e-cigarettes may graduate to other types of tobacco products such as traditional cigarettes, which are in all probability more dangerous.
The study was authored by the University of Southern California post-doctoral researcher Jessica Barrington-Trimis and was published in the journal Pediatrics on Monday, reports Andrew M. Seaman for Reuters.
Using e-cigarettes is called vaping because the electronic devices vaporize a fluid typically made up of nicotine and a flavoring.
Barrington-Trimis and her team studied roughly 300 high school students in California in 2014, and half the teens said they had at least tried e-cigarettes.
In a follow-up survey in 2015, approximately 40% of those young people who had tried e-cigarettes in the previous year had tried regular cigarettes. Of the kids who had not tried an e-cigarette in the prior year's survey, 11% had tried a traditional cigarette.
When researchers looked at young people who stated on the first questionnaire that they had no desire to smoke, the odds of moving from e-cigarettes to actual cigarettes by the next year was ten times greater than for the students who never vaped.
This increased chance of students dabbling even when they had committed to not smoking, says Barrington-Trimis, "suggests this is not occurring among kids who intended to smoke anyway." The participants were juniors and seniors who were age 18 by the time the second survey was given.
But Dr. Michael Siegel, a professor at the Boston University School of Public Health, is a supporter of e-cigarettes as a choice to assist smokers from smoking traditional cigarettes. He said the study did not prove that using e-cigarette has encouraged teens to begin smoking conventional cigarettes.
"What's probably happening is these kids did not become regular vapers, (and) they turned to smoking," Siegel said. "If they turned into regular vapers, they wouldn't have turned to smoking."
Still, because of the question of whether e-cigarettes are a gateway to tobacco smoking during the last few years, the US Food and Drug Administration has banned the sale of e-cigarettes to minors beginning in mid-summer, says HealthDay's Randy Dotinga.
"We can't definitively conclude the e-cigarettes cause kids to smoke cigarettes," Barrington-Trimis said. However, "those who had used e-cigarettes at baseline were substantially more likely to begin smoking cigarettes."
Peter Hajek, Director of Tobacco Research at the Wolfson Institute of Preventive Medicine at Queen Mary, University of London, also disagreed with the results of the study.
"The authors misinterpret their findings," Hajek said. "Like several previous studies of this type, this one just shows that people who try things, try things."
Hajek adds that there are other findings which show that, in general, smoking by adolescents is declining at the same time that e-cigarette use increases.
Earlier this year, the CDC found that advertisers for e-cigarettes were appealing to teenagers using tactics that were the same as regular cigarette companies had been told not to use. The ads feature sex, independence, and rebellion and are just like the advertising that got teens of yesteryear to smoke traditional cigarettes, according to Gretel Kauffman of The Christian Science Monitor.