The study, published in the Journal of the American Medical Association, looked at more than 3,000 teens in 10 Los Angeles County public schools who “vaped” frequently and found they were more than twice as likely to start smoking “on about a weekly basis” and twice as likely to smoke more cigarettes on days when they do smoke, HealthDay reports.
“The more you vape, the more likely in the future you’re going to be smoking. You’re going to be smoking more frequently and you’re going to smoke more cigarettes per day on your smoking days,” lead researcher Adam Leventhal told HealthDay.
Leventhal is an associate professor of preventive medicine and psychology at the University of Southern California Keck School of Medicine in Los Angeles.
In Kentucky last year, 41.7 percent of high-school students said they have used an electronic vapor product and 23.4 percent said they were currently using one, according to the Youth Risk Behavior Study. Both of these numbers are similar to the national rates of 44.9 percent and 24.1 percent, respectively.
This study, like others, established an association between smoking and vaping, not cause and effect, HealthDay reports. However, the e-cigarette industry criticized the study’s definition of “frequent” vaping or smoking as three days or more each month.
“Why? Because despite having a sample size of over 3,000, the authors were only able to identify a fraction of students who had progressed onto any cigarette smoking, let alone actual frequent or heavy smoking,” said Gregory Conley, president of the American Vaping Association,
The study surveyed 10th graders in the Los Angeles high schools during fall 2014 and six months later. About 95 percent of the students in the study said they were non-smokers, and about 98.5 percent said they’d never vaped.
However, HealthDay reports: “The kids who did vape were more likely to try cigarette smoking, and more frequent vaping was associated with more frequent and heavier smoking, Leventhal said.”
Leventhal suggested this could be because teens will first get hooked on the nicotine in the e-cigarettes and then turn to tobacco for a “stronger fix” or that e-cigs make them familiar with smoking, making it easier to make the switch to traditional cigarettes.
Dr. Norman Edelman, the American Lung Association‘s senior scientific adviser, agreed that nicotine in e-cigarettes could lead teens to smoke traditional cigarettes and called for stricter regulations of e-cigs, including the ban of any marketing targeted at teens.
Conley countered that “the rise in vaping experimentation has fueled record-breaking declines in teen smoking,” reports HealthDay. He added: “It would be public health malpractice to use studies with poorly defined parameters, such as this one, as an excuse to deny adults access to these far safer products.”