Breaking Research on the Risks of E-Cigarettes

It’s undeniable how quickly e-cigarettes are growing, especially among teenagers where use of electronic devices that deliver nicotine has increased dramatically over the past 5 years. Some research suggests that it has increased more than 10 times from 2011 – 2014 (Johnston et al., 2015). However, research has been limited in examining how the use of e-cigarettes in adolescence relates to use of regular combustible cigarettes later.

New research out of the Health, Emotion, and Addiction Laboratory at the University of Southern California, led by Dr. Adam Leventhal and a group of colleagues that I had the great fortune of also working on, has helped clarify the association. A just released article published in the Journal of the American Medical Association examined whether adolescents who had tried e-cigarettes prior to entering high school (but not combustible cigarrettes) were at greater risk for initiating use of three combustible tobacco products (i.e. cigarettes, cigars, and hookah) during the first year of high school. Dr. Leventhal states that,

“Recreational e-cigarette use is becoming increasingly popular among teens who have never smoked tobacco.  Adolescents who enjoy the experience of inhaling nicotine via e-cigarettes could be more apt to experiment with other nicotine products, including smokeable tobacco.”

In this study, adolescents were given surveys at the beginning of high school (Fall of 9th grade) and again in the spring semester of 9th grade as well as the fall of 10th grade. Results indicated that adolescents who had used e-cigarettes at some point in their life prior to the first survey at the beginning of 9th grade were approximately 4 times more likely to report smoking combustible cigarettes later in 9th grade and into 10th grade. Even after adjusting for demographic factors of the adolescents and environmental risk factors that may be related to smoking, e-cigarette users were still nearly three times more likely to report initiating combustible cigarette smoking at the follow-up time points. These results are critical in helping us understand the risks associated with e-cigarettes.

Dr. Adam Leventhal provides a cautionary note stating that,

“While we cannot conclude that e-cigarette use directly leads to smoking, this research raises concerns that recent increases in youth e-cigarette use could ultimately perpetuate the epidemic of smoking-related illness.” 

As with any study, there are limitations to this research. This study did not examine progression of tobacco smoking; thus, it is important for future work to examine whether e-cigarette use is associated with progression to regular smoking as well. Also, this article does not speak to the relative harmfulness of e-cigarettes versus combustible cigarettes. Instead, this article provides a context to look at the relationship between the two. Furthermore, this study does not imply causality where e-cigarettes causes combustible cigarette use. Rather, results point to a strong association between the two and future studies should continue to examine this association to see if it found in other populations. However, despite these limitations, this study is a critical piece of the puzzle to understanding risks associated with tobacco smoking.article continues after advertisement

Here is the citation to the recent article: Leventhal, A.M., Strong, D.R., Kirkpatrick, M.G., Unger, J.B., Sussman, S., Riggs, N.R., Stone, M.D., Khoddam, R., Samet, J.M., Audrain-McGovern, J. (in press). Association of electronic cigarette use with initiation of combustible tobacco product smoking in early adolescence.  JAMA.