REVIEW OF: Goldenson NI et al, JAMA Pediatrics 2017;171(12):1192–1199

Considering them less lethal than traditional cigarettes, many adolescents are turning to electronic cigarettes as a “safer” alternative to tobacco products. In 2016, 11% of U.S. 10th graders reported using e-cigarettes for vaping. Adolescents who vape can inhale nicotine concentrations ranging from 0 mg/ml to 25 mg/ml, compared to roughly 10 mg of nicotine in a cigarette. Since nicotine’s impact on a developing nervous system is greatest during early adolescence, exposure to high nicotine levels during this period increases the risk of nicotine dependence.

The current study, conducted by researchers at the University of Southern California, looked at vaping habits of 10th graders in Los Angeles to determine if there is an association between baseline nicotine concentrations vaped, and the resulting frequency and intensity of eventual tobacco cigarette smoking at 6 months follow-up. All data were collected using questionnaires. Students who used e-cigarettes in the previous 30 days provided information on the concentration of nicotine vaped, the number of days vaped, the intensity of vaping, the number of days smoking tobacco cigarettes, and the number of tobacco cigarettes smoked. All measurements were collected at baseline and follow-up. Nicotine concentrations were grouped by none (0 mg/ml), low (1–5 mg/ml), medium (6–17 mg/ml), and high (≥ 18 mg/ml).

Overall, 3,252 students completed the initial assessment. The final sample on those who took the second survey included 181 students who vaped, 96 (53%) of whom were boys. At the 6-month follow-up, the 21 adolescents who used high-nicotine e-cigarettes were smoking 7 times as many tobacco cigarettes per day as those who used non-nicotine e-cigarettes. On average, the high-nicotine vapers smoked 2.5 cigarettes/day, an increase from 1.9 cigarettes/day at baseline, compared to 0.2 cigarettes/day in the non-nicotine vapers. Adolescents who used medium- or low-nicotine e-cigarettes did not have an increase in daily smoking but did have more vaping episodes per day and more puffs per episode.

CATR’s Take
The results of this study provide evidence that use of e-cigarettes with high nicotine concentrations can lead adolescents to smoke tobacco cigarettes. E-cigarettes are popular among adolescents. However, nicotine remains highly addictive regardless of its formulation. Exposure to high levels of nicotine concentration during early adolescence increases the risk of addiction and negatively impacts the development of brain circuits controlling attention, complex thinking, and impulsivity. This study helps to challenge the perception that vaping nicotine is safe and reinforces that we should continue to advise adolescents to avoid nicotine in any form.