Going backward: The renormalization of nicotine use
We agree with the published opinion by McKee and Capewell on the Public Health England’s (PHE) report . The ongoing debate, however, seems to overlook e-cigarettes possible hazards by diverting the attention to potential benefit in terms of harm reduction among dual users, albeit arguable . Therefore, it is essential to focus on its impact on naïve users; especially adolescents, which we intend to address here.
In the United States, e-cigarettes emergence permitted television and radio marketing of nicotine products once again, after the complete ban on tobacco products advertisement since the 1970s . In 2014, around 18.3 million adolescents in the United States were exposed to at least one method of e-cigarette marketing method , which represents 68.9% of middle and high school students who participated in the 2014 National Youth Tobacco Survey (NYTS). More than one third of them (36.5%) were exposed to marketing messages via television. In the same survey, it was reported that e-cigarette is the leading tobacco product in use by American adolescents (lifetime and current use) . In an online survey among 519 adult smokers and recent quitters, it was suggested that e-cigarette users were significantly more likely to have the urge to smoke conventional cigarettes compared to non-users after viewing e-cigarettes TV advertisement (83% and 72%, respectively) .
Moreover, a study among school children in Los Angeles revealed that non-smokers who used e-cigarettes were more likely to use combustible tobacco products in subsequent longitudinal follow up compared to non-users . E-cigarettes supply the same addictive substance, i.e. nicotine, as in other tobacco products. Nicotine has been described as a gateway medication, not just for smoking other tobacco products, but also for alcohol and substance use [8 &9], which underscores a new paradigm of possible adverse outcomes that might be witnessed with the increasing e-cigarette use.
Furthermore, findings from a study in Utah suggest that state laws restricting sale to minors was inadequate to prevent the increasing prevalence of e-cigarette use among minors . Noteworthy, the expanding use of e-cigarettes among adolescents is not confined to the USA as similar trends were observed in other countries (e.g. ), but data related to adolescents’ use, in general, are limited.
It can be concluded from the previous studies that e-cigarettes might lead to a rebound increase in other tobacco products use via two possible mechanisms. The first is a direct effect via the nicotine gateway mechanism [7-9]. The second, however, is an indirect one through its marketing messages [4-6], renormalization of smoking within public spaces, and societies ; while sale restriction alone might be ineffective in controlling adolescents’ e-cigarette increasing use [10& 13-14]. Therefore, we join the view to require regulating e-cigarette as a medication, if it has a role in smoking cessation [1&15]. This might be a reliable way to control naïve users’ (especially adolescents) access to e-cigarettes, until such reliable evidence on its safety is available.
 McKee M, Capewell S. (2015) Evidence about electronic cigarettes: a foundation built on rock or sand? BMJ 2015;351:h4863
 Auf R. (2014) Electronic cigarettes and smoking cessation: a quandary? Lancet. Feb 1;383(9915):408. doi: 10.1016/S0140-6736(14)60144-6.
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 Centers for Disease Control and Prevention. (2015) Tobacco Use Among Middle and High School Students — United States, 2011–2014. MMWR, April 17, 2015 / 64(14);381-385
 Centers for Disease Control and Prevention. (2016) Vital Signs: Exposure to Electronic Cigarette Advertising Among Middle School and High School Students — United States, 2014. MMWR, January 8, 2016 / 64(52);1403-8.
 Kim AE, Lee YO, Shafer P, Nonnemaker J, Makarenko O. (2015). Adult smokers' receptivity to a television advert for electronic nicotine delivery systems. Tob Control. 2015 Mar; 24(2):132-5.
 Leventhal AM, Strong DR, Kirkpatrick MG, Unger JB3, Sussman S, Riggs NR, Stone MD, Khoddam R, Samet JM, Audrain-McGovern J. (2015) Association of Electronic Cigarette UseWith Initiation of Combustible Tobacco Product Smoking in Early Adolescence. JAMA. Aug 18;314(7):700-7. doi: 10.1001/jama.2015.8950.
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 Kandel ER, Kandel DB. (2014). Shattuck Lecture. molecular basis for nicotine as a gateway drug. N Engl J Med. 2014 Sep 4;371(10):932-43. doi: 10.1056/NEJMsa1405092.
 Utah Department of Health. Utah health status update: electronic cigarette use among Utah students (grades 8, 10, and 12) and adults. Updated December 2013. http://tobacco.ucsf.edu/e-cigarette-use-among-kids-skyrocketing-utah-lev...
 Lee S, Grana RA, Glantz SA. (2013) Electronic-cigarette use among Korean adolescents: a cross-sectional study of market penetration, dual use, and relationship to quit attempts and former smoking. J Adolesc Health. doi: 10.1016/j. jadohealth.2013.11.003.
 Fairchild AL, Bayer R & Colgrove J. (2014). The renormalization of smoking? E-cigarettes and the tobacco "endgame". N Engl J Med. 2014 Jan 23;370(4):293-5. doi: 10.1056/NEJMp1313940. Epub 2013 Dec 18.
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Competing interests: No competing interests