THE CASE FOR OR AGAINST E-CIGARETTES: WHAT THE SCIENTIFIC RESEARCH SAYS

Issue 23, Summer/Fall 2014

e-cigars

Electronic cigarettes are inhalant devices that heat liquid nicotine and emit vapor – often a combination of water, other chemicals, and propylene glycol, a substance approved by the FDA for other purposes. They hit European and American markets in 2006 and 2007, and their popularity has been propelled by international trends favoring smoke-free environments. Sales reportedly have reached $650 million a year in Europe and were estimated to reach $1.7 billion in the US in 2013 (compared to $80 billion for cigarettes).

Although research on e-cigarettes is not extensive, a picture is beginning to emerge. Surveys suggest that the vast majority of those who use e-cigarettes treat them as smoking-cessation aides and self-report that they have been key to quitting.1 Data also indicate that e-cigarettes help to reduce tobacco cigarette consumption. A 2011 survey, based on a cohort of first-time e-cigarette purchasers, found that 66.8 percent reported reducing the number of cigarettes they smoked per day and 49.3 percent reported reducing nicotine use. After six months, 31 percent of e-cigarette users reported not smoking. These results compare favorably with nicotine replacement therapies (NRTs) like the patch and nicotine gum; pooled data on NRTs show that 17.8 percent of participants are no longer smoking at the six-month mark.2Interestingly, a randomized controlled trial found that even e-cigarettes without nicotine were effective both in achieving a reduction of tobacco cigarette consumption and longer term abstinence, suggesting that “factors such as the rituals associated with cigarette handling and manipulation may also play an important role.”3

A randomized controlled trial conducted in New Zealand and published in 2013 found that after six months 7.3 percent of those using e-cigarettes had not started smoking again compared to 5.8 percent of those assigned to the patch and 4.1 percent of the participants who had used e-cigarettes without nicotine. Cessation was verified biochemically. Because overall cessation was lower than expected, however, the study lacked the statistical power to be considered conclusive.4 Yet a study amongst Korean youth found very different results: though adolescents who had attempted to quit were more likely to use e-cigarettes, they were no more likely to have quit.5

e-cigars

A 2010 study has, predictably, shown that e-cigarettes suppress nicotine cravings less effectively than tobacco cigarettes.6 Some tobacco control advocates worry that they simply deliver an insufficient amount of nicotine to ultimately prove effective for cessation. Nevertheless, the tobacco control community has embraced FDA approved treatments—NRTs and the drugs bupropion and varenicline (Chantix®)—that have relatively low success rates.

In a commentary published earlier this year in the Journal of the American Medical Association, smoking cessation experts Andrea Smith and Simon Chapman of the University of Sydney said that smoking cessation drugs fail most of those who try them. “Sadly, it remains the case that by far the most common outcome at 6 to 12 months after using such medication in real world settings is continuing smoking. … Few, if any, other drugs with such records would ever be prescribed,” they wrote.

Amongst smokers not intending to quit, e-cigarettes—both with and without nicotine—substantially reduced consumption in a randomized controlled trial, not only resulting in decreased cigarette consumption but also in “enduring tobacco abstinence.”3 In a second study, the authors reported in 2013 that after 24 months, 12.5 percent of smokers remained abstinent. Another 27.5 percent reduced their tobacco cigarette consumption by 50 percent.7 Although it had a high dropout rate (42 percent), making the findings questionable, a third study has come to the same conclusion.8 In contrast, those who used e-cigarettes showed a reduction in cigarettes smoked per day in a study published in 2013 that followed users in the UK, Canada, Australia, and the US, though e-cigarette users were no more likely to have quit than non-users.9

Users widely perceive e-cigarettes to be less toxic. While the FDA has found trace elements of carcinogens, levels are comparable to those found in nicotine replacement therapies. Results from a laboratory study released in 2013 found that that while e-cigarettes do contain contaminants, the levels range from 9 and 450 times lower than in tobacco cigarette smoke. These are comparable with the trace amounts of toxic or carcinogenic substances found in medicinal nicotine inhalers.10

A prominent anti-tobacco advocate, Stanton Glantz, has warned of the need to “protect people from secondhand emissions.”11 While one laboratory study indicates that passive “vaping,” as smoking an e-cigarette is commonly known, are releasing volatile organic compounds and ultrafine particles into the indoor environment, it noted that the actual health impact is unknown and should remain a chief concern.12 A recent 2014 study concluded that e-cigarettes are a source of second hand exposure to nicotine but not to toxins. Nevertheless, bystanders are exposed to 10 times less nicotine exposure from e-cigarettes compared to tobacco cigarettes.

There are a number of interesting points of agreement among proponents and skeptics of e-cigarettes.

e-cigars

First, all agree that regulation to ensure the quality of e-cigarettes should be uniform. Laboratory analyses have found sometimes wide variation across brands, in the level of carcinogens, the presence of contaminants, the presence of contaminants, and the quality of nicotine.

Second, proponents and detractors of e-cigarettes tend to agree that— considered only at the individual level—e-cigarettes are a safer alternative to tobacco cigarette consumption. The main concern is how e-cigarettes might shape tobacco use patterns at the population level. Proponents stress the evidence base that we have reviewed. Skeptics remain worried that e-cigarettes will become “dual use” products. That is, smokers will use e-cigarettes, but will not reduce their smoking or quit, will use them for temporary cessation only, or will use them to perpetuate addiction by vaping in places where smoking is prohibited. There are also worries that e-cigarettes could serve as a gateway to smoking for those who had never used tobacco products, particularly youth.

The Centers for Disease Control and Prevention (CDC) noted with alarm that between 2011 and 2012, middle and high school student experimentation with e-cigarettes significantly increased. Nine out of 10 of these experimenting youth were already current smokers, however. During the same period, although it was not statistically significant, the percentage of middle and high school students using cigarettes and cigars decreased.

Data from the Korean Youth Risk Behavior Web-Based Survey showed similar patterns: e-cigarette users were not only more likely to be current smokers, but heavier smokers.13

Perhaps most troubling to public health officials is that e-cigarettes will "renormalize" smoking, subverting the cultural shift that has occurred over the past 50 years, transforming what has become a perverse habit into a pervasive social behavior. In other words, the fear is that e-cigarettes will allow for reentry of the tobacco cigarette into public view. This would unravel the gains created by smoke-free indoor and, in some scientifically-unwarranted instances, outdoor environments.

Careful epidemiological studies will be needed to determine whether the individual gains from e-cigarettes will be counteracted by population-level harms. For policy makers the challenge is how to act in the face of uncertainty. Just how contested the data and its interpretation may remain is underscored by a recent clash in The New York Times between longtime anti-smoking researcher Stanton Glantz, of the University of California San Francisco, and David Abrams, executive director of The Schroeder Institute for Tobacco Research and Policy Studies at the Legacy Foundation. Glantz concludes from his recent analysis of CDC data that e-cigarette use "does not discourage and may encourage conventional cigarette use." Abrams argues that such a cross-sectional study cannot support such a bold conclusion.

Amy L. Fairchild, PhD

Amy L. Fairchild, PhD
Professor of Sociomedical Sciences
Mailman School of Public Health
Columbia University, New York City

Ronald Bayer, PhD

Ronald Bayer, PhD
Professor of Sociomedical Sciences
Co-director
Center for the History and Ethics of Public Health
Mailman School of Public Health
Columbia University, New York City

References

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  2. Siegel MB, et al. Electronic cigarettes as a smoking-cessation tool: results from an online survey. American Journal of Preventive Medicine. 2011;40(4):472-75.
  3. Caponnetto P., et al., EffiCiency and safety of an eLectronic cigarette (ECLAT) as tobacco cigarettes substitute: a prospective 12-month randomized control design study. PLOS ONE. 2013 8:9.
  4. Bullen C., et al. Electronic cigarettes for smoking cessation: a randomised controlled trial. Lancet. 2013 382:1629-37.
  5. Lee S, Grana RA, and Glantz SA. Electronic cigarette use among korean adolescents: a cross-sectional study of market penetration, dual use, and relationship to quit attempts and former smoking. Journal of Adolescent Health. 2013:1-7.
  6. Eissenberg T, Electronic nicotine delivery devices: ineffective nicotine delivery and craving suppression after acute administration. Tobacco Control. 2010;19:87-88.
  7. Polosa R, et al. Effectiveness and tolerability of an electronic cigarette in real-life: a 24 month prospective observational study. Intern Emerg Med, 2013, July 20:published online.
  8. Polosa R, et al., Effect of an electronic nicotine delivery device (e-cigarette) on smoking reduction and cessation: a prospective 6-month pilot study. BMC Public Health. 2011 786(11): http://www.biomedcentral.com/1471-2458/11/786.
  9. Adkison SE, et al., Electronic nicotine delivery systems: international tobacco control four-country survey. American Journal of Preventive Medicine. 2013 43(3):207-15.
  10. Goniewicz JL, et al. Levels of selected carcinogens and toxicants in vapour from electronic cigarettes. Tobacco Control 2013 March 6:published online.
  11. Quoted in Hampton T, Experts call for research plus regulation of e-cigarettes. JAMA 2014 Jan 8;311(2):124.
  12. Schripp T, Markewitz D, Uhde E, and Salthammer T. Does e-cigarette Consumption cause passive vaping? Indoor Air. 2013; 23:25-31.
  13. S. Lee, R.A. Grana, and S.A. Glantz, "Electronic Cigarette Use among Korean Adolescents: A Cross-Sectional Study of Market Penetration, Dual Use, and Relationship to Quit Attempts and Former Smoking," Journal of Adolescent Health (2013):1-7.