The advent of electronic cigarettes (e-cigarettes), devices that deliver a nicotine aerosol to the lungs by heating a nicotine-containing liquid rather than burning tobacco, has triggered an intense debate over their value for reducing the harm tobacco products cause. The optimists see e-cigarettes delivering nicotine without all the combustion byproducts of conventional cigarettes,1 whereas others point out that e-cigarettes still deliver an aerosol of ultrafine particles and other toxicants that carry substantial health risks.2
A key to realizing the optimists’ vision for e-cigarettes is smokers switching completely from cigarettes to e-cigarettes. Because perceived risks play an important role in selecting tobacco products, Huang and colleagues3 examined how perceptions of the risk of e-cigarettes compared with cigarettes have changed from 2012 to 2017 using 2 national surveys, the Tobacco Products and Risk Perceptions Surveys they conducted and the Health Information National Trends Surveys (HINTS). They found that the fraction of respondents who believed that e-cigarettes were less harmful than cigarettes decreased from approximately 45% in 2012 to approximately 35% in 2017, whereas the fraction who thought they were about the same increased to approximately 45%. (These estimates combine the 2 surveys. The estimates of “about the same” in 2012 were very different in the 2 surveys, so are not listed here; the other results were more similar.) The fractions who thought e-cigarettes were more dangerous than cigarettes increased but remained low, at less than 10%.
Huang and colleagues3 express concern that as fewer people view e-cigarettes as less harmful than cigarettes, fewer will be interested in switching from combustible cigarettes to e-cigarettes. Based on the evidence available in 2017, the National Academies of Science, Engineering, and Medicine concluded that “e-cigarettes pose less risk to an individual than combustible tobacco cigarettes.”4(p11) The report emphasized that at the time, no studies on the long-term health effects of e-cigarettes had been performed, which they recognized as a limitation. However, the data are catching up with public perception.
Since the report was completed, evidence has started to emerge that e-cigarette users are at increased risk of myocardial infarction,5-7 stroke,6 and chronic obstructive pulmonary disease and other respiratory diseases,8-10 controlling for smoking and other demographic and risk factors. Some of these risks approach those of smoking cigarettes. There is also emerging evidence that e-cigarettes deregulate biologically significant genes associated with cancer.11 Equally important, the risks of e-cigarette use are in addition to any risks of cigarette smoking, which means that dual users (people who continue to smoke cigarettes while using e-cigarettes) have higher risks of heart and lung disease than people who just smoke. This finding is particularly important because, contrary to the hopes of the e-cigarette optimists, about two-thirds of adult e-cigarette users are dual users (ie, continue to smoke).
In addition, although 1 randomized clinical trial12 has shown that e-cigarettes improve cessation when used as part of a clinically supervised smoking cessation program that includes intensive counseling, as used in the population as a whole as a mass-marketed consumer product, e-cigarettes are associated with reduced odds of cessation.13 In addition, 80% of former cigarette smokers were continuing to use e-cigarettes 6 month later. Although not a direct health effect (in the same way that exposure to e-cigarette aerosol triggers pathophysiological processes that increase the risk of heart and lung disease), this effect of depressing smoking cessation in the population as a whole is another risk of using e-cigarettes.
Increased perceived risks of e-cigarettes is also an important element for curbing their use by youth. Youth who believe that e-cigarettes are not harmful or are less harmful than cigarettes are more likely to use e-cigarettes than youth with more negative views of e-cigarettes.14 In terms of overall public health effects, this explosion of youth use swamps any potential harm reduction that may accompany adults switching from cigarettes to e-cigarettes.15 From this perspective, the declining public perception that e-cigarettes are less harmful than cigarettes is a good thing that may turn out to be where the scientific consensus lands as the new evidence on the harms of e-cigarettes continues to accumulate.
Published: March 29, 2019. doi:10.1001/jamanetworkopen.2019.1032
Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2019 Glantz SA. JAMA Network Open.
Corresponding Author: Stanton A. Glantz, PhD, Center for Tobacco Control Research and Education, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143 (firstname.lastname@example.org).
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by grants R01DA043950 from the National Institute of Drug Abuse, P50CA180890 from the National Cancer Institute and the US Food and Drug Administration (FDA) Center for Tobacco Products, U54HL147127 from the National Heart, Lung and Blood Institute and the FDA Center for Tobacco Products, and the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center Global Cancer Program.
Role of the Funder/Sponsor: The funding sources had no role in the preparation, review, or approval of the manuscript and decision to submit the manuscript for publication.
Disclaimer: The content is solely the responsibility of the author and does not necessarily represent the official views of NIH or the FDA.
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Glantz SA. The Evidence of Electronic Cigarette Risks Is Catching Up With Public Perception. JAMA Netw Open. 2019;2(3):e191032. doi:10.1001/jamanetworkopen.2019.1032
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