By K. Michael Cummings, PhD, MPH, and
Graham Warren, MD, PhD
On July 28, 2017, the U.S. Food and Drug Administration (FDA) announced a new emphasis in the federal government’s regulatory framework toward tobacco product regulation. This new emphasis would focus on nicotine and would support innovations to promote tobacco harm reduction based on the continuum of risk for nicotine-containing products.1 The reason for this shift was the recognition that, although people smoke for the nicotine, the toxic smoke in combustible tobacco products is the main culprit in causing tobacco-related diseases and death. Given the FDA’s mandate to protect public health and the recognition that the evolving marketplace of nicotine products now allows smokers to get nicotine from a greater variety of less-dangerous products, the FDA announced a three-pronged regulatory strategy involving:
1. Reducing the nicotine in traditional cigarettes to nonaddictive levels,
2. Increasing the number of approved nicotine replacement therapies available to smokers, and
3. Recognizing the potential of electronic cigarettes (ECs) and other noncombustible nicotine delivery products to help smokers transition away from cigarettes.
Recent Reports: Slightly Different Areas of Emphasis
Two recent comprehensive reviews of the scientific evidence on ECs provide new evidence supporting the FDA’s new regulatory approach. The National Academy of Sciences, Engineering, and Medicine (NASEM) report on the public health consequences of ECs and a new evidence review on ECs and heated tobacco products commissioned by Public Health England (PHE) both come to similar conclusions, although there are differences in what is emphasized in each report.2,3 Both reports acknowledge that using an EC is far less risky than using combustible tobacco cigarettes, that ECs may be helpful to smokers who are trying to stop smoking cigarettes, and that ECs should not be used by nonsmokers, especially youth.1,2 Both reports also acknowledge that ECs contain chemical constituents that are not inert and are likely to have some negative health effects on their own. In other words, ECs are not completely safe to use. Whereas both reports acknowledge that nonsmokers, especially children, should not use ECs, the NASEM report concludes that EC use by youth can lead to increased risk of using cigarettes, whereas the PHE report focuses on population-level effects and found no evidence that the growing popularity of ECs has reversed the declining trend in youth smoking. Both reports recommend that trends in EC use and smoking behaviors by youth should be closely monitored. Additionally, both reports note injuries from exploding EC devices and poisonings from ingestion of e-liquids as concerns that warrant immediate remedial actions by government regulators to improve product safety.
Overall, both reports acknowledge that data evaluating long-term health risks are lacking and that more research is needed to assess health outcomes. The NASEM report is more comprehensive than the PHE report in defining areas where scientific evidence is insufficient to allow reliable conclusions to be made about the risks and benefits of ECs. However, both reports suggest that the risks of cancer, cardiovascular disease, and respiratory diseases due to ECs are expected to be reduced compared with smoking combustible tobacco because toxicants and carcinogens present in cigarette smoke are either absent or are present at much lower concentrations in EC aerosols. Both reports also highlight recent studies showing a marked decline in levels of biomarkers of exposure to toxicants and carcinogens in EC users who do not smoke when compared with smokers, which is strongly suggestive of a health benefit as compared with combustible tobacco. Although the PHE report claims that the overall risk of harm from ECs is estimated at less than 5% compared with smoking tobacco, the NASEM report did not attempt to quantify the relative risks of ECs compared to smoking cigarettes, given the absence of long-term data.
Dr. K. Michael Cummings
Dr. Graham Warren
Although the conclusions from these reports are useful to provide general consensus on the potential health effects of ECs, there remain many unanswered questions for real-world applications. For example, dual use of cigarettes and ECs is a controversial real-world pattern of use that remains a public health concern for two primary reasons: dual use is a prevalent but understudied phenomenon observed in the general population, and potential health benefits gained from using ECs may be reduced or negated by continued smoking. Research is needed to better understand and define dual use of ECs and smoking as different patterns of use that are likely to affect estimates of the risks and benefits of ECs on population health.
Both reports suggest that ECs may help smokers transition away from cigarette use, but conclusive evidence of a benefit for smoking cessation remains unclear, particularly as it relates to sustained long-term abstinence from smoking. Much of the difficulty in establishing a benefit for ECs has do with the scarcity of randomized controlled trials demonstrating a benefit for ECs as a cessation aid. Data from observational studies appear to be increasingly supportive of a benefit of ECs for smoking cessation but are also much harder to interpret due to selection biases, variations in the types of ECs used by smokers, and variability in the patterns of use of ECs. Converging evidence suggests that cigarette smokers who switch completely to ECs and use them on a regular, daily basis are more likely to remain off cigarettes compared to those who quit unassisted or use cigarettes and ECs simultaneously (i.e., dual use). Carefully designed studies are needed to conclusively support the efficacy of ECs for long-term smoking cessation and to identify individuals who will benefit most from ECs as a cessation aid.
The Bottom Line
Although the evidence of ECs’ risks and benefits remains incomplete, the overarching message from both of these evidence reviews is that across a range of studies and outcomes, ECs pose less risk to an individual than combustible tobacco cigarettes.2-4 For clinicians who are confronted with the task of advising their patients about the risks and benefits of ECs, they can now tell smokers that that although many of the effects of ECs are still unknown, data increasingly suggest that ECs pose a fraction of the risk of smoking cigarettes.5 In contrast to the evolving potential risks associated with ECs, there is unequivocal evidence of the adverse effects of smoking across a broad spectrum of health conditions.1-3 Despite this evidence, many smokers falsely believe that vaping is as harmful as smoking, but data simply do not support these beliefs.3 Smokers should be clearly counseled that smoking is a proven risk factor for poor health and should be encouraged to abandon their cigarettes either with FDA-approved smoking-cessation medications or by switching to ECs, if used to keep them from smoking.5,6 ✦
About the Authors: Dr. Cummings is a Professor and Co-leader of the Tobacco Research Program in the Department of Psychiatry and Behavioral Sciences and Member of the Cancer Prevention and Control Program, Hollings Cancer Center, Medical University of South Carolina. Dr. Warren is a Professor Joint Appointment (Primary Appointment in Radiation Oncology), Vice Chairman for Research in Radiation Oncology, and Member of the Cancer Prevention and Control Program, Hollings Cancer Center, Medical University of South Carolina.
1. Gottlieb S, Zeller M. A Nicotine-Focused Framework for Public Health. N Engl J Med. 2017;377(12):1111-1114.
2. National Academies of Sciences, Engineering, and Medicine. Public Health Consequences of E-Cigarettes. Washington, DC: The National Academies Press; 2018.
3. McNeill A, Brose LS, Calder R, et al. Evidence Review of E-Cigarettes and Heated Tobacco Products: A Report Commissioned by Public Health England. London: Stationery Office; 2018. https://www.gov.uk/government/publications/e-cigarettes-and-heated-tobacco-products-evidence-review Accessed February 7, 2018.
4. Newton JN, Dockrell M, Marczylo T. Making sense of the latest evidence on electronic cigarettes. Lancet. 2018 Feb 5. [Epub ahead of print].
5. Wise JW. Doctors should state clearly that vaping is much lower risk than smoking, says report. BMJ. 2018;360:k575.
6. American Cancer Society. ACS Position Statement on Electronic Cigarettes. https:// www.cancer.org/ecigaretteposition