Myth: Alternative nicotine products are a gateway to smoking

Is the use of reduced-risk nicotine products like vapes, snus, nicotine pouches, etc., a gateway to smoking combustible tobacco? Can the use of these products be a gateway to an addiction to illicit substances and criminal activity to support that addiction?

Is it possible for reduced-risk products to be a gateway away from smoking? (A less harmful substitute.)

Your Safer Nicotine Wiki (SNW) team explores the answers to those questions below.

The Gateway Hypothesis

Science Hygiene

Nicotine - Retracted Studies, Papers, and Articles

• For commentaries on papers indicating the possibility of a gateway effect, please see the "Gateway" section of the Retractions SNW page.

Papers

2024: The “Gateway” hypothesis: evaluation of evidence and alternative explanations

• Conclusion: "Evidence offered in support of the gateway hypothesis does not establish that ENDS use causes youth to also smoke cigarettes. Instead, this evidence is better interpreted as resulting from a common liability to use both ENDS and cigarettes. Population-level trends are inconsistent with the gateway hypothesis, and instead are consistent with (but do not prove) ENDS displacing cigarettes. Policies based on misinterpreting a causal gateway effect may be ineffective at best, and risk the negative unintended consequence of increased cigarette smoking."
  • Citation: Selya, A. The “Gateway” hypothesis: evaluation of evidence and alternative explanations. Harm Reduct J 21, 113 (2024). https://doi.org/10.1186/s12954-024-01034-6
    • Acknowledgment: The author thanks Joe Gitchell, Sooyong Kim, and Saul Shiffman, all of Pinney Associates, Inc. for their feedback on an early draft of this manuscript, and Floe Foxon and Sooyong Kim for assistance with manuscript formatting. Through Pinney Associates, Inc., AS provides consulting services on tobacco harm reduction to Juul Labs, Inc. (JLI). JLI partially supported the preparation of this manuscript, and reviewed and commented on a near-final version. After the initial submission of this manuscript, AS also began individually providing consulting services on behavioral science to the Center of Excellence for the Acceleration of Harm Reduction (CoEHAR) through ECLAT Srl, which received funding from the Foundation for a Smoke-Free World (FSFW). Neither CoEHAR nor FSFW had any role in, or oversight of, this commentary.

2015: Gateway Effects: Why the Cited Evidence Does Not Support Their Existence for Low-Risk Tobacco Products (and What Evidence Would)

• "Searching for some signal of a gateway effect amidst overwhelming confounding and reverse causation requires more rigorous methods than are typical in public health epidemiology. This generalizes to any attempt to use cross-sectional data to sort out causation in a particular direction from confounding or reverse causation. When seeking epidemiologic associations where confounding is minimal or relatively simple in its causes, the typical methods used in the field are still far from optimal, but the empirical results might still be basically useful. That is not the case in this context. While it might never be possible to convincingly demonstrate a gateway effect given the challenges, and statistical analyses have no hope of detecting a tiny effect, there are clearly better and worse ways to pursue the question."
  • Citation: Phillips CV. Gateway Effects: Why the Cited Evidence Does Not Support Their Existence for Low-Risk Tobacco Products (and What Evidence Would). International Journal of Environmental Research and Public Health. 2015; 12(5):5439-5464. https://doi.org/10.3390/ijerph120505439
    • Acknowledgment: The author’s work on this paper was supported by CASAA. CASAA is a public health NGO that represents the interests of consumers; it is dedicated to protecting consumers’ access to THR products and to promoting THR. Some of the research incorporated here, though not the creation of this paper itself, took place in 2014 when the author was the recipient of an unrestricted grant from British American Tobacco for support of his research. The author is the recipient of grant (unrestricted except for the general subject matter) from Imperial Tobacco Group for research on peer review in the health sciences; that topic is tangential to the main analysis, but some observations address it.

Resources

2023: Summary of Gateway Studies - Mendelsohn

• "There is a longitudinal association between adolescent vaping and smoking initiation. However after adjusting for covariates (common risk factors eg demographic characteristics, use of other psychoactive substances, perceived peer cigarette use, risk-taking, socially maladaptive behaviors, attitude toward smoking, and parental education using propensity scoring), the association reduces substantially or disappears completely."

2023: VAPING AND THE GATEWAY MYTH

• "Vaping has been extensively accused of being a gateway to smoking for adults and adolescents. Multiple studies have aimed to undermine the credibility of e-cigarettes as a cessation tool, and there is an urgent need to shift the Overton window of the debate and outline a science-based perspective that policymakers can use to enhance the wellbeing of consumers..."

2016: How not to be duped by gateway effect claims

• "Sometimes studies appear that can create the appearance of the discovery of a ‘gateway effect’ – the idea that vaping causes young people to progress to smoking...Here is an eight-point guide to evaluating such studies and the politically motivated claims that often go with them."

Product Substitution - Does it help explain the impression of a gateway?

See these SNW pages for examples of product substitution:

• ENDS Taxes
• Age Restrictions
• Flavor Bans
• A cautionary note: misperceptions about less harmful alternatives to smoking combustible tobacco can keep some people smoking. There is also the risk of young people who want to experiment using nicotine choosing to smoke because they've been led to believe that vaping is more harmful than smoking and will give them illnesses such as popcorn lung. There have been instances of people taking up smoking as a means to stop vaping. (It is never safer to smoke tobacco cigarettes than it is to vape nicotine!)

Smokeless Products (Excludes Vaping)

2019: Snus: a compelling harm reduction alternative to cigarettes

• "A review of the evidence [106] which examined gateway effects in Sweden suggested that snus appeared to lead users away from smoking rather than towards it and is an important reason why Sweden has the lowest rates of tobacco-related disease in Europe."
  • Citation: Clarke, E., Thompson, K., Weaver, S. et al. Snus: a compelling harm reduction alternative to cigarettes. Harm Reduct J 16, 62 (2019). https://doi.org/10.1186/s12954-019-0335-1
    • Acknowledgement: The review was funded by Imperial Brands Plc. EC, SW, JT and GOC are employees of Imperial Brands Plc. KT is an employee of Elucid8 Holdings Ltd and is acting as an independent scientific consultant to Imperial Brands Plc. KT is a former employee of Gallaher Ltd and Japan Tobacco International UK Ltd.

Evaluates Two or More Reduced-Risk Products

2015: Which Nicotine Products Are Gateways to Regular Use?

• "Though this finding should be interpreted with caution, it potentially indicates that current ETPs are not necessarily strong gateways to regular tobacco use." (Note: ETP=Emergining Tobacco Products such as dissolvables, snus, and electronic cigarettes).
  • Citation: Meier EM, Tackett AP, Miller MB, Grant DM, Wagener TL. Which nicotine products are gateways to regular use? First-tried tobacco and current use in college students. Am J Prev Med. 2015 Jan;48(1 Suppl 1):S86-93. doi: 10.1016/j.amepre.2014.09.018. PMID: 25528714.
    • Acknowledgement: Publication of this article was supported by the Oklahoma Tobacco Research Center (OTRC), with funding from the Oklahoma Tobacco Settlement Endowment Trust (TSET).

Vaping Nicotine

2024: Increased e-cigarette use prevalence is associated with decreased smoking prevalence among US adults

• Nationally representative population-level data on tobacco product use by US adults continue to support the existence of an association between increasing prevalence of e-cigarette use and decreasing prevalence of cigarette smoking, i.e., possible substitution between cigarettes and e-cigarettes.
  • Citation: Foxon F, Selya A, Gitchell J, Shiffman S. Increased e-cigarette use prevalence is associated with decreased smoking prevalence among US adults. Harm Reduct J. 2024 Jul 18;21(1):136. doi: 10.1186/s12954-024-01056-0. PMID: 39026245; PMCID: PMC11256395.
    • Acknowledgment: Through PinneyAssociates, FF, AS, JG, and SS provide consulting services on tobacco harm reduction on an exclusive basis to Juul Labs Inc. The preparation of the previously-published version of this manuscript was funded by JLI, who reviewed and provided comments on a draft manuscript of the previously-published version. The present, updated version did not receive any funding or review from JLI, and was self-funded by PinneyAssociates. The content and the decision to publish are the responsibility of the authors. JG and SS also own interest in a novel nicotine gum that has neither been developed nor commercialized.

2024: Electronic cigarettes and subsequent use of cigarettes in young people: An evidence and gap map

• "This evidence and gap map (EGM) offers a tool to explore the available evidence regarding the e-cigarette use/availability and later cigarette smoking in people under the age of 30 years at the time of the search."
  • Citation: Conde M, Tudor K, Begh R, Nolan R, Zhu S, Kale D, Jackson S, Livingstone-Banks J, Lindson N, Notley C, Hastings J, Cox S, Pesko MF, Thomas J, Hartmann-Boyce J. Electronic cigarettes and subsequent use of cigarettes in young people: An evidence and gap map. Addiction. 2024 Jun 27. doi: 10.1111/add.16583. Epub ahead of print. PMID: 38937796.
    • Acknowledgment: This research work was funded by Cancer Research UK under Grant Number PPRCTAGPJT\100002. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funder. M.C., J.H., S.Z., R.N., J.L.B., K.T., R.B. and J.T. declare no competing interests. J.H.B. declares current funding from the Food and Drug Administration; no other competing interests. C.N. is an associate editor at Addiction and the first author of an included study. C.N. was not involved in the screening, coding or quality appraisal of this study; no other competing interests. S.C. is a senior editor at Addiction and the co-author of an included study. S.C. was not involved in the screening, coding or quality appraisal of this study; no other competing interests. S.J. is a senior editor at Addiction; no other competing interests. D.K. is an associate editor at Addiction, no other competing interests. N.L. is an associate editor at Addiction; no other competing interests. M.P.'s research is supported by the National Institute on Drug Abuse of the National Institutes of Health under Award Number R01DA045016. M.P. declares current funding from the Food and Drug Administration, the American Cancer Society, University of Kentucky Institute for the Study of Free Enterprise and Health Canada. M.P. is the first author and co-author of included studies and was not involved in the screening or coding of these studies; no other competing interests.

2024: Commentary on Conde et al.: Evidence and gap map offer an important opportunity for dialogue and refinement of the gateway hypothesis controversy

• "The recent Cochrane-affiliated evidence and gap map on the e-cigarette gateway hypothesis creates a valuable opportunity for these well-respected and impartial authors to bridge the divide in opinion by working with all sides to refine definitions of a ‘gateway’ and types of evidence in subsequent research."
  • Citation: Selya A, Gitchell JG. Commentary on Conde et al.: Evidence and gap map offer an important opportunity for dialogue and refinement of the gateway hypothesis controversy. Addiction. 2024 Aug 12. doi: 10.1111/add.16645. Epub ahead of print. PMID: 39129582.
    • Acknowledgment: Funding information - There are no funders to report. Through Pinney Associates, A.S. and J.G.G. provide consulting services on tobacco harm reduction to Juul Labs (JLI). A.S. also individually provides consulting services on behavioural science to the Center of Excellence for the Acceleration of Harm Reduction (CoEHAR) through ECLAT Srl, which received funding from the Foundation for a Smoke-Free World (FSFW; now the Global Action to End Smoking [GA]). Neither JLI, CoEHAR, nor FSFW/GA had any role in, or oversight of, this commentary.

2024: A systematic review and meta-analysis of the association between e-cigarette use among non-tobacco users and initiating smoking of combustible cigarettes

• "Based on findings from this review, the available studies neither sufficiently measure e-cigarette use—or cigarette smoking—in a manner consistent with examining causality, nor sufficiently account for known or suspected confounding variables to support robust determinations regarding e-cigarette use and cigarette smoking behaviors. Thus, the utility of the evidence base for policymakers, healthcare providers, and researchers is limited."
  • Citation: Kim MM, Steffensen I, Miguel RTD, Babic T, Carlone J. A systematic review and meta-analysis of the association between e-cigarette use among non-tobacco users and initiating smoking of combustible cigarettes. Harm Reduct J. 2024 May 22;21(1):99. doi: 10.1186/s12954-024-01013-x. PMID: 38773514; PMCID: PMC11110305.
    • Acknowledgment: All study activities were executed by providers external to RAI Services Company (Thera-Business), who were financially compensated for services according to contractual terms with RAI Services Company. RAI Services Company is a wholly owned subsidiary of Reynolds American Inc., whose operating companies manufacture and market tobacco products. The conception, analysis, and writing for this manuscript was a collaboration between Thera-Business and RAI Services Company. Dr. Kim is a former full-time employee of RAI Services Company, a wholly owned subsidiary of Reynolds American Inc.

2024: Trends in vaping and smoking following the rise of disposable e-cigarettes: a repeat cross-sectional study in England between 2016 and 2023

• "... At the same time, smoking declines appeared to be most pronounced in age groups with the largest increases in vaping, which suggests the potential for policy trade-offs. Policies should be proportionate and try to balance the risk that excessive restrictions on vaping products may be associated with increases in cigarette smoking (as occurred in US states following vape flavour bans and taxation)."
  • Citation: Trends in vaping and smoking following the rise of disposable e-cigarettes: a repeat cross-sectional study in England between 2016 and 2023, Tattan-Birch H., Brown J., Shahab L., Beard E., Jackson S.E. (2024) The Lancet Regional Health - Europe, 42 , art. no. 100924
    • Acknowledgment: Funding: Cancer Research UK funds the Smoking Toolkit Study in England and provides salary support for HTB and SJ (PRCRPG-Nov21/100002). The Smoking Toolkit Study in Scotland and Wales is funded by the UK Prevention Research Partnership (MR/S037519/1). The UK Prevention Research Partnership is funded by the British Heart Foundation, Cancer Research UK, Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Health and Social Care Research and Development Division (Welsh Government), Medical Research Council, National Institute for Health Research, Natural Environment Research Council, Public Health Agency (Northern Ireland), The Health Foundation and Wellcome. For the purpose of Open Access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. HTB and SJ declare no conflicts of interest. JB has received unrestricted research funding to study smoking cessation from manufacturers of smoking cessation medications (Pfizer; Johnson & Johnson). LS has received honoraria for talks, unrestricted research grants and travel expenses to attend meetings and workshops from manufactures of smoking cessation medications (Pfizer; Johnson & Johnson), and has acted as paid reviewer for grant awarding bodies and as a paid consultant for health care companies.

2023: Dramatic Reductions in Cigarette Smoking Prevalence among High School Youth from 1991 to 2022 Unlikely to Have Been Undermined by E-Cigarettes

• Conclusion: Healthy People’s 2030 goal for youth cigarette smoking, which uses the NYTS as its benchmark, has already been achieved and exceeded, years ahead of schedule. Concerns about a potential rise in adolescent cigarette use following the introduction of e-cigarettes to the U.S. market in the early 2010s are not supported by the data. In fact, the emergence of e-cigarettes has coincided with the most rapid declines in cigarette use over the past thirty years. It is important to recognize the possibility that had e-cigarettes not been available, changes in cigarette smoking prevalence among youth may have been different; this includes slower or faster declines. However, given the lack of a counterfactual, it is not possible to empirically evaluate this.
  • Citation: Delnevo CD, Villanti AC. Dramatic Reductions in Cigarette Smoking Prevalence among High School Youth from 1991 to 2022 Unlikely to Have Been Undermined by E-Cigarettes. International Journal of Environmental Research and Public Health. 2023; 20(19):6866. doi.org/10.3390/ijerph20196866
    • Acknowledgment: C.D.D. and A.C.V. were supported in part by a grant from the National Cancer Institute of the National Institutes of Health and the FDA Center for Tobacco Products (U54CA229973 and U01CA278695. The content is solely the responsibility of the authors and does not necessarily represent the official views of NIH, NCI or FDA.

2023: Effects of reduced-risk nicotine-delivery products on smoking prevalence and cigarette sales: an observational study

• "We detected some indications that alternative nicotine products are competing with cigarettes rather than promoting smoking and that regulations that allow their sales are associated with a reduction rather than an increase of smoking, but the findings are inconclusive because of insufficient data points and issues with the assumptions of the pre-specified statistical analyses."
  • Citation: Pesola F, Phillips-Waller A, Beard E, Shahab L, Sweanor D, Jarvis M & Hajek P. Effects of reduced-risk nicotine-delivery products on smoking prevalence and cigarette sales: an observational study. Public Health Res 2023;11(7)
    • Acknowledgment: This project was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR129968) and will be published in full in Public Health Research; Vol. 11, No. 7. See the NIHR Journals Library website for further project information.

2023: e-Cigarette and Cigarette Use Among Youth: Gateway or Common Liability?

• "Collectively, concerns about a gateway effect and a potential increase in youth cigarette use following the introduction of e-cigarettes to the US market are not supported by the data. Moreover, future research and policy efforts should give more attention to the common liability theory and consider that in the context of a complex tobacco marketplace, increased diversity in the types of products, brands, and flavors fundamentally provides more opportunities for youths to experiment with tobacco and nicotine products."
  • Citation: Delnevo CD. e-Cigarette and Cigarette Use Among Youth: Gateway or Common Liability? JAMA Netw Open. 2023;6(3):e234890. doi:10.1001/jamanetworkopen.2023.4890
    • Acknowledgment: Dr Delnevo reported receiving grants from the National Cancer Institute and serving as the chair of the US Food and Drug Administration’s Tobacco Product Scientific Advisory Board outside the submitted work.

2023: Predictors of E-cigarette and Cigarette Use Trajectory Classes from Early Adolescence to Emerging Adulthood Across Four Years (2013–2017) of the PATH Study

• Conclusion: "There was no evidence that initiation with e-cigarettes as the first product tried was associated with cigarette progression (nor cigarettes as first product and e-cigarette progression). Interventions should focus on well-established risk factors such as mental health and other substance use to prevent progression of use for both tobacco products."
  • Citation: Stanton CA, Tang Z, Sharma E, Seaman E, Gardner LD, Silveira ML, Hatsukami D, Day HR, Cummings KM, Goniewicz ML, Limpert J, Everard C, Bansal-Travers M, Ambrose B, Kimmel HL, Borek N, Compton WM, Hyland AJ, Pearson JL. Predictors of E-cigarette and Cigarette Use Trajectory Classes from Early Adolescence to Emerging Adulthood Across Four Years (2013-2017) of the PATH Study. Nicotine Tob Res. 2023 Feb 9;25(3):421-429. doi: 10.1093/ntr/ntac119. PMID: 35554569; PMCID: PMC9910140.
    • Acknowledgment: This work was supported by Federal funds from the National Institute on Drug Abuse, National Institutes of Health; and the Center for Tobacco Products, Food and Drug Administration, Department of Health and Human Services, under a contract to Westat (Contract No. HHSN271201100027C). The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the U.S. Department of Health and Human Services or any of its affiliated institutions or agencies. K. Michael Cummings has received grant funding from the Pfizer, Inc., to study the impact of a hospital-based tobacco cessation intervention. Dr. Cummings also receives funding as an expert witness in litigation filed against the tobacco industry. Maciej Goniewicz has received a research grant from Pfizer and served as a member of a scientific advisory board to Johnson & Johnson, a pharmaceutical company that manufactures smoking cessation medications. Wilson Compton reports holding stock in General Electric, 3M Companies and Pfizer. Jennifer Pearson is an expert witness for the Plaintiffs in a multi-district litigation invoking American Spirit Cigarettes.

2023: Impact of e-cigarette experimentation and use on smoking behavior among adolescents aged 15–16 years in the Loire department, France

• "In our study, the low percentage of adolescents who reported using e-cigarettes before initiating smoking and the significant percentage of non-smokers who used nicotine-free e-cigarettes do not support the existence of a gateway effect. This is in line with many studies conducted in the school setting in which vaping was not a gateway to smoking."
  • Citation: Wamba A, Pourchez J, Masson J, Denis-Vatant C, Leclerc L, Nekaa M. Impact of e-cigarette experimentation and use on smoking behavior among adolescents aged 15-16 years in the Loire department, France. Tob Prev Cessat. 2023 Jun 22;9:21. doi: 10.18332/tpc/163416. PMID: 37363269; PMCID: PMC10286514.
    • Acknowledgment: This work was supported by a grant (AAP TABAC 2019) from the French National Cancer Institute (INCa) and French Public Health Research Institute (IReSP). Both funding agencies have no role in the study design, collection, analysis, or interpreting of the data, writing the manuscript, or the decision to submit the article for publication.

2023: Regional French evolution of tobacco and e-cigarette experimentation and use among adolescents aged 15–16 years: A cross-sectional observational study conducted in the Loire department from 2018 to 2020

• Conclusion: "Adolescents used e-cigarettes mainly for experimental and/or recreational purposes, with no intention of progression to daily smoking. Although the design of this study is not longitudinal and caution must be exercised, from our cross-sectional observational study data, it appears that the proportion of “non-vapers and non-smokers” tended to increase. “Smokers” tended to progress to the dual use of vaping and smoked tobacco, with the likely intention to reduce or quit smoking."
  • Citation: Wamba A, Nekaa M, Leclerc L, Denis-Vatant C, Masson J, Pourchez J. Regional French evolution of tobacco and e-cigarette experimentation and use among adolescents aged 15-16 years: A cross-sectional observational study conducted in the Loire department from 2018 to 2020. Prev Med Rep. 2023 Jun 9;35:102278. doi: 10.1016/j.pmedr.2023.102278. PMID: 37389205; PMCID: PMC10300395.
    • Acknowledgment: This work was supported by a grant from the French National Cancer Institute (INCa) and French Public Health Research Institute. Both funding agencies have no role in the study design, collection, analysis, or interpreting of the data, writing the manuscript, or the decision to submit the paper for publication. Authors declared no funding and connection to tobacco/vaping industry.

2023: The relationship between first tobacco product tried and current use of cigarettes and electronic cigarettes among adolescents from private schools in Guatemala City Tobacco trial and current use

• "Compared to those who first tried cigarettes, students who first tried e-cigarettes were less likely to be current smokers (RR=0.19 [CI: 0.11 – 0.31]) or dual users..."
  • Citation: Mus S, Monzon J, Islam F, Thrasher JF, Barnoya J. First tobacco product tried and current use of cigarettes and electronic cigarettes among adolescents from Guatemala City. Salud Publica Mex. 2023 Jan 2;65(1, ene-feb):46-53. doi: 10.21149/13972. PMID: 36750072; PMCID: PMC11091932.
    • Acknowledgment: This study was supported by a grant from the Fogarty International Center and National Cancer Institute of the National Institutes of Health (R01 TW010652). The funding agency played no role in study design, in the collection, analysis and interpretation of data, in the writing of the report and in the decision to submit the article for publication. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

2023: Association of Electronic Cigarette Use by US Adolescents With Subsequent Persistent Cigarette Smoking

• Conclusion: "In this cohort study of cigarette-naive respondents, we examined the association of adolescent e-cigarette use at baseline with continued cigarette smoking 3 years later, following smoking initiation a year after baseline. Our findings suggest very different interpretations of the association as measured by absolute and relative risk. The minor risk differences in continued smoking among baseline e-cigarette users and nonusers, together with the small magnitude of absolute risks for both groups, suggest that regardless of baseline e-cigarette use, few adolescents were likely to report continued smoking after initiation."
  • Citation: Sun R, Méndez D, Warner KE. Association of Electronic Cigarette Use by US Adolescents With Subsequent Persistent Cigarette Smoking. JAMA Netw Open. 2023;6(3):e234885. doi:10.1001/jamanetworkopen.2023.4885
    • Acknowledgment: Drs Méndez and Warner received support from the National Cancer Institute of the National Institutes of Health (NIH) and the Food and Drug Administration’s (FDA) Center for Tobacco Products (award number U54CA229974). The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

2023: Systematic Review and Critical Analysis of Longitudinal Studies Assessing Effect of E-Cigarettes on Cigarette Initiation among Adolescent Never-Smokers

• "The interactions between e-cigarettes and cigarettes in adolescents are not only one-way. Cross-sectional studies show a decline in tobacco use as well as an increase in e-cigarette use among adolescents, suggesting that e-cigarettes generally turn potential smokers away from tobacco since they first appeared on the market (Diversion effect). However, most longitudinal studies conclude the existence of a general Gateway effect of e-cigarettes toward cigarette initiation. The discrepancy between the two sources comes mainly from the fact that the longitudinal studies rely on small sub-cohorts of individuals who do not smoke tobacco and may switch from e-cigarettes to cigarettes."
• "While nicotine abstinence remains the best medical option, over-regulation of e-cigarettes among youth because of misinterpretation of results of longitudinal studies may be detrimental to public health and tobacco control."
  • Citation: Dautzenberg B, Legleye S, Underner M, Arvers P, Pothegadoo B, Bensaidi A. Systematic Review and Critical Analysis of Longitudinal Studies Assessing Effect of E-Cigarettes on Cigarette Initiation among Adolescent Never-Smokers. Int J Environ Res Public Health. 2023 Oct 18;20(20):6936. doi: 10.3390/ijerph20206936. PMID: 37887674; PMCID: PMC10606427.
    • Acknowledgment: This research received no external funding.

2022: Analysis of common methodological flaws in the highest cited e-cigarette epidemiology research

• "The body of literature on “gateway” theory for the initiation of smoking was particularly unreliable. Overall, the results and discussion contained numerous unreliable assertions due to poor methods, including data collection that lacked relevance, and assertions that were unfounded. Many researchers claimed to find a causal association while not supporting such findings with meaningful data: the discussions and conclusions of such studies were, therefore, misleading."
  • Citation: Hajat, C., Stein, E., Selya, A. et al. Analysis of common methodological flaws in the highest cited e-cigarette epidemiology research. Intern Emerg Med 17, 887–909 (2022). https://doi.org/10.1007/s11739-022-02967-1
    • Acknowledgment: This investigator-initiated study was sponsored by ECLAT srl, a spin-off of the University of Catania, with the help of a grant from the Foundation for a Smoke-Free World Inc., a US nonprofit 501(c)(3) private foundation with a mission to end smoking in this generation. The contents, selection, and presentation of facts, as well as any opinions expressed herein are the sole responsibility of the authors and under no circumstances shall be regarded as reflecting the positions of the Foundation for a Smoke-Free World, Inc. ECLAT srl. is a research based company from the University of Catania that delivers solutions to global health problems with special emphasis on harm minimization and technological innovation. (See study for information on the authors)

2022: United States public health officials need to correct e-cigarette health misinformation

• RE Gateway: "However, significant evidence now exists that this association between vaping and smoking is not causal, which is a source of confusion for the lay public and health-care professionals."
  • Citation: Pesko MF, Cummings KM, Douglas CE, Foulds J, Miller T, Rigotti NA, Warner KE. United States public health officials need to correct e-cigarette health misinformation. Addiction. 2023 May;118(5):785-788. doi: 10.1111/add.16097. Epub 2022 Dec 12. PMID: 36507802.
    • Acknowledgment: M.F.P. reports recent funding from the National Institutes of Health, Food and Drug Administration Center for Tobacco Products; American Cancer Society; Virginia Foundation for Healthy Youth; the University of Kentucky’s Institute for the Study of Free Enterprise; and Health Canada. N.A.R.'s research is primarily funded by the National Institutes of Health. She has also received research funding from and consulted with Achieve Life Sciences to evaluate an investigational smoking cessation medication. K.M.C. has served as a paid expert witness in litigation filed against cigarette manufacturers. J.F. has recently performed paid consulting for Johnson & Johnson pharmaceutical company on smoking cessation medicines and has received a research grant from the National Jewish Health (healthcare organization) on telephone smoking cessation counseling. His research on e-cigarettes is funded by the National Institutes of Health (NIDA). C.D. is a co-principal investigator for research conducted through the Center for the Assessment of Tobacco Regulations, which is funded by NIH/FDA. He is also an advisor to the Smoking Cessation Leadership Center at the University of California San Francisco relating to behavioral health and tobacco use. K.E.W.’s research is supported in part by a Tobacco Center of Regulatory Science grant to the University of Michigan and Georgetown University from the Food and Drug Administration and National Cancer Institute (award no. U54CA229974). T.M. is the acting Attorney General for the State of Iowa and is responsible for representing the state in any legal matters. The opinions expressed in this article are the authors’ own and do not necessarily reflect the views of any of the organizations and government agencies that have provided support to the authors.

2022: ASH brief for local authorities on youth vaping

• "There is NOT strong evidence that vaping is a gateway into smoking. Some who try vaping first may go on to smoke cigarettes, but this association works both ways and there are common risk factors for both behaviours; this does not prove that vaping caused subsequent smoking."

2022: Unpacking the Gateway Hypothesis of E-Cigarette Use: The Need for Triangulation of Individual- and Population-Level Data

• "Based on the current balance of evidence, using triangulated data from recent population-level cross-contextual comparisons, individual-level genetic analyses and modeling, we do believe, however, that causal claims about a strong gateway effect from e-cigarettes to smoking are unlikely to hold, while it remains too early to preclude other smaller or opposing effects."
  • Citation: Shahab L, Brown J, Boelen L, Beard E, West R, Munafò MR. Unpacking the Gateway Hypothesis of E-Cigarette Use: The Need for Triangulation of Individual- and Population-Level Data. Nicotine Tob Res. 2022 Jul 13;24(8):1315-1318. doi: 10.1093/ntr/ntac035. PMID: 35137222; PMCID: PMC9278819.
    • Acknowledgment: The salary of LS is Higher Education Funding Council for England (HEFCE) funded. JB’s and EB’s salaries are funded by Cancer Research UK (C1417/A22962). LB is an employee of Sandtable, Ltd. LS, EB, and JB are members of the SPECTRUM, a UK Prevention Research Partnership Consortium (MR/S037519/1). UKPRP is an initiative funded by the UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK devolved administrations, and leading health research charities. LS has received a research grant and honoraria for a talk and travel expenses from manufacturers of smoking cessation medications (Pfizer and Johnson & Johnson). JB and EB have received unrestricted research funding from Pfizer to study smoking cessation. RW reports grants and personal fees from companies that develop and manufacture smoking cessation medications, outside the submitted work. MRM has received unrestricted research funding fromPfizerandRusanto study smoking cessation.

2022: Association of quarterly prevalence of e-cigarette use with ever regular smoking among young adults in England: a time–series analysis between 2007 and 2018

• Conclusion: The increase in prevalence of e-cigarette use in England among the entire sample does not appear to have been associated with an increase in the uptake of smoking among young adults aged 16–24.
  • Citation: Beard E, Brown J, Shahab L. Association of quarterly prevalence of e-cigarette use with ever regular smoking among young adults in England: a time-series analysis between 2007 and 2018. Addiction. 2022 Aug;117(8):2283-2293. doi: 10.1111/add.15838. Epub 2022 Mar 9. PMID: 35263816; PMCID: PMC9543274.
    • Acknowledgment: The STS is currently primarily funded by Cancer Research UK (C1417/A14135; C36048/A11654; C44576/A19501), and has previously also been funded by Pfizer, GlaxoSmithKline and the Department of Health. J.B. and L.S. are members of SPECTRUM a UK Prevention Research Partnership Consortium (MR/S037519/1). UKPRP is an initiative funded by the UK Research and Innovation Councils, the Department of Health and Social Care (England) and the UK-devolved administrations and leading health research charities. No funders had any involvement in the design of the study, the analysis or interpretation of the data, the writing of the report or the decision to submit the paper for publication. The corresponding author had full access to all of the data and the final responsibility to submit for publication. E.B. and J.B. have received unrestricted research funding from Pfizer. E.B. and J.B. are funded by CRUK (C1417/A14135). L.S. has received honoraria for talks, an unrestricted research grant and travel expenses to attend meetings and workshops from Pfizer, and has acted as paid reviewer for grant awarding bodies and as a paid consultant for health-care companies. All authors declare there are no other relationships or activities that could appear to have influenced the submitted work.

2022: Is Adolescent E-Cigarette Use Associated With Subsequent Smoking? A New Look

• "Adjusting for a full set of confounders, including adolescents’ sociodemographic characteristics, exposure to tobacco users, susceptibility to smoking, and behavioral risk factors, we found that the association of ever e-cigarette use with subsequent smoking decreases substantially and even becomes non-significant in some waves, using both past 12-month and past 30-day smoking as outcomes. We believe this is the first study to report any non-significant findings, likely the result of the more comprehensive set of risk factor variables we included. As we demonstrate with the use of four models, each adding significant risk factor variables (and in turn decreasing the aOR of e-cigarette use), inclusion of logical risk factors is important to interpreting the association between adolescent vaping and subsequent smoking."
  • Citation: Sun R, Mendez D, Warner KE. Is Adolescent E-Cigarette Use Associated With Subsequent Smoking? A New Look. Nicotine Tob Res. 2022 Mar 26;24(5):710-718. doi: 10.1093/ntr/ntab243. PMID: 34897507; PMCID: PMC8962683.
    • Acknowledgment: The authors received no specific funding for this work.

2022: Is E-cigarette Use Associated With Persistence or Discontinuation of Combustible Cigarettes? A 24-Month Longitudinal Investigation in Young Adult Binge Drinkers

• "These findings suggest that concurrent or exclusive e-cigarette use is not a risk factor for the persistence or development of combustible tobacco use in this subpopulation, with dual-product use reflecting a transitional pattern away from combustible use, toward discontinuation."
  • Citation: Martinez-Loredo V, González-Roz A, Dawkins L, Singh D, Murphy JG, MacKillop J. Is E-cigarette Use Associated With Persistence or Discontinuation of Combustible Cigarettes? A 24-Month Longitudinal Investigation in Young Adult Binge Drinkers. Nicotine Tob Res. 2022 Jun 15;24(7):962-969. doi: 10.1093/ntr/ntac049. PMID: 35176769; PMCID: PMC9199943.
    • Acknowledgment: This study was supported by the National Institute on Alcohol Abuse and Alcoholism (R01AA024930; JGM and JM), the Canadian Institutes of Health Research (#365297; JM), the Peter Boris Chair in Addictions Research and the Canada Research Chair in Translational Addiction Research. JM is a principal in a private company, BEAM Diagnostics, Inc., but no commercial products fall within the scope of the study. No other authors have declarations.

2021: High School Seniors Who Used E-Cigarettes May Have Otherwise Been Cigarette Smokers: Evidence From Monitoring the Future (United States, 2009–2018)

• Conclusion: Youth e-cigarette use has increased rapidly, with high prevalence among nonsmoking youth. However, the decline in current smoking among 12th graders has accelerated since e-cigarettes have become available. E-cigarette use is largely concentrated among youth who share characteristics with smokers of the pre-vaping era, suggesting e-cigarettes may have replaced cigarette smoking.
  • Citation: Sokol NA, Feldman JM. High School Seniors Who Used E-Cigarettes May Have Otherwise Been Cigarette Smokers: Evidence From Monitoring the Future (United States, 2009-2018). Nicotine Tob Res. 2021 Oct 7;23(11):1958-1961. doi: 10.1093/ntr/ntab102. PMID: 33991190; PMCID: PMC8496467.
    • Acknowledgment: This work was supported by National Institute on Alcohol Abuse and Alcoholism T32 AA007459 to NAS.

2021: Has increased youth e-cigarette use in the USA, between 2014 and 2020, changed conventional smoking behaviors, future intentions to smoke and perceived smoking harms?

• Conclusion: "In two national samples of US youth, smoking prevalence declined by a sizeable relative percentage. Intent to smoke in the future and harm perceptions of smoking declined or remained unchanged while EC use increased. Results provide little evidence that EC use has increased conventional cigarette smoking among youth."
  • Citation: Sun T, Lim CCW, Stjepanović D, Leung J, Connor JP, Gartner C, Hall WD, Chan GCK. Has increased youth e-cigarette use in the USA, between 2014 and 2020, changed conventional smoking behaviors, future intentions to smoke and perceived smoking harms? Addict Behav. 2021 Dec;123:107073. doi: 10.1016/j.addbeh.2021.107073. Epub 2021 Jul 30. PMID: 34364109.
    • Acknowledgment: (Paywalled. Unable to see funding information) The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

2021: Association of genetic liability to smoking initiation with e-cigarette use in young adults: A cohort study

• Conclusion: "Our results indicate that there may be a shared genetic aetiology between smoking and e-cigarette use, and also with socioeconomic position, externalising disorders in childhood, and risky behaviour more generally. This indicates that there may be a common genetic vulnerability to both smoking and e-cigarette use, which may reflect a broad risk-taking phenotype."
• "The results also provide support for a shared genetic liability between e-cigarette use and smoking, which may have implications for policy; strict policies (e.g., bans), which aim to prevent e-cigarette use in order to reduce the risk of smoking initiation among youth and young adults, may not be effective. In fact, they may have the opposite effect; if young people are predisposed to both e-cigarette use and smoking but only cigarettes are available, this could increase their likelihood of smoking because it is the only option available to them."
  • Citation: Khouja JN, Wootton RE, Taylor AE, Davey Smith G, Munafò MR. Association of genetic liability to smoking initiation with e-cigarette use in young adults: A cohort study. PLoS Med. 2021 Mar 18;18(3):e1003555. doi: 10.1371/journal.pmed.1003555. PMID: 33735204; PMCID: PMC7971530.
    • Acknowledgment: GDS is a member of the Editorial Board of PLOS Medicine. All authors are members of the Integrative Epidemiology Unit at the University of Bristol which is funded by the UK Medical Research Council (https://mrc.ukri.org/; grant numbers MC_UU_0001/1&7). The UK Medical Research Council and Wellcome (grant number 102215/2/13/2) and the University of Bristol (http://www.bristol.ac.uk/) provide core support for the Avon Longitudinal Study of Parents and Children (ALSPAC). A comprehensive list of grants funding is available on the ALSPAC website (http://www.bristol.ac.uk/alspac/external/documents/grant-acknowledgements.pdf). This research was specifically funded by a Cancer Research UK (https://www.cancerresearchuk.org/) grant to AET (grant number C54841/A20491). This publication is the work of the authors (JNK, REW, AET, GDS and MRM) who will serve as guarantors for the contents of this paper. AET and MRM are also supported by the NIHR Bristol Biomedical Research Centre (https://www.bristolbrc.nihr.ac.uk/) at University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The sponsors played no role in the study design, data collection, data analysis, decision to publish, or preparation of the manuscript.

2021: Experimenting first with e-cigarettes versus first with cigarettes and transition to daily cigarette use among adolescents: the crucial effect of age at first experiment

• Conclusion: "Experimenting with e-cigarettes first (as opposed to tobacco first) appears to be associated with a reduction in the risk of daily tobacco smoking among French adolescents aged 17-18.5, but this risk varies negatively with age at experimentation, and early e-cigarette experimenters are at higher risk."
• PDF Full paper
  • Citation: Legleye S, Aubin HJ, Falissard B, Beck F, Spilka S. Experimenting first with e-cigarettes versus first with cigarettes and transition to daily cigarette use among adolescents: the crucial effect of age at first experiment. Addiction. 2021 Jun;116(6):1521-1531. doi: 10.1111/add.15330. Epub 2020 Dec 28. PMID: 33201553.
    • Acknowledgment: None declared.

2021: Trends in electronic cigarette use and conventional smoking: quantifying a possible 'diversion' effect among US adolescents

• Conclusion: "The current study uses simulation modeling to show that a net diversion effect is necessary to explain observed trends on US adolescent nicotine use. This is the first study to quantify the potential diversion effect of ECs, whereby they entirely prevent youth from using conventional smoking. This has important implications for the harm reduction potential of ECs. Future studies should extend this work by replicating findings in other settings, accounting for policy changes over time and incorporating forthcoming data on nicotine use trends."
  • Citation: Selya AS, Foxon F. Trends in electronic cigarette use and conventional smoking: quantifying a possible 'diversion' effect among US adolescents. Addiction. 2021 Jul;116(7):1848-1858. doi: 10.1111/add.15385. Epub 2021 Jan 19. PMID: 33394529; PMCID: PMC8172422.
    • Acknowledgment: This work was supported by the National Institute for General Medical Sciences (NIGMS) within the National Institutes of Health (NIH), grant number P20GM121341; by Direktoratet for internasjonalisering og kvalitetsutvikling i høgare utdanning (the Norwegian Agency for International Cooperation and Quality Enhancement in Higher Education; DIKU), grant number NNA‐2016/10023; and through a graduate research assistantship from the University of North Dakota (UND). This content is solely the work of the authors, and does not necessarily reflect the views of the NIH, NIGMS, DIKU or UND. The authors would also like to thank Dr Navid Ghaffarzadegan for feedback on an early version of the model. After this initial study was completed, both authors became affiliated with Pinney Associates, Inc., which provides consulting services on tobacco harm minimization to JUUL Labs, Inc. The content here precedes this conflict of interest, and as such neither JUUL nor Pinney Associates had any role in the conceptualization, design, analysis, interpretation or presentation of data, or in the decision to publish.

2021: Association of initial e-cigarette and other tobacco product use with subsequent cigarette smoking in adolescents: a cross-sectional, matched control study

• "In conclusion, this matched control analysis of NYTS data from 2014 to 2017 suggests that for adolescents initiation with e-cigarettes is associated with a reduced risk of subsequent cigarette smoking compared with initiators with other combustible and non-combustible tobacco products use, and propensity score matched adolescents without initial e-cigarette use. This suggests that, over the time period considered, e-cigarettes were unlikely to have acted as an important gateway towards cigarette smoking and may, in fact, have acted as a gateway away from smoking for vulnerable adolescents; this is consistent with the decrease in youth cigarette smoking prevalence over the same time period that youth e-cigarette use increased between 2014 and 2017.
• PDF of full paper
  • Citation: Shahab L, Beard E, Brown JAssociation of initial e-cigarette and other tobacco product use with subsequent cigarette smoking in adolescents: a cross-sectional, matched control studyTobacco Control 2021;30:212-220.
    • Acknowledgement: This project is funded by Cancer Research UK (C1417/A22962). All authors are members of the UK Centre for Tobacco and Alcohol Studies (UKCTAS), funded under the auspices of the UK Clinical Research Collaboration (MR/K023195/1). LS has received a research grant and honoraria for a talk and travel expenses from manufacturers of smoking cessation medications (Pfizer and Johnson & Johnson). JB has received unrestricted research funding from Pfizer to study smoking cessation.

2021: Relationships Between E-cigarette Use and Subsequent Cigarette Initiation Among Adolescents in the PATH Study: an Entropy Balancing Propensity Score Analysis

• "It is worth noting that the measure of past 30-day cigarette use is limited in terms of implications for understanding intensity of smoking and regular use. Past 30-day cigarette use is often referred to as a measure of current use, but it combines infrequent use (e.g., one or two occasions) with more frequent and even daily use. Thus, it does not distinguish between sporadic and more regular, dependent use. Small sample sizes precluded additional analyses based on other definitions of more frequent use. For example, in the study sample, few youth reported smoking cigarettes on more than 20 days (12 participants) or every day (7 participants) at Wave 3. Results of this study, therefore, should be interpreted with caution."
• Conclusion: "Use of e-cigarettes in nicotine and tobacco-naïve youth is associated with increased risk of subsequently using combustible cigarettes but the risk is an order of magnitude higher if they start with a combustible cigarette."
  • Citation: Xu S, Coffman DL, Liu B, Xu Y, He J, Niaura RS. Relationships Between E-cigarette Use and Subsequent Cigarette Initiation Among Adolescents in the PATH Study: an Entropy Balancing Propensity Score Analysis. Prev Sci. 2022 May;23(4):608-617. doi: 10.1007/s11121-021-01326-4. Epub 2021 Oct 31. PMID: 34719736; PMCID: PMC9129891.
    • Acknowledgment: This work was supported by a grant from the New York University (NYU) Research Challenge Fund Program. Research reported in this publication was also supported by the National Cancer Institute of the National Institutes of Health (NIH) and FDA Center for Tobacco Products (CTP) under Award Number U54CA229974. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the Food and Drug Administration. DC, BL, YX, and JH report no financial or other relationship relevant to the subject of this article. SX receives the research grants from NYU Research Challenge Fund and NIH/NCI supplement award through Grant U54CA229974. RN receives funding from the Food and Drug Administration Center for Tobacco Products via contractual mechanisms with Westat and the National Institutes of Health. The work presented here is independent of this funding, and does not represent the views or opinions of any government institutes or agencies.

2020: Does the gateway theory justify a ban on nicotine vaping in Australia?

• Conclusion: The association between nicotine vaping and cigarette smoking provides weak support for a gateway hypothesis. Smoking more often precedes vaping than vice versa, regular vaping by never-smokers is rare and the association is more plausibly explained by a common liability model. If there is a gateway effect, it is small at the population level because smoking prevalence has continued to decline despite an increased uptake of vaping in countries that allow it.
• PDF of full paper
  • Citation: Mendelsohn CP, Hall W. Does the gateway theory justify a ban on nicotine vaping in Australia? Int J Drug Policy. 2020 Apr;78:102712. doi: 10.1016/j.drugpo.2020.102712. Epub 2020 Mar 4. PMID: 32145594.
    • Acknowledgment: Colin Mendelsohn: I have received funding from Pfizer Australia, Johnson & Johnson Pacific and Perrigo Australia for teaching, consulting and conference expenses. I have never received payments from electronic cigarette or tobacco companies. I am a Board member of the Australian Tobacco Harm Reduction Association (ATHRA), a health promotion charity. ATHRA has received unconditional funding for establishment costs from small Australian vape businesses. Vape industry funding has not been accepted since March 2019.

2020: The Relationship Between Electronic Cigarette Use and Conventional Cigarette Smoking Is Largely Attributable to Shared Risk Factors

• "Taken together, the current findings fail to support the gateway theory, which predicts that e-cigarettes will promote the initiation as well as continued21,31,42 and heavier43 smoking of conventional cigarettes."
  • Citation: Kim S, Selya AS. The Relationship Between Electronic Cigarette Use and Conventional Cigarette Smoking Is Largely Attributable to Shared Risk Factors. Nicotine Tob Res. 2020 Jun 12;22(7):1123-1130. doi: 10.1093/ntr/ntz157. PMID: 31680169; PMCID: PMC7291806.
    • Acknowledgment: This work was supported by an Early Career Grant Award to AS from the University of North Dakota, the National Institute on Drug Abuse (grant number L40 DA042431), and the National Institute for General Medical Sciences (grant number 1P20GM121341-01).

2020: Trends in Tobacco Use Among Adolescents by Grade, Sex, and Race, 1991-2019

• This cross-sectional study suggests that, despite the increase in the prevalence of e-cigarette use among adolescents between 2011 and 2019, the prevalence of cigarette and smokeless tobacco use has decreased more rapidly during the same period compared with earlier years.
• Link to PDF on study page
  • Citation: Meza R, Jimenez-Mendoza E, Levy DT. Trends in Tobacco Use Among Adolescents by Grade, Sex, and Race, 1991-2019. JAMA Netw Open. 2020;3(12):e2027465. doi:10.1001/jamanetworkopen.2020.27465
    • Acknowledgement: Research reported in this publication was supported by award U54CA229974 from the National Cancer Institute of the National Institutes of Health and the US Food and Drug Administration Center for Tobacco Products.

2020: Electronic cigarettes, nicotine use trends and use initiation ages among US adolescents from 1999 to 2018

• Conclusion: "Electronic cigarettes may have offset conventional smoking among US adolescents between 2010 and 2018 by maintaining the total nicotine use prevalence and diverting them from more harmful conventional smoking. Additionally, electronic cigarette users appear to initiate at older ages relative to conventional smokers, which is associated with lower risk."
  • Citation: Foxon F, Selya AS. Electronic cigarettes, nicotine use trends and use initiation ages among US adolescents from 1999 to 2018. Addiction. 2020 Dec;115(12):2369-2378. doi: 10.1111/add.15099. Epub 2020 May 19. PMID: 32335976; PMCID: PMC7606254.
    • Acknowledgment: This work was supported by the National Institute of General Medical Sciences of the National Institutes of Health under grant number 1P20GM121341. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or NIGMS.

2020: Does e-cigarette experimentation increase the transition to daily smoking among young ever-smokers in France?

• Conclusion: "Our results show that among French ever smokers aged 17, those who had experimented with e-cigarette were less likely to later transition to daily smoking than those who had not. This was the case even when e-cigarette was tried before initiating smoking, in contradiction with the gateway hypothesis."
  • Citation: Chyderiotis S, Benmarhnia T, Beck F, Spilka S, Legleye S. Does e-cigarette experimentation increase the transition to daily smoking among young ever-smokers in France? Drug Alcohol Depend. 2020 Mar 1;208:107853. doi: 10.1016/j.drugalcdep.2020.107853. Epub 2020 Jan 11. PMID: 31958678.
    • Acknowledgment: This work was supported by the French Cancer League (La Ligue contre le cancer) as part of the PETAL research program on adolescent smoking. The content is solely the responsibility of the authors.

2020: Use of e-cigarettes and smoked tobacco in youth aged 14–15 years in New Zealand: findings from repeated cross-sectional studies (2014–19)

• Conclusion: "The overall decline in smoking over the past 6 years in New Zealand youth suggests that e-cigarettes might be displacing smoking."
  • Citation: Walker N, Parag V, Wong SF, Youdan B, Broughton B, Bullen C, Beaglehole R. Use of e-cigarettes and smoked tobacco in youth aged 14-15 years in New Zealand: findings from repeated cross-sectional studies (2014-19). Lancet Public Health. 2020 Apr;5(4):e204-e212. doi: 10.1016/S2468-2667(19)30241-5. Epub 2020 Jan 22. PMID: 31981489.
    • Acknowledgment: NW, VP, and CB report grants from New Zealand Ministry of Health, during the conduct of the study; grants from Pfizer, and the Health Research Council of New Zealand, outside of the submitted work; and have undertaken a trial of e-cigarettes used with and without nicotine patches for smoking cessation (with e-cigarettes purchased from a New Zealand e-cigarette online retailer (NZVAPOR, https://www.nzvapor.com/), e-liquid purchased from Nicopharm, Australia (https://www.nicopharm.com.au/), and nicotine patches supplied by the New Zealand Government via their contract with Novartis (Sydney, Australia). NZVAPOR also provided, (at no cost to trial participants) online and phone support regarding use of the e-cigarettes. Neither NZVAPOR nor Nicopharm have links with the tobacco industry. None of the aforementioned parties had any role in the design, conduct, analysis, or interpretation of the trial findings, or writing of the resulting publication. CB also reports personal fees from Johnson and Johnson, grants from Cure Kids Foundation, and other funds from Sanitarium outside of the submitted work. SFW reports grants from New Zealand Ministry of Health, during the conduct of the study. RB, BY, and BB declare no competing interests.

2019: Examining the relationship of vaping to smoking initiation among US youth and young adults: a reality check

• Results: "There was a substantial increase in youth vaping prevalence beginning in about 2014. Time trend analyses showed that the decline in past 30-day smoking prevalence accelerated by two to four times after 2014. Indicators of more established smoking rates, including the proportion of daily smokers among past 30-day smokers, also decreased more rapidly as vaping became more prevalent."
• Conclusion: "The inverse relationship between vaping and smoking was robust across different data sets for both youth and young adults and for current and more established smoking. While trying electronic cigarettes may causally increase smoking among some youth, the aggregate effect at the population level appears to be negligible given the reduction in smoking initiation during the period of vaping’s ascendance."
  • Citation: Levy DT, Warner KE, Cummings KM, et alExamining the relationship of vaping to smoking initiation among US youth and young adults: a reality checkTobacco Control 2019;28:629-635.
    • Acknowledgment: RB, KMC, GTF, MLG, DH, DTL and JFT received funding from the National Cancer Institute under grant P01CA200512. MLG was a member of the National Academies of Sciences, Engineering, and Medicine (NASEM) Committee on the Review of the Health Effects of Electronic Nicotine Delivery Systems who wrote the report. The report was funded by the Food and Drug Administration (FDA), but the FDA was not involved in the drafting or review of the NASEM Report or this manuscript. The policy implications written in this manuscript are the views of the authors and do not necessarily represent the views of the other members of the Committee, the NASEM or the FDA. MLG also received a research grant and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation medications. KMC and DH have served as an expert witness in litigation against the cigarette industry.

2019: E-cigarette use and onset of first cigarette smoking among adolescents: An empirical test of the ‘common liability’ theory

• Conclusion: "Findings from this study provide supportive evidence for the ‘common liability’ underlying observed associations between e-cigarette use and smoking onset."
  • Citation: Cheng HG, Largo EG, Gogova M. E-cigarette use and onset of first cigarette smoking among adolescents: An empirical test of the 'common liability' theory. F1000Res. 2019 Dec 13;8:2099. doi: 10.12688/f1000research.21377.3. PMID: 32724557; PMCID: PMC7366034.
    • Acknowledgment: The study is supported by Altria Client Services LLC. All authors are full-time employees of Altria Client Services LLC.

2019: The Impact of Electronic Cigarettes on Cigarette Smoking By Americans and Its Health and Economic Implications

• In this study, we examined the growing use of electronic cigarettes and its implications. The wide use of e-cigarettes is a very recent development, and issues regarding their long-term effects and significance cannot be fully analyzed at this time. Using CDC and other data covering the last decade, however, we examined the relationship between the recent sharp increase in e-cigarette use among Americans and the contemporaneous acceleration in the declining rate of cigarette smoking. We found that the sharp increase in e-cigarette use across many groups can explain as much as 70 percent of the accelerating decline in smoking rates. We also found no reasonable evidential basis for concerns that e-cigarettes are a gateway to cigarette smoking. We further found that e-cigarettes are highly effective in helping people stop smoking cigarettes.
  • Citation: The Progressive Policy Institute

2019: Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review

• "Data from five surveys in US/UK youths all show that, regardless of sex and age, smoking prevalence in 2014–2016 declined faster than predicted by the preceding trend, suggesting the absence of a substantial gateway effect."
  • Citation: Lee PN, Coombs KJ and Afolalu EF. Considerations related to vaping as a possible gateway into cigarette smoking: an analytical review [version 3; peer review: 2 approved]. F1000Research 2019, 7:1915 doi.org/10.12688/f1000research.16928.3
    • Acknowledgment: Competing interests: PNL and KJC consult for various tobacco companies. EFA is a current employee of Philip Morris International. Grant information: This work was supported by PMI R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, CH-2000 Neuchâtel, Switzerland.

2019: Investigating gateway effects using the PATH study

• "In considering whether a true important gateway effect exists, one should note the lack of any increase in the US in cigarette smoking prevalence following the rise in vaping (Levy et al., 2019), and the fact that, in the PATH study, considerably more (279 vs. 79) Wave 1 cigarette only smokers took up e-cigarettes by Wave 2, than Wave 1 e-cigarette only users who took up smoking. Despite any possible gateway effect, introducing e-cigarettes may have reduced overall youth smoking prevalence."
• Conclusion: "The results presented, based on Waves 1 and 2, strongly suggest that reported estimates of the gateway effect (Soneji et al., 2017) are much too high. Indeed, it is not completely clear whether vaping actually increases subsequent uptake of cigarette smoking if potential confounding effects were to be fully accounted for."
  • Citation: Lee PN and Fry JS. Investigating gateway effects using the PATH study [version 2; peer review: 2 approved]. F1000Research 2019, 8:264 (https://doi.org/10.12688/f1000research.18354.2)
    • Acknowledgment: Competing interests: Peter Lee, director of P N Lee Statistics and Computing Ltd, is an independent consultant to a number of tobacco companies. John Fry is a former employee of Peter Lee’s company. Grant information: Financial support was provided by Philip Morris Products SA, through Project Agreement No. 19 with P N Lee Statistics and Computing Ltd. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

2018: How can we protect youth from putative vaping gateway effects without denying smokers a less harmful option?

• "It is reassuring that smoking prevalence among young people in the United Kingdom and United States has declined as vaping has increased in these countries 11-13. This suggests that the fear that vaping would increase recruitment of youth to cigarette smoking and lead to higher youth smoking prevalence has not materialized."
  • Citation: Gartner C. How can we protect youth from putative vaping gateway effects without denying smokers a less harmful option? Addiction. 2018 Oct;113(10):1784-1785. doi: 10.1111/add.14126. Epub 2018 Jan 11. PMID: 29327489.
    • Acknowledgment: C.G.’s salary is supported by a NHMRC Career Development Fellowship (GNT1061978).

2017: Gateway effects and electronic cigarettes

• " The gateway theory is not compatible with either (1) the decrease in smoking prevalence observed in adolescents in countries where vaping increased or (2) an increase in smoking among teenagers after age restrictions were imposed on e-cigarette purchases. A spurious gateway effect can be produced artificially by mathematical models in which a propensity to use substances is correlated with opportunities to use substances. Finally, neither nicotine medications nor smokeless tobacco produce gateway effects. Available data are compatible with a common liability model in which people who are liable to use nicotine are more likely to use both e-cigarettes and cigarettes."
• Conclusion: "Despite its weaknesses and scant empirical support, the gateway theory of smoking initiation has had enormous political influence. Policies based on this theory will not have the intended effects if the association between vaping and smoking is explained by common liabilities."
• PDF Full paper
  • Citation: Etter JF. Gateway effects and electronic cigarettes. Addiction. 2018 Oct;113(10):1776-1783. doi: 10.1111/add.13924. Epub 2017 Aug 7. PMID: 28786147.
    • Acknowledgment:No external funding; no competing interests. J.F.E.’s salary is paid by the University of Geneva.

2017: Evaluating the mutual pathways among electronic cigarette use, conventional smoking and nicotine dependence

• Conclusion: "Nicotine dependence is not a significant mechanism for e-cigarettes’ purported effect on heavier future conventional smoking among young adults. Nicotine dependence may be a mechanism for increases in e-cigarette use among heavier conventional smokers, consistent with e-cigarettes as a smoking reduction tool. Overall, conventional smoking and, to a lesser extent, its resulting nicotine dependence, are the strongest drivers or signals of later cigarette and e-cigarette use."
  • Citation: Selya AS, Rose JS, Dierker L, Hedeker D, Mermelstein RJ. Evaluating the mutual pathways among electronic cigarette use, conventional smoking and nicotine dependence. Addiction. 2018 Feb;113(2):325-333. doi: 10.1111/add.14013. Epub 2017 Sep 25. PMID: 28841780; PMCID: PMC5760290.
    • Acknowledgment: Grants and funding, L40 DA042431/DA/NIDA NIH HHS/United States, P01 CA098262/CA/NCI NIH HHS/United States, P30 DK092949/DK/NIDDK NIH HHS/United States, P50 DA039838/DA/NIDA NIH HHS/United States

2015: How does electronic cigarette access affect adolescent smoking?

• Across the board, this paper's analyses find that reducing e-cigarette access increases smoking among 12 to 17 year olds.
  • Citation: Friedman AS. How does electronic cigarette access affect adolescent smoking? J Health Econ. 2015 Dec;44:300-8. doi: 10.1016/j.jhealeco.2015.10.003. Epub 2015 Oct 19. PMID: 26583343.
    • Acknowledgment: I am grateful to David Cutler, Richard Frank, Claudia Goldin, Frank Sloan, Jody Sindelar, Martin Anderson, Sebastian Bauhoff, Shivaani Prakash, Mark Schlesinger, and Sam Richardson for helpful comments and discussion, and to the Radcliffe Institute for Advanced Study, for fellowship funding that helped support this research.

2014: Youth experimentation with e-cigarettes: another interpretation of the data

• "Cross-sectional surveys provide us with valuable descriptive information that prompts us to watch carefully how many youth are using tobacco products on e-cigarettes but do not provide explanations for use. Prematurely overinterpreting or Misinterpreting data, perhaps based on ideology, does not help the cause of Tobacco Control or Public Health. Implying causal explanations in the absence of appropriate data can lead the health care community and policy makers down false paths on the road to relieving the horrific toll imposed on society by addictive and lethal combustible cigarettes."
  • Citation: Niaura RS, Glynn TJ, Abrams DB. Youth experimentation with e-cigarettes: another interpretation of the data. JAMA. 2014 Aug 13;312(6):641-2. doi: 10.1001/jama.2014.6894. PMID: 25117133.
    • Acknowledgment: No COI reported.

Letters/Testimony

2021: Testimony in Netherlands pertaining to a potential flavour / flavor ban: Regulation of e-cigarette flavours – a response

• Signed by 24 experts from around the world
• Covers 12 key points, including the theory of a gateway effect

Articles/Blogs

• A collection of articles, press releases, Op-Eds, and blog posts about products being a gateway to smoking. Is there proof? How are concerns about gateway being used to influence policy?

2024: Study: Heated Tobacco Products Increase Smoking Cessation Chances; 99.4% of Users Switched from Traditional Cigarettes

• "They also affirmed that there is no evidence that heated tobacco products serve as a gateway to starting smoking."

2024: Why We Need World Vape Day More Than Ever

• (Talking about misinformation.) "Just since April, the following claims have earned community notes: People who vape have high levels of uranium in their urine; vaping causes seizures; vaping harms your lungs within days; vaping is a gateway to smoking, all nicotine products are extremely damaging to health; and vapes cannot be recycled."

2024: It’s Critically Important to Tell Women the Truth About Nicotine

• "Dire warnings based on debunked myths backed by questionable science continue to make headlines, claiming people who vape nicotine will get popcorn lung, COVID, or “EVALI.” Studies full of methodological flaws portray vaping as a “gateway” to smoking. Or claim that vaping causes cancer, liver disease, myocardial infarction, COPD, and other diseases. Experts are kept busy evaluating these studies and submitting critiques of some of the most egregious papers, and their work has led to some studies being retracted."

2023: Is vaping a gateway to smoking?

• "The gateway theory predicts that vaping will increase smoking rates in young people. However, we are seeing the opposite of this. In countries where vaping is readily available such as the UK, US and New Zealand, the decline in youth smoking rates has accelerated."

2023: French Parliament Unanimously Backs Disposable Vapes Ban

• “This clearly shows that large [youth] experimentation of vaping does not lead to a collective ‘gateway effect’ to smoking,” he said. “In contrast, vaping could have a diversion effect.”

2023: France to Ban Disposable Vapes This Year in “Dangerous” Move

• "But the now-familiar “gateway theory” is contradicted by large-scale evidence. As recent commentary in the International Journal of Drug Policy noted, if the theory accurately described the population-level relationship between youth vaping and smoking, you’d expect vaping increases to produce higher youth smoking rates. On the contrary, rises in youth vaping in the United States, the United Kingdom and New Zealand “have been accompanied by an accelerated decline in smoking.”

2023: The Slow-Moving Train Wreck of Australian Vaping Policy

• "A case study is how Health Minister Butler frames his proposed harsher crackdown on vaping as youth protection. Despite the evidence to the contrary, he repeatedly claims that “vaping is a gateway to smoking.” He states that, “Vaping is creating a whole new generation of nicotine dependency in our community,” when Australian studies show that among youth who don’t smoke, less than 2 percent vape nicotine weekly or more."

2023: With youth vaping hitting a 10-year low, policymakers should focus on harm-reduction

• "Youth vaping in the United States has hit a 10-year low, according to new data from the Centers for Disease Control and Prevention (CDC). The so-called youth vaping epidemic appears to be a thing of the past, with historical lows in youth smoking dispelling fears of a gateway effect."

2023: No “Epidemic,” But CDC Delivers New Dose of Youth-Vaping Alarmism

• "In “What Are the Health Risks of Vaping for Youth?” the CDC states that youth are more susceptible than adults to nicotine addiction, which “may put youth at a risk for addiction to other substances in the future”—a version of the “gateway theory” that simply isn’t supported by meaningful evidence."

2023: Venezuela Bans All Vape Products, in Latest Blow to THR in Latin America

• "In 2022, the board of Brazil’s National Health Regulatory Agency (ANVISA) unanimously decided to uphold the country’s vape ban. They justified this with a series of false claims, saying that vapes are not shown to reduce harm and are a “gateway” to cigarette smoking for young people."

2023: It’s Time to Change the Way We Look at Youth Vaping

• "Young people who try vaping are more likely to try smoking. But this simply tells us that people who are more likely to try nicotine products are also more likely to try other nicotine products. There is no evidence that vaping causes people to smoke if they would not otherwise have done so (the “gateway theory”)."

2023: Situation Looks “Dire,” Say Opponents of Oregon Vape Flavor Ban

• "In commentary published by the Journal of the American Medical Association in March, for example, the director of the Rutgers Center for Tobacco Studies, Cristine Delnevo, wrote that “concerns about a gateway effect and a potential increase in youth cigarette use following the introduction of e-cigarettes to the US market are not supported by the data.”

2023: Is Canada Turning the Corner on Tobacco Harm Reduction?

• "The justifications were a highly debatable belief that flavors increase youth vaping, and the notion, refuted by population-level data, that vaping is a “gateway” into cigarette smoking."

2023: Anti-Vaping Sensors and CCTV in Schools: Is the UK Joining In?

• “At the population level,” she concluded, “e-cigarettes do not appear to be a gateway to cigarette smoking.” ... "Yet in justifying the measures at Baxter College, Carpenter, like many international public health figures, cited this supposed “gateway” effect."

2023: Taiwan Is About to Ban the Use of Nicotine Vapes

• "...the government has listed many reasons for the ban—alleging that vaping is bad for health, causes “EVALI,” includes cannabis use, has “gateway” potential, leads to a youth epidemic, and so forth."

2022: The Half-Truth Initiative: How an Anti-Smoking Group Lost Its Way

• "For example, Truth claims that vaping is a gateway to smoking. “Young people who had ever used e-cigarettes had seven times higher odds of becoming smokers one year later compared with those who had never vaped,” it says. But other studies find that “vaping likely diverts more young people from smoking than encourages them to smoke,” according to a paper by 15 past SRNT presidents. That paper also notes that “smoking among young people has declined at its fastest rate ever during vaping’s ascendancy,” making the gateway claim highly unlikely."

2022: Researchers Expose the Pitiful Quality of Highly Cited Vaping Studies

• "Among others, the researchers debunked studies that claimed to demonstrate the so-called “gateway effect,” which has been widely used to scare the public into believing that vaping nicotine leads to combustible tobacco use. “The studies we analyzed lacked sound research methods, and as such, could not reliably establish causation or identify a gateway effect,” the authors wrote."

2022: End Vape Misinformation, Tobacco Control Experts Urge Surgeon General

• "Cliff Douglas, one of the coauthors and the director of the University of Michigan Tobacco Research Network, told Filter. “The surgeon general’s website implies, for example, that e-cigarette use causes young people to become smokers, but this is strongly contradicted by widely available evidence"...The authors argue, therefore, that Surgeon General Vivek Murthy has helped perpetuate the myth that vapes are a “gateway” to cigarettes. In fact, they’re a well-trodden path to smoking cessation."

2022: Supreme Court Refuses to Block California’s Nicotine Flavor Ban

• " “Flavored tobacco products have hooked a new generation of young smokers at a time when tobacco is already the number one preventable killer in the United States,” the attorney general of California, Rob Bonta, said in a press statement. Vapes’ inclusion as “tobacco products” in US nomenclature means that he wrongly implied vaping is a “gateway” to smoking. And cigarette smoking is the number one cause of preventable death—not tobacco per se, which is also found in harm reduction products like snus or “heat-not-burn” devices. "

2022: California Votes to Ban Sales of Almost All Flavored Nicotine Products

• "Vaping nicotine, however, has in no way been established as a “gateway” to combustible cigarette use. Actually, the opposite looks to be true: A study published in JAMA Pediatrics by the Yale public health researcher Abigail Friedman showed that teenagers were more likely to start smoking than those in other US school districts after San Francisco’s flavored vape ban passed; another study by Brown’s Natasha Sokol and Harvard’s Justin Feldman, which appeared in Nicotine & Tobacco Research, suggested that youth who do vape are typically those who would have been smoking were vapes unavailable."

2022: How to Respond Sensibly to an Increase in Youth Vaping

• "The ASH briefing went on to firmly refute myths that had been promoted by garish headlines. It stated categorically that, “Disposable vapes DO NOT contain as much or more nicotine as a packet of 20 cigarettes.” It added that, “There is NOT strong evidence that vaping is a gateway into smoking,” with no evidence for the “gateway hypothesis.” And it asserted, correctly, that “An outbreak of serious respiratory disease (known as ‘EVALI’) in the US in 2019 WAS NOT caused by vaping nicotine.” "

2022: Why Aren’t We Celebrating the End of Teenage Smoking?

• "I believe this raises serious questions about the motivations of health “experts” who continue to insist that teen vaping is a gateway to smoking, that we’re in the midst of a teen vaping epidemic, and that a “whole new generation” is now “addicted to nicotine.” All of those claims bear an uncanny resemblance to 1930s Reefer Madness."

2021: Canada’s Proposed Nicotine Cap for Vapes Earns Sharp Criticism

• "However, the researchers also determined that in Canada, unlike in the US, there had also been a significant uptick in youth smoking—lending credence to an often-debunked and challenged theory of a “gateway” from vapes to combustible cigarettes. The problem was—as Clive Bates, a public health consultant and the former director of Action on Smoking and Health in the UK noted at the time—the BMJ paper’s figures were wrong. Almost exactly a year later, the journal issued a correction, seemingly hidden in a statistical supplement. Nonetheless, the controversial paper—critiqued in tobacco control and harm reduction circles—has apparently made an impact."

2020: Study: Vaping Looks Like a Gateway Out of—Not Into—Smoking

• “Just like sugar substitutes help people to reduce their sugar intake, e-cigarettes help people to quit smoking,” Chaplia continued. “We don’t blame sugar substitutes for increased sugar consumption, yet doing so for e-cigarettes seems to be acceptable.”

2020: Most Young People Do Not Vape, and Even Fewer Vape Regularly

• "The faster drop in smoking suggests vaping is helping displace youth use of much more deadly smoking—a net harm reduction benefit to the population as a whole,” said David Abrams..."

2020: Dismantling NY Mag’s Disgraceful Hit-Job on Vaping

• "Myers warns, “We now know conclusively that kids who start using e-cigarettes are far more likely to go onto smoke cigarettes.” Actually, the idea that e-cigarettes are a gateway to smoking has been conclusively debunked."

2019: The great American youth vaping epidemic. Really?

• "Although it is possible to identify associations between prior vaping and subsequent smoking, they may not be causal. But a further issue is just how few adolescents these relationships apply to."

2019: Unfounded E-Cigarette Panic Puts Public Health at Risk

• "More important, the latest CDC data reveal nothing about underage smoking, which is the single most important data point in evaluating the harms or benefits of teenage vaping. Since the introduction of e-cigarettes to the U.S. market, adolescent use of cigarettes has more than halved, from 15.8 percent in 2011 to 7.6 percent in 2017. Rather than e-cigarettes acting as a gateway to smoking, as is assumed by government and advocacy groups, this indicates that teenage e-cigarette use is more likely diverting would-be smokers toward a less harmful means of nicotine consumption and potentially away from nicotine consumption altogether."

2019: Addicted to fear, the FDA is hurtling toward a historic mistake

• "In essence, the FDA is planning a massive regulatory onslaught against products that are significantly safer than cigarettes based on an unproven hypothesis and an alleged gateway that is as poorly defined as it is elusive."

2019: New Zealand Government Initiative Shows Welcome Support for Tobacco Harm Reduction

• "Salesa and the website challenge popular criticisms of vaping. While recognizing that vaping products are “not harmless to health,” but instead simply “much less harmful than smoking,” Salesa rejects the idea, popular in the United States, that providing tobacco harm reduction information will encourage young people to take up vaping. “Some people worry that vaping might be a ‘gateway’ to smoking for young people, but there is no clear evidence for this.” "

2019: Prohibition and Misinformation: Australia’s Tobacco Harm Reduction Fail

• "Queensland Health also makes the claim—familiar to US observers—that vaping is a “gateway” for young people to start smoking. This has not been borne out by international experience."

2019: FDA Cherry Picks Science in “Magic” Anti-Vaping Campaign

• "On July 22, the US Food and Drug Administration announced the launch of two new videos promoting the message that vaping is a “gateway” to smoking. It’s part of the agency’s ongoing youth-vaping prevention campaign, “The Real Cost,” that has repeatedly leaned on fear-mongering...It alludes to the findings of one study from February 2019 that observed, “prior e-cigarette use was associated with more than four times the odds of ever cigarette use.” ... The researchers also noted that they “cannot establish causal relations or rule out the possibility of residual confounding by underlying risk-taking propensities,” and thus their findings “should be interpreted with caution.” "

2018: Expert Debunks Vaping ‘Gateway’ Myth, Ripping ‘Bad Science In Service Of Bad Theories’

• " A leading expert in the field of tobacco harm reduction is criticizing a wave of recent studies claiming electronic cigarettes are a “gateway” to smoking as “bad science in service of bad theories.” "

2018: The War on Nicotine Pits Prejudice Against Public Health

• "This nicotine war carries eerie echoes from the ruinous war on illegal drugs. Taking several pages out of the “Reefer Madness” playbook, the tobacco control establishment’s “Vaper Madness” deploys tactics including: specious protect-the-children arguments, “gateway” claims, unfounded exaggerations of risks, and junk science."

2017: Vaping Study Sinks Claims E-Cigarettes Are Hooking Teens On Tobacco

• The hysteria over vaping allegedly serving as a gateway to smoking for teens is unfounded and goes against scientific evidence, according to a new study.

2017: Feds Owe the Public 'Corrective Statements' on Vaping

• "In the U.S., by contrast, former Surgeon General Vivek Murthy's 2016 report on youth vaping raised a range of concerns, including the risk of a “gateway” effect whereby teen vapers allegedly progressed to smoking. That would be a grave concern if it were happening – but it’s not."

2017: Huffington Post author claims vaping could be gateway to drugs and crime

• "E-cigarettes are under fire for being a possible gateway to a life of crime and crippling addiction to hard drugs in one of the most lurid attacks on the products yet."
• “E-cigs can easily become a gateway to trying and developing an addiction to more serious drugs,” warns Sudip Bose, a physician, in an article for the Huffington Post. “Addiction correlates to crime. People need to feed their habit, they break into homes to steal things to resell, they commit robberies on the streets, all to get money to feed their addiction.”
• "The jump from experimenting with e-cigarettes, to nicotine addiction, to hard drugs and crime stretches Bose’s credibility to a breaking point: There is precisely zero evidence for any gateway effect of e-cigarettes on drugs or crime, and none is cited in the article."
• "Not only that, but there is no evidence that vaping acts as a gateway to regular tobacco smoking despite the best efforts of some anti-e-cigarette campaigners."

2017: Merchants Of Doubt: How Public Health Uses Tobacco Tactics Against E-Cigarettes

• "Several years of the background noise of claim and counterclaim has contaminated the public's understanding of relative risk and harm reduction. Constant panics of teen vaping and unproven "gateway" effects take prominence in media coverage over the potential benefits of smokers switching to vaping."

2017: Vaping Is Not a Gateway to Smoking, New Study Shows

• "But far from being the smoking gun finally proving e-cigarettes are a gateway to their tobacco-filled rivals, the study itself finds there is still absolutely no evidence of a gateway effect from vaping to regular cigarette use."

2016: New CDC Report on E-Cigarettes Shatters Gateway Myth, Suggests Shift from Hazardous Smoking to Much Safer Vaping among Youth

• "However, today's CDC report reveals that something very different appears to be occurring. It appears that rather than serving as a gateway toward cigarette smoking, e-cigarettes may actually be acting as a diversion away from cigarettes."

2015: World Lung Foundation Disseminates Conclusion that E-Cigarettes are a Gateway to Smoking Based on a Bogus Study

• "More importantly, nowhere in the study does it conclude that e-cigarettes are a gateway to smoking."
• "However, the most embarrassing and irresponsible behavior in this story is that of the World Lung Foundation, which disseminated the conclusion that e-cigarettes are a gateway to smoking based on the barely comprehensible quote of a single kid in Fife."

2015: 2014 Anti-Smoking Myth of the Year Award Goes to CDC, Dr. Stan Glantz, and Dr. Michael Fiore

• "...for publicly spreading the myths that electronic cigarettes have been found to be a gateway to smoking..."

2015: Is “ecigs are a gateway” the new “addiction”? (i.e., fiercely debated in the absence of defining the term)

• "The fatal flaw, as with all other studies that are cited as showing there is a gateway effect, is confounding: The same type of people who are more likely to try/use e-cigarettes are more likely to try/use cigarettes"

2015: JAMA paper finds some adolescents experiment with stuff – so what?

• "The Journal of the American Medical Association has published a paper looking at what happens to 14 year old adolescents from Los Angeles County schools who had never smoked tobacco products, but had used an e-cigarette at least once. Unsurprisingly, some of these teenagers go on to smoke. Unsurprisingly, some commentators will claim this study shows a gateway effect. Before a new moral panic takes hold, there are three main points to draw out..."

2014: New Study Refutes Claim that Electronic Cigarettes are a Gateway to Smoking

• "This study found only three students, in a sample of 1,300, who had initiated nicotine use with e-cigarettes and progressed to smoking...These findings refute the claim that electronic cigarettes are a gateway to smoking. "

2014: Glantz Tells Public There is No Question that E-Cigarettes are a Gateway to Smoking, But Today's Monitoring the Future Data Show the Opposite

• "It is clear that experimentation with electronic cigarettes among youth has increased dramatically from 2011 to 2014. But despite this dramatic increase, the prevalence of current smoking among youth decreased dramatically. And the sharpest decline in smoking occurred concurrently with the largest increase in electronic cigarette use."

2014: Columbia Scientists Claim that E-Cigarettes May Be Gateway to Illicit Drug Use and Addiction

• "There is no justification for drawing this sweeping conclusion based solely on studies of mouse brains, without a shred of clinical or epidemiologic evidence that suggests e-cigarettes serve as a gateway to smoking or illicit drug addiction."

2014: Spurred On By CDC/Glantz Propaganda, Two U.S. Senators Claim that Electronic Cigarettes are a Gateway to Smoking

• "The assertions by the CDC, by Stan Glantz, by Senator Blumenthal, and by Senator Schumer are completely unsubstantiated by actual scientific data. In fact, there is no scientific evidence to support the conclusion that they have all disseminated to the public: that electronic cigarettes are a gateway to smoking."

2013: Cambridge Public Health Department Follows the CDC's Lead, Claims that Electronic Cigarettes are a Gateway to a Lifetime of Tobacco Use

• "There is, in fact, no evidence that electronic cigarettes serve as a gateway to a lifelong tobacco habit. In fact, there is not even any evidence that electronic cigarettes serve as a gateway to a short-lived tobacco habit. The only study to examine this hypothesis found that electronic cigarettes are not currently serving as a gateway to cigarette smoking among young people."

2013: E-Cigarettes May Not Be Gateway to Smoking: Study

• "It didn't seem as though it really proved to be a gateway to anything," said Wagener, who presented his findings at a meeting of the American Association for Cancer Research, in National Harbor, Md."

2013: We need to talk about the children – the gateway effect examined

• "When to you ever hear politicians with a rally cry: “we must protect the grumpy old men!”. We shouldn’t take measures that harm this group or fail to provide them with options because of largely groundless fears about gateway effects and young people starting. So I think the ban on snus, which is largely justified on gateway grounds is utterly reprehensible – and anything done to e-cigs to make them less attractive to young people that also makes them less attractive to older people is just as bad."