Myth: Alternative nicotine products are a gateway to smoking

The Gateway Hypothesis

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.

Articles/Blogs/Op-Eds

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."

Vaping Up < - > Smoking Down

Papers

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.

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. https://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.

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

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

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

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

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

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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

2020: Association of initial e-cigarette and other tobacco product use with subsequent cigarette smoking in adolescents: a cross-sectional, matched control study

• Conclusion: 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.
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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

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

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

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2019: The Relationship Between Electronic Cigarette Use and Conventional Cigarette Smoking Is Largely Attributable to Shared Risk Factors

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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.
• Finally, we analyzed the impact of the sharp increase in e-cigarette use and the accelerating decline in cigarette smoking on healthcare costs and economic productivity. We found that while e-cigarette users incur lower healthcare costs than cigarette smokers or ex-smokers, the longer lifespans of e-cigarette users and ex-smokers who used e-cigarettes to quit smoking result in higher lifetime healthcare costs. However, we also found that the value of the additional years of life associated with using e-cigarettes instead of smoking is much greater than the additional healthcare costs. Lastly, we found that the increase in e-cigarette use and the associated reduction in smoking rates results in large productivity benefits, mainly from lower rates of illness.
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Articles/Blogs

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: 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."

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.”

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.” "

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.