There is little evidence that e-cigarettes are a gateway to smoking, while around 50,000 smokers are estimated to quit smoking per year because of e-cigarette use.
A new study of cigarette and e-cigarette use among 16 to 24-year-olds over the past 11 years in England published in scientific journal Addiction found that vaping does not encourage more young people to start smoking.
Many studies have found that young people who try vaping are more likely to end up smoking. However, these studies tend to observe smoking rates in individuals who have vaped and those who have not, and such observational research cannot prove that the first factor causes the second. It can merely show that the two things correlate.
University College London professor Lion Shahab, senior author of the study, said, ““It could be the case that there’s a common vulnerability that explains this association. That could be, for instance, because there’s some genetic predisposition to try different things or there’s environmental pressures to try things.”
Shahab and his team used a time series analysis approach to assess the impact at the population level rather than the individual level to avoid this bias, the reasoning being that if there were a gateway effect then smoking rates should change in a related pattern as vaping rates change. And, if a gateway effect did not exist, changes in e-cigarette prevalence should not be associated with changes in uptake of smoking among young adults.
The team measured the gateway effect of vaping by looking at the association between prevalence of e-cigarette use among young adults and prevalence of uptake of smoking generally, including among people who have never smoked. They found no statistically significant association between the prevalence of e-cigarette se and every having smoked regularly among those aged 16 to 24. While vaping in this age group jumped to about 5% in 2013 and has hovered around there since, regular smoking rates fell from about 30% in 2013 to 25% in 2018, which was the last year of the study.
Dr. Emma Beard, lead author of the study, said, "These findings suggest that the large gateway effects reported in previous studies can be ruled out, particularly among those aged 18 to 24. However, we cannot rule out a smaller gateway effect and we did not study younger age groups. If the upper estimates are true, we would estimate that of the 74,000 e-cigarette users aged 16 to 17 in England, around 7,000 would become ever regular smokers as a consequence of e-cigarette use. At the same time, approximately 50,000 smokers are estimated to quit per year as a consequence of e-cigarette use".
Professor Shahab added, "These findings are important given the contrasting advice given by health bodies and governments in different countries. Research to date supports the argument that e-cigarettes are less harmful than tobacco and help smokers to stop smoking. Although some harm from vaping relative to never vaping cannot be ruled out, this study suggests there is little evidence of a substantial gateway effect into smoking."