A third of UK teenagers who vape will go on to start smoking tobacco, research shows, meaning they are as likely to smoke as their peers were in the 1970s.
A long-term intergenerational study found that the likelihood of starting to smoke among people aged 17 in 2018 was about 1.5% if they did not vape compared with 33% if they did.
The findings suggest that e-cigarettes are increasingly acting as a “gateway” to nicotine cigarettes for children, undermining falling rates of teen smoking over the past 50 years.
The study looked at teenagers in 2018 as it was the most recent year for which there was available comparable data. The likelihood may have increased since then given that vaping and smoking rates among teenagers have both risen in the past seven years.
The academics wrote that although the research did not establish a causal link, their findings were “especially concerning” given the rising popularity of vaping, “despite some initial assurances that e-cigarettes would have little appeal to [adolescents]”.
“The success of previous tobacco control efforts and broad shifts in intergenerational risk factors in reducing risk of cigarette smoking may be mitigated when adolescents use e-cigarettes,” they wrote.
Figures compiled by Action on Smoking and Health this year show that 20% of 11- to 17-year-olds in Great Britain have tried vaping, an estimated 1.1 million children. This was the same level as in 2023, after the number of children using vapes in the previous three years had tripled. Smoking among youths also increased from 14% in 2023 to 21% in 2025.
The research, led by the University of Michigan and published in the Tobacco Control journal, drew on intergenerational data from three nationally representative birth cohorts of UK teens born in 1958, 1970 and 2001.
The overall likelihood of cigarette smoking for an average teen (aged 16 or 17) was calculated as 30% for those born in 1958, 22% for those born in 1970, and 9.5% for those born in 2001.
The odds of smoking among 16- and 17-year-olds were estimated based on a common set of childhood risk factors, which included teen vaping for the youngest cohort. Some sociodemographic characteristics, including race and ethnicity, were unaccounted for due to insufficient sample sizes in the earlier cohorts.
Risk factors included whether they had ever drunk alcohol by age 16 or 17; how engaged they were with education at school; poor impulse control reported by the main caregiver at ages 10 or 11; and parental occupation, education and smoking behaviour – including during pregnancy. The researchers found these risks remained broadly similar across the three cohorts.
Analysis showed a steep decline in the prevalence of cigarette smoking among teens, falling from 33% in 1974 to 25% in 1986 and 12% in 2018.
The researchers suggested the decline in the prevalence of teen smoking was the result of tobacco control laws, better public understanding of the health impacts of smoking and a shift away from the perception of smoking as socially acceptable.
The study showed that other behaviours that contributed to the risk of smoking have changed over time.
For example, the percentage of teens who had started drinking by the age of 16 or 17 fell from 94% for the oldest cohort to 83% in the youngest.
The average age at which mothers left education rose from 15.5 in the oldest cohort to 17 in the youngest, the prevalence of parental smoking fell from above 70% in the oldest to 27% in the youngest cohort, and fewer mothers continued smoking while pregnant.
Steve Turner, president of the Royal College of Paediatrics and Child Health, said the research was “incredibly concerning”.
“A major concern about children and young people vaping is that this age group is particularly sensitive to developing a lifelong addiction to the nicotine contained in the vapes. We know that nicotine addiction is harmful,” he said.
“We have all worked so hard to stop young people from smoking and vaping may have undone decades of work.
“Smoking continues to be the leading cause of preventable illness and death in the UK. We all must take urgent steps to prevent young people from being drawn into smoking by vaping.”