Young people who vape are three times as likely to start smoking, develop asthma and have poor mental health as those who do not, according to a study that lays bare the health impacts of e-cigarettes.
Vaping among young people is consistently linked to later smoking, according to the largest umbrella review of all the evidence on youth vaping, which warns that e-cigarettes could act as a gateway.
The researchers found associations with other harmful consequences including asthma, cough, injuries and mental ill health, as well as possible risks of respiratory disease, headaches, poor oral health and substance use.
Su Golder, an associate professor in health science at the University of York and an author of the research, said: “The consistency in the evidence is striking. Across multiple studies, young people who use e-cigarettes are more likely to smoke in the future. These findings support stronger public health measures to protect teens from the risks associated with vaping.”
The researchers concluded that although it was not yet possible to definitively say vaping leads children to smoke, precautionary policies to restrict sales and marketing of vapes to young people were needed.
Dr Ronny Cheung, of the Royal College of Paediatrics, said the study “adds to the mounting evidence that youth vaping is a serious threat to health and wellbeing, with strong links to smoking and other harmful behaviours”.
Cheung urged the government not to further delay implementing the tobacco and vapes bill, which will limit the flavours, packaging and marketing of vapes.
The World Health Organization (WHO) has previously described the rise in children vaping around the world as alarming. Figures compiled by Action on Smoking and Health this year showed that 20% of 11- to 17-year-olds in Great Britain had tried vaping, amounting to an estimated 1.1 million children, triple the levels in 2020.
For the new study, which was published in the journal Tobacco Control, researchers examined 56 reviews, most of which suggested that young people who vape are about three times as likely to start smoking as those who do not vape.
Asthma was the most common respiratory health condition, with consistent associations of between 20% and 36% increased risk of being diagnosed with the condition, and a 44% risk of worsening symptoms.
The researchers acknowledged that the umbrella reviews were of variable quality and that it was difficult to prove a causal relationship since the evidence was mostly observational. They urged further research to better understand whether vapes are genuinely acting as a gateway to smoking.
Last month, researchers at the University of Michigan established that a third of UK teenagers who vape will go on to start smoking tobacco, meaning they are as likely to smoke as their peers in the 1970s were.
Hazel Cheeseman, the chief executive of Action on Smoking and Health, said: “The rise in teen vaping in recent years is very concerning and needs urgent action from government. Vapes are effective quit aids for adults who smoke and while they are less harmful than smoking, they are not risk free and should not be used by children.”
Dr Stephen Burgess, a statistician at the University of Cambridge, said the research showed “that vaping users are more likely to engage in certain behaviours, but whether vaping is truly a cause of these behaviours is beyond the scope of the data”.
He added: “The associations demonstrated are both extensive in scope and strong in magnitude – it is clear that vaping users are at higher risk of many diseases than non-users. A causal explanation to the findings is both plausible and consistent with the evidence provided but such a finding can only be made conclusively by a randomised trial.
Ann McNeill, a professor of tobacco addiction at King’s College London, noted that many of the studies on which the researchers drew for the study were “rated critically low or low quality, meaning authors should be extremely cautious before making any conclusions”.
She said there could be other reasons for the consistency of the relationship between vaping and cigarette smoking – for example, a young person having a sensation-seeking or impulsive personality. Other research looking at population-level trends in vaping and smoking had found that as youth vaping increased in a population, smoking reduced, she said.
John Dunne, UK Vaping Industry Association director general, said: “We have seen a lot of research from the scientific community about vaping which does not stand up to scrutiny and this latest study seems to fit the bill.
“We need to stop demonising vaping because until the relative risks of cigarettes and vaping are understood by smokers then 220 people will needlessly die in the UK of smoking-related illnesses every day.”
A Department of Health and Social Care spokesperson said: “Our health advice is clear, while vapes are less harmful than smoking and can be an effective quit aid for smokers, children and non-smokers should never vape.
“The worrying rise in youth vaping requires attention – that’s why we commissioned this research, the largest comprehensive review of the health impacts of youth vaping to date.
“We are taking decisive action through the landmark tobacco and vapes bill and single-use vape ban, which will put an end to the cycle of addiction and stop the next generation getting hooked on nicotine.”