Vaping – touted as a tool to help smokers kick the butt – may in fact act as a gateway for young people to start smoking traditional tobacco cigarettes, a study warns.

E-cigarette use has risen rapidly among adolescents and young adults since the product was introduced to the US in 2007 and now exceeds the rate of cigarette smoking in this segment of the population.

E-cigarettes may harm public health and ultimately increase the burden of cancer if their use contributes to more cigarette smoking among youth. The study led by Samir Soneji and James Sargent from Dartmouth Institute for Health Policy and Clinical Practice in the US shows that this potential harm of e-cigarettes should be taken very seriously.

The study focused on whether e-cigarette use increases the risk of future cigarette smoking among adolescents and young adults.

The team conducted a systematic review and meta-analysis of published studies that began with nonsmoking youths and asked whether initial e-cigarettes use increased the risk they would subsequently transition to smoking cigarettes.

The results showed strong and consistent evidence of greater risk between initial e-cigarette use and subsequent cigarette smoking initiation, regardless of how initiation was defined and net other factors that predict cigarette smoking.

The studies did not address why e-cigarette use increases risk of transitioning to cigarettes, researchers said.

The reason could be that e-cigarettes mimic smoking behaviour through similar involvement of hand-to-mouth movements, or puffing and exhalation.

E-cigarette aerosol also contains nicotine, so use of these devices could enhance exposure and eventual addiction to this substance.

“The finding is very consistent across studies. That along with the strength of the association makes it probable that e-cigarette use is one cause of cigarette smoking,” said Sargent.

“E-cigarette use could affect population trends in youth smoking if use becomes more common, and that is the big public health concern,” he said.

The study appears in the journal JAMA Pediatrics.