Picture: File The research is the first UK evidence that vaping may act as a gateway to smoking.

TEENAGERS who use electronic cigarettes are four times more likely to move on to tobacco, a study found.

The research is the first UK evidence that vaping may act as a gateway to smoking.

E-cigarettes contain liquid nicotine that is heated into vapour, avoiding the harm caused by tobacco smoke.

Around three million British adults have used e-cigarettes in the decade or so they have been on the market.

Health experts agree the devices are much safer than smoking tobacco. They are thought to help 22,000 people quit smoking each year, and there are plans to make them available on NHS prescriptions.

But some say there are unresolved safety concerns.

US studies have warned teenagers who use the gadgets are more likely to ‘graduate’ to tobacco later.

British doctors have insisted there is no evidence that this is the case in the UK. But the latest study, in the BMJ journal Tobacco Control, suggests for the first time that the ‘robust association’ between vaping and smoking exists here as well.

Experts led by Leeds University staff examined survey responses from 2,836 pupils at 20 schools in England, aged 13-14, and a year later, at 14-15. Among those who had never smoked but had tried an e-cigarette, 34 per cent tried smoking tobacco over the year. Among those who had not smoked and never used an e-cigarette, only 9 per cent tried tobacco.

The scientists pointed out they asked only whether pupils experimented with tobacco – meaning some may have tried it only once.

Study leader Professor Mark Conner of Leeds University said that among teenagers who had never smoked, ‘use of e-cigarettes was a strong predictor that within 12 months they would have tried a conventional cigarette’.

But Professor Linda Bauld of Stirling University said: ‘This study does not provide evidence that using e-cigarettes causes young people to become smokers?…?smoking among young people in the UK is at an all-time low.’

It is illegal in the UK to sell e-cigarettes to under-18s.

© Daily Mail