Teenagers who use e-cigarettes are up to five times more likely to start smoking tobacco cigarettes, compared to teens who do not use them, a new review by the Health Research Board (HRB) has found.

The HRB carried out the review to help inform the Department of Health's policy position in relation to e-cigarettes, particularly in relation to these devices as part of a tobacco harm reduction strategy.

E-cigarettes are battery-operated electronic devices that deliver nicotine and other products, including flavourings, to the user.

According to the Health Ireland survey of 2019, 12% of people in Ireland have tried e-cigarettes at some point, and 5% use them regularly. Some 10% of current smokers use the devices, along with 13% of ex-smokers.

Meanwhile a Health Behaviour In School survey found that more than 20% of 12-to-17 year-olds have used them at some point.

The review found that e-cigarettes are no more effective than approved and regulated nicotine replacement therapies (NRTs), which aim to help people stop smoking. However, e-cigarettes as a smoking cessation device are not regulated or approved and their safety beyond 12 months is not yet known.

The acute effects of e-cigarettes include poisonings, burns, lung injuries and asthma attacks and some of the chemicals in these devices are thought to cause cell and tissue damage.

"Some (chemicals) are agents that may cause cancer in the long term. The long-term health effects beyond 24 months are not researched," the review noted.

It said that the dual use of both e-cigarettes and conventional tobacco cigarettes is not less harmful than just smoking tobacco cigarettes alone, and this raises questions about the smoking reduction benefit of e-cigarettes.

Furthermore, teenagers who use e-cigarettes are three-to-five times more likely to start smoking tobacco cigarettes.

"Our findings highlight that e-cigarettes have the potential to negatively impact on the health of adolescents, leaving them more likely to initiate tobacco smoking. These factors would have to be considered as part of any smoking harm reduction strategy," commented Dr Jean Long, head of the HRB's Evidence Centre.

She added that more needs to be done to promote NRT and protect the health of teenagers and vulnerable groups "before considering the role of unregulated e-cigarettes as a harm-reduction approach".

The HRB review on e-cigarettes can be viewed here.