Electronic cigarettes do appear to help people quit smoking, a major assessment of available evidence has revealed.

According to the findings, no serious side-effects are linked with their use for up to two years, however more studies are needed to assess potential long-term effects

Electronic cigarettes are battery-powered devices designed to supply nicotine through inhaled water vapour (vaping). Since their introduction, these products have been surrounded by controversy, with supporters stating that they can help people quit smoking, and others insisting that they normalise smoking and are potentially harmful to health.

The results come from the latest Cochrane Review, which are systematic reviews of health research that are carried out by international researchers. These reviews utilise the highest of standards.

The first Cochrane Review of e-cigarettes, which was published in late 2014, found that these cigarettes may aid smokers to stop smoking. This updated review concludes the same - e-cigarettes can help smokers to quit the habit.

The researchers noted that unlike other popular quitting tools, such as nicotine replacement patches and chewing gum, e-cigarettes mimic the experience of smoking because they are held in the hand and produce a smoke-like vapour when used.

As a result, they can help to produce similar sensations to smoking without having to expose users and those around them to actual cigarette smoke.

The 2014 review included two randomised controlled trials involving more than 600 people. This latest review includes observational data from an additional 11 studies.

Among the studies that looked at possible side-effects, no serious effects were noted for up to two years. In the short-to-medium term (up to two years), mouth and throat irritation were the most commonly reported side-effects.

"The randomised evidence on smoking cessation is unchanged since the last version of the review. We are encouraged to find many studies are now underway, particularly as electronic cigarettes are an evolving technology. Since the last version of the review, 11 new observational and uncontrolled studies have been published.

"In terms of quitting, these can't provide the same information we get from randomised controlled trials, but they contribute further information on the side-effects of using electronic cigarettes to quit smoking. None detected any serious side effects, but longer term data are needed," commented the review's lead author, Jamie Hartmann-Boyce, of the Cochrane Tobacco Addiction Group.

Details of these findings are published in the Cochrane Database of Systematic Reviews 2016.

Meanwhile, a new study published in the British Medical Journal has found that e-cigarettes may have helped as many as 18,000 people in England to quit smoking in 2015.

According to Prof Robert West of University College London, England is ‘sometimes singled out as being too positive in its attitude to e-cigarettes. These data suggest that our relatively liberal regulation of e-cigarettes is probably justified.'

Meanwhile, Alison Cox of Cancer Research UK commented that the evidence so far shows that e-cigarettes are ‘much safer than tobacco'.