E-cigarettes are a potential smoking cessation aid and they may also be able to lower the risk of nicotine dependency in high-risk groups. The available scientific evidence, however, remains insufficient. This is the conclusion reached by Dennis Nowak et al. from Munich in this issue of Deutsches Arzteblatt International.
The authors performed a systematic literature search for data on e-cigarettes' mechanism of action, their emissions, how they are seen by groups of potential users, their efficacy in smoking cessation, and their addiction potential. According to an international survey e-cigarettes were used by younger people, those with higher incomes, and heavier smokers in particular. Among e-cigarette users, 85% reported that they used them to stop smoking. According to repeat surveys in the U.K., the number of people who were aware of e-cigarettes doubled between 2010 and 2012, and the number of users increased four-fold. An online survey of e-cigarette users found that 74% of those asked had not smoked tobacco for at least several weeks since using e-cigarettes, and 70% reported reduced cigarette cravings. However, there is evidence that people who have never previously smoked also use e-cigarettes. The rates among Polish and US students, for example, were 3% and 9% respectively.
Only two controlled trials show e-cigarettes as having similar effects to nicotine replacement therapies as smoking cessation aids; these effects were almost independent of nicotine content. The authors call for more randomized trials to be conducted.