October 5, 2016

expert reaction to paper on the health effects of e-cigarettes

Publishing in The New England Journal of Medicine a group of researchers have examined the health effects of e-cigarettes.

All our previous output on this subject can be seen here. The SMC produced a Factsheet on e-cigarettes.

Prof. Peter Hajek, Director of the Tobacco Dependence Research Unit at Queen Mary University of London, said:

“There now exist a large number of studies which review the same e-cigarette literature. This particular review is peculiar in that its conclusions are at striking odds with its contents. The reviewed studies show that e-cigarette aerosol contains only a small fraction of harmful chemicals present in cigarette smoke, and even those are present in much lower quantities than in cigarettes. The conclusions, however, present the reduced risks of vaping as uncertain! The authors also assert, without presenting or reviewing any evidence in this area at all, that vaping may lure children to smoking. There is no good evidence for that whatsoever.

“It’s disappointing to see a non-systematic review come to such weak and, in my opinion, biased conclusions. Vaping is far less dangerous than smoking. I hope that this study doesn’t lead a single smoker to conclude otherwise.”

Dr Mike Knapton, Associate Medical Director at the British Heart Foundation, said:

“This review article is an assessment of the current evidence base on the biological effects of electronic cigarettes, their utility as a smoking cessation aid and the potential effects on our long term health.

“The conclusions are that while there are significant biological effects from using electronic cigarettes, it is impossible to reach a consensus on the safety of electronic cigarettes. This is in part due there being limited evidence available on the use and long-term heath effect of electronic cigarettes , and the unknown effects of the aerosol chemicals produced from the variety of different flavouring used in electronic cigarette liquids.

“However, electronic cigarettes are a much safer option to smoking tobacco, and as such provide relative safety when used as a short term smoking cessation aid or as a long-term alternative to smoking.

“Given the uncertainty about the long term safety of electronic cigarettes there are concerns that non-smokers are, or will start, using electronic cigarettes. This should be interpreted with caution, as the data on prevalence and patterns of use in the review are based on US populations and may not be observed in a UK population.

“More than one in six adults in the UK smoke, significantly increasing their risk of coronary heart disease. Stopping smoking is the single most important step you can take to improve your heart health, and we know that more and more people are turning to e-cigarettes to quit.

“Further research is needed to assess the potential long-term effects of these devices which is why the BHF is funding research to find out whether or not they are as safe as people think. In the meantime the most effective way to stop smoking is to use the NHS Stop Smoking Service or visit our website for helpful advice.”

‘The Health Effects of Electronic Cigarettes’ by Chitra Dinakar and George T. O’Connor published in The New England Journal of Medicine on Wednesday 5 October 2016.  

Declared interests

Prof. Hajek received researcher funding from and provided consultancy to manufacturers of stop-smoking medications. He has no links with any e-cigarette manufacturers. His research into e-cigarette safety and effects has been funded by NIHR, PHE, UKCTAS and MHRA.