Leading journal questions Public Health England’s stance on e-cigarettesBMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h4684 (Published 02 September 2015) Cite this as: BMJ 2015;351:h4684
All rapid responses
O’Dowd’s news on Public Health England’s (PHE) review which claimed “e-cigarettes were 95% less harmful than normal cigarettes” and on the wise warning from the Lancet could have been more stimulating.(1,2,3).
Not only is the review not evidence based but it also failed to model. The widespread promotion of e-cigarettes may have a wide range of seriously deleterious population-level health effects such as the renormalisation of cigarette smoking, the diversion of current cigarette smokers and healthcare providers from effective evidenced based treatments, the offer of a new gateway to addiction for the youngest.(4) Moreover, PHE confused health information to lay people with marketing slogans.
Could this may be worse than confusion? PHE is a governmental agency and taxes for cigarettes in the UK, 86%, are a major issue for the government. The tobacco industry argues it contributes £12.3bn/y to the exchequer and Imperial is one of the largest tax contributors in the FTSE 100! This does not take into account the cost savings in pension payments due to smokers’ premature death, roughly ten years. Coincidentally, tobacco control seems out of breath: 19 per cent of those aged 16 and over were smokers in 2013, a rate that has remained largely unchanged in recent years.(http://www.hscic.gov.uk/catalogue/PUB17526)
PHE began operating on 1 April 2013. After being tackled by Pr McKee (http://www.theguardian.com/uk-news/2014/jan/08/top-10-causes-death-londo...) it is now tackled by the Lancet. As things come in threes, what’s next?
1 O'Dowd A. Leading journal questions Public Health England's stance on e-cigarettes. BMJ 201;351:h4684
2 McNeill A, Brose LS, Calder R, et al. E-cigarettes: an evidence update—a report commissioned by Public Health England. 19 Aug 2015. www.gov.uk/government/ publications/e-cigarettes-an-evidence-update.
3 Lancet. E-cigarettes: Public Health England’s evidence based confusion. Lancet 2015:386;829.
4 Kalkhoran S, Glantz SA. Modeling the health effects of expanding e-cigarette sales in the United States and United Kingdom: A Monte Carlo analysis. JAMA Intern Med. 2015. Online Aug 31. doi: 10.1001/jamainternmed.2015.4209.
Competing interests: No competing interests
The recent Public Health England evidence update on e-cigarettes that has recently been commented in the BMJ  is an important review by experts that will certainly guide public health policy in the UK. However, although the use of e-cigarettes is currently perceived to be less harmful, they are not without risk. Albeit, in lower concentrations than in cigarette smoke, these solutions contain carcinogens including formaldehyde and acetaldehyde, which are present in significantly greater concentrations when high-voltage devices are used.  In addition to the risk of oral and lung cancer from inhalation of these compounds, in pre-clinical experimental models e-cigarette vapour is associated with increased inflammation, oxidative stress and disruption of endothelial barrier function.  Furthermore, these effects on the airway may promote allergen-induced airway hyper-reactivity, and predispose to respiratory virus  and bacterial infection  by impairing immune function and enhancing the virulence of pathogens such as methicillin-resistant Staphylococcus aureus. 
Further basic science and epidemiological research is required to increase our evidence base of the benefits and harms of e-cigarette vapour but at present patients should not be misled that the likelihood of future harm is negligible when there is insufficient evidence to advocate this.
1 O’Dowd A. Leading journal questions Public Health England’s stance on e-cigarettes. BMJ 2015;351:h4684.
2 Kosmider L, Sobczak A, Fik M, et al. Carbonyl compounds in electronic cigarette vapors: effects of nicotine solvent and battery output voltage. Nicotine Tob Res 2014;16:1319–26. doi:10.1093/ntr/ntu078
3 Schweitzer KS, Chen SX, Law S, et al. Endothelial disruptive proinflammatory effects of nicotine and e-cigarette vapor exposures. Am J Physiol Lung Cell Mol Physiol 2015;309:L175–87. doi:10.1152/ajplung.00411.2014
4 Lim H Bin, Kim SH. Inhallation of e-Cigarette Cartridge Solution Aggravates Allergen-induced Airway Inflammation and Hyper-responsiveness in Mice. Toxicol Res 2014;30:13–8. doi:10.5487/TR.2014.30.1.013
5 Wu Q, Jiang D, Minor M, et al. Electronic cigarette liquid increases inflammation and virus infection in primary human airway epithelial cells. PLoS One 2014;9:e108342. doi:10.1371/journal.pone.0108342
6 Sussan TE, Gajghate S, Thimmulappa RK, et al. Exposure to electronic cigarettes impairs pulmonary anti-bacterial and anti-viral defenses in a mouse model. PLoS One 2015;10:e0116861. doi:10.1371/journal.pone.0116861
7 Crotty Alexander L, Enany S, Hwang H, et al. Electronic Cigarette Vapor (ECV) Exposure Decreases Staphylococcus Aureus Susceptibility To Macrophage And Neutrophil Killing (ATS Journals). In: American Thoracic Society International Conference Meetings Abstracts. 2014.
Competing interests: No competing interests
Jensen BS et al  postulated that formaldehyde releasing agents may deposit more efficiently in the respiratory tract than gaseous formaldehyde so that they could carry the high slope factor for cancer. These findings cannot be ignored: however, the report by Public health England (PHE) claims e-cigarettes can be a helpful tool in quitting smoking but in order to reach any such conclusion it requires proper evidence.
Moreover, I wonder that so much has been discussed regarding e-cigarette but the potential risks of e-cigarettes in the oral cavity have completely been ignored. The components of e-cigarette comprise an aerosol generator, a flow sensor, a battery and a nicotine containing solution storage area.  Nicotine is considered an etiological factor of periodontal diseases and formaldehyde is a well known carcinogen. Little is known about the types or concentrations of chemicals, including nicotine, in e-cigarettes. The chemicals and addictiveness may vary based on the brand. It can be concluded that e-cigarettes can be safer only for short term usage; the potential harmful effects as well as its usefulness need more evidence.
1. Jensen RP, Luo W, Pankow JF, Strongin RM, Peyton DH. Hidden formaldehyde in e-cigarette aerosols. N Engl J Med 2015;372:392-39
2. Callahan-Lyon P. Electronic cigarettes: Human health effects. Tob Control 2014; 23:ii36-40.
Competing interests: No competing interests
E-cigarettes: setting out the available evidence for the public
Public Health England (PHE) is deeply disappointed with the BMJ’s news story: “Leading journal questions Public Health England’s stance on e-cigarettes”. The Lancet editorial, to which this news story refers, contained a number of assertions that PHE has refuted in a published response. 
The authors of PHE’s expert review on e-cigarettes  have set out the evidence for the estimate that e-cigarettes are around 95% safer than smoking.  This evidence includes the facts that: 1) the constituents of cigarette smoke that harm health – including carcinogens – are either absent in e-cigarette vapour or, if present, they are mostly at levels much below 5% of smoking doses; and 2) the main chemicals present in e-cigarettes only have not been associated with any serious risk.
The Lancet, and the BMJ news story both focus their criticisms on the study by Nutt et al. which is cited in PHE’s review. We disagree strongly with the charge that PHE’s review does not meet our standard for scientific rigour and evidence. We would add that the study by Nutt et al. was one source within an extensive peer-reviewed evidence base, on which the authors drew in reaching their conclusions on the relative safety of e-cigarettes.
PHE’s expert review clearly acknowledges that the overall evidence base on the safety of e-cigarettes is still developing. Furthermore, we have repeatedly stressed that ongoing monitoring and research are needed. But PHE has a public duty to spell out clearly that the current best estimate, based on the peer-reviewed literature, is that e-cigarettes, while not risk-free, carry only a fraction of the harm caused by smoking.
It is even more disappointing that the BMJ has followed the Lancet in ignoring the significant findings of this comprehensive expert review. These include: 1) e-cigarettes are now the most popular stop smoking aid in England and can help smokers to quit smoking or reduce their cigarette consumption; 2) while experimentation with e-cigarettes has increased among young people, regular use remains rare and almost entirely confined to those who have already smoked; and 3) there is so far no evidence that e-cigarettes are undermining the long-term decline in smoking among adults and young people.
PHE has not “fallen short of its mission” in publishing the latest evidence on e-cigarettes. The public increasingly – and mistakenly – believes that e-cigarettes are at least as harmful as smoking tobacco. This may be keeping smokers from using e-cigarettes as a tool to help them to quit smoking and compromising the potential for these products to help reduce the harm from the nation’s number one killer.
 E-cigarettes: spelling out the available evidence for the public. O’Connor R and Fenton K. The Lancet. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(15)00107-5/abstract
McNeill, A, Brose, LS, Calder, R, Hitchman, SC, Hajek, P, and McRobbie, H. E-cigarettes: an evidence update. Public Health England. https://www.gov.uk/government/publications/e-cigarettes-an-evidence-update; August 2015
 McNeill, A and Hajek, P. Underpinning evidence for the estimate that e-cigarette use is around 95% safer than smoking: authors' note. Public Health England. https://www.gov.uk/government/uploads/system/uploads/attachment_data/fil... August 2015
Competing interests: Public Health England commissioned the review on e-cigarettes that is the subject of the BMJ news story
The anonymous Lancet editorial (1) now re-reported here (2) criticises our Public Health England commissioned evidence update (3). We published a letter (4) in response to the Lancet editorial which was ignored by the BMJ and so we reiterate and expand on the key messages here.
The criticism was based on perceived flaws in one of the 185 references we used, ignoring the rest of our 111 page document which addresses population effects of e-cigarette use, regulations, attitudes as well as concerns over safety. Both commentaries focused on the estimate of risk reduction and protested strongly against the media reassuring smokers that switching to e-cigarettes provides substantial health benefits, but have provided no data to counter the estimate, nor any reason as to why the message smokers can benefit from switching to vaping is an undesirable one.
Further details on the relative risks are given elsewhere (5,6) . In brief, the estimate that e-cigarette use is around 95% less harmful than smoking is based on the facts that 1) cigarette smoke constituents that harm health are either absent in e-cigarette vapour or, if present, are mostly at levels much below 5% of smoking doses, and 2) the main chemicals present in e-cigarettes only have not been associated with any serious risk. Some constituents and flavourings in e-cigarettes may yet turn out to pose risks over long term; the 5% residual risk is a cautious estimate allowing for this uncertainty. Our review highlighted how smokers are currently misinformed about these relative risks.
One of the aims of our review was to assess whether studies that have recently been widely reported as raising new alarming concerns on the risks of e-cigarettes changed the conclusions of the previous independent review (7). We concluded that these new studies do not in fact demonstrate significant new risks. Our review also documented that e-cigarettes are not undermining the long-term decline in cigarette smoking among adults and youth and are attracting very few people who have never smoked into regular vaping. As we stated in our report, ongoing monitoring is needed to ensure that if any new risks emerge, recommendations to smokers and regulatory requirements are revised accordingly.
Current evidence indicates that smokers who switch from smoking to vaping reduce the risks to their health dramatically. We believe this needs to be communicated and that undermining this message will keep smokers smoking and dying as a result.
McNeill A, Brose LS, Calder R, Hitchman SC
Institute of Psychiatry, Psychology & Neuroscience, King’s College London
Hajek P, McRobbie H
Queen Mary, University of London
(1) E-cigarettes: Public Health England’s evidence-based confusion. Lancet, 385, August 29 2015
(2) News: Leading journal questions Public Health England’s stance on e-cigarettes. BMJ 2015;351:h4684
(3) McNeill A, Brose LS, Calder R, Hitchman SC, Hajek P, McRobbie H. E-cigarettes: an evidence update – A report commissioned by Public Health England, Public Health England, August 2015
(4) McNeill A, Brose LS, Calder R, Hitchman SC, Hajek P, McRobbie H. E-cigarettes: the need for clear communication on relative risks. DOI: http://dx.doi.org/10.1016/S0140-6736(15)00079-3
(5) See https://www.gov.uk/government/uploads/system/uploads/attachment_data/fil...
(6) See http://drugscience.org.uk/blog/2015/08/27/blinded-smoke-why-do-e-cigaret...
(7) Britton J, Bogdanovica I. 2014. Electronic cigarettes A report commissioned by Public Health England, 2014.
Competing interests: HM was an investigator on a 2008 study of e-cigarettes sponsored by manufacturer Ruyan Group and conducted independently at University of Auckland. He has no links with any tobacco or e-cigarette manufacturers. The other authors declare no competing interests.