E-cigarettes are used by millions in the UK, but information about them is sometimes conflicting. So what is the current evidence on them?

It has been described as a ‘disruptive technology’ potentially capable of breaking our fatal relationship with tobacco. So the setting for a public debate on e-cigarettes - a museum part-funded by the tobacco industry, in a city home to the global headquarters of one of the largest tobacco manufacturers - was perhaps ironic. Yet on Wednesday evening, I found myself at the M-Shed in Bristol, watching just that: a debate about whether e-cigarettes could be part of the solution to the tobacco epidemic.

To mark the launch of a new Integrative Cancer Epidemiology Programme, linked to the Medical Research Centre Integrative Epidemiology Unit at the University of Bristol, Professor Marcus Munafò (Professor of Biological Psychology at the University of Bristol) and Professor Linda Bauld (Professor of Health Policy at the University of Stirling), both collaborators of mine, discussed e-cigarettes. Professor Gabriel Scally (Public Health Doctor and former Regional Director of Public Health for the South West of England) chaired the discussion.

Billed as a debate about whether e-cigarettes might be ‘the key to reducing smoking’, some in the audience may have expected a heated discussion. However, with this line-up of academics, influential in the fields of public health, tobacco and addiction, the discussion was evidence-based and measured. As for the motion of the debate, the panel was unanimous: e-cigarettes may not be the key to reducing smoking, but they are certainly an important part of the solution.

This may be surprising to some, given ongoing discussions surrounding e-cigarettes in the media. So what is the current evidence on e-cigarettes?

Although we don’t know the long-term health effects of e-cigarette use, they’re less harmful than cigarettes

Pretty much everything is safer than cigarettes. There is no other consumer product, which, when used as the manufacturer intends, kills every other user, taking from them an average of 10 years of healthy life.

It’s been said that “people smoke for the nicotine, but die from the tar”. E-cigarettes present a solution to this problem by providing a ‘clean’ (or cleaner) method of nicotine delivery. They deliver nicotine in a similar way to a cigarette (and much faster than other forms of nicotine replacement therapy; NRT), but don’t contain the other chemicals that ultimately kill cigarette users.

A recent Public Health England report stated that e-cigarettes are 95% less harmful than cigarettes, a controversial figure. However, as Linda pointed out, it’s almost irrelevant whether e-cigarettes are 95%, 90% or even 80% less harmful than cigarettes. What’s important, is that they are less harmful.

There's no evidence e-cigarettes are as harmful as smoking Read more

Yes, there are still some concerns about e-cigarettes and increasing levels of confusion and misinformation among the public around them. Evidence suggests that both adults and teenagers are more likely to report that e-cigarettes are equally harmful as cigarettes today, than they were a few years ago. Both Marcus and Linda speculate that these views may have been shaped by media reports fueled by disagreements between academics.

Horror stories of children drinking the liquid nicotine (a problem which can be alleviated by having stricter controls on safety caps) and fires and accidents caused by exploding devices (the frequency of which is still far lower than the risk of fire posed by cigarettes) have been reported in the media. There are ongoing concerns about the chemicals produced when e-cigarettes are used, some of which are the same as the dangerous chemicals found in burning cigarettes (although the amount of these chemicals is a tiny fraction of the amounts found in cigarettes). Finally, we can’t yet be certain about the long-term health consequences of vaping, simply because people haven’t been using them for long enough to know (just like we didn’t know for decades that cigarettes definitely caused lung cancer).

For these reasons, we should be careful to ensure that children and non-smokers don’t start using e-cigarettes - currently there is very little evidence that these groups are regularly using the devices. However, most academics and public health officials are in agreement that for current smokers, e-cigarettes are a safer alternative to smoking.

E-cigarettes can be an effective method of stopping smoking

Linda presented evidence on the effectiveness of e-cigarettes for smoking cessation. E-cigarettes seem to be somewhere in the middle of the range when it comes to helping smokers quit. Some studies show that they are more effective than either willpower alone or NRT bought over the counter, but less effective than behavioural support.

The type of e-cigarette used matters too. The early models (‘1st generation’ or ‘cigalike’ models) don’t seem to be very effective methods of smoking cessation – interestingly, these are predominantly the models being bought up by the tobacco industry. The 2nd generation e-cigarettes and tank models (which can be refilled with liquids) seem to lead to higher levels of quitting success.

The sheer reach of e-cigarettes is their most powerful weapon. While behavioural support for cessation, combined with NRT or varenicline, has been underused by smokers wanting to quit, the rise of e-cigarette use over the past five years has been unprecedented. There are now an estimated 2.6 million vapers in the UK. With such a large numbers of users, even modest levels of smoking cessation success from their use will have a large impact on cessation rates.

E-cigarettes are a consumer-led revolution

The speed of the e-cigarette revolution and its ability to galvanize a whole community of individuals who now define themselves as ‘vapers’ is impressive. Never before has a route out of smoking garnered as much support from its users. As far as I know, there are no online forums for nicotine patch users to discuss optimal patch placement, no celebrity endorsements for nicotine lozenges and no users of nicotine nasal sprays challenging European Union Directives.

Many vapers feel passionately that e-cigarettes have enabled them to quit smoking. Indeed, a passionate crowd was in attendance at the debate. When asked at the beginning to raise their hands if they had ever tried an e-cigarette, over half of the audience did so. This is in comparison to population surveys that report 1.5%, 16.5% and 58.5% rates of ever use among non-smokers, ex-smokers and daily smokers respectively.

The last question in the debate came from a member of the public who defined himself as a ‘vaper and ex-smoker’. He expressed his dismay that new the EU Tobacco Products Directive (TPD - due to come into force in May 2016) will impose strict regulations on e-cigarettes, including bottle sizes, tank sizes and nicotine strength. In order to continue selling e-cigarettes not meeting these new regulations, retailers can instead apply for their products to be registered as medicines. But this is an extremely costly route, likely to be impractical for the majority of e-cigarette retailers other than the incredibly wealthy tobacco industry. The TPD is currently being challenged by one e-cigarette retailer. However, if it goes ahead, there are concerns from vapers and those in the public health community, that it may mean the end of vaping as we know it.

Arguably one of the reasons why e-cigarettes are so popular is that they reflect a consumer-led revolution, built from the ground up. Users can personalise their product, and many see vaping as a lifestyle choice rather than a smoking cessation aid or a medicine. If strict regulation means fewer smokers switch to using e-cigarettes, this could be a huge public health opportunity missed.

Olivia Maynard is a tobacco researcher at the University of Bristol. You can find her on twitter @oliviamaynard17.