Tobacco still kills 6m people around the world every year. Despite huge public health efforts to help people quit and prevent young people starting, smoking remains the single greatest cause of ill health and premature death. And even with restrictions on tobacco advertising and smoking in public places, many young people continue to take up smoking. The situation is even worse in poorer countries, where support to stop smoking is limited, and tobacco control policies weaker.

So in light of this, how should we view the increasing popularity of electronic cigarettes? The gadgets deliver a nicotine hit by heating a nicotine-containing propylene glycol (e-liquid) to create an aerosol (usually called “vapour”), which is inhaled. Put simply, they deliver nicotine almost as effectively as a conventional cigarette, but without the vast majority of other chemicals present in tobacco smoke (either from the tobacco itself, or as a result of the burning process).

A whole culture is emerging around “vaping”. Many devices offer a range of power settings, and a vast array of e-liquids is on offer, with varying nicotine contents and flavours. Enthusiasts often apply modifications to their devices, and engage in “cloud chasing” – competing to produce the largest and most interesting clouds of vapour. And yes, young people are experimenting with e-cigarettes (in the same way that they have always experimented with pretty much everything), although at the moment there is no strong evidence this is leading to subsequent cigarette use, or even long-term e-cigarette use.

The rapid growth in use of e-cigarettes, especially among smokers trying to cut down or quit, has taken the public health community and the tobacco industry by surprise. Both are struggling to catch up. Health professionals are hurrying to carry out research to develop evidence-based guidelines and policies. Meanwhile, the tobacco industry is buying up e-cigarette companies and introducing its own products onto the market.

So how concerned should we be about this emerging and disruptive technology?

Should we encourage existing smokers to use e-cigarettes to help them stop smoking, even if this means they continue using nicotine long-term? In the United Kingdom there is some consensus that smokers should be encouraged to use e-cigarettes if they feel they might help, and the National Centre for Smoking Cessation and Training is supportive of their use. Part of the reason many vapers feel so passionately about the subject (and react strongly when they feel that vaping is being unfairly attacked) is that for the first time, through the use of e-cigarettes, they have felt able to take control of their nicotine habit, stop smoking, and reassert some control over their health, without being medicalised in the process.

Shutterstock

But a problem remains in the lack of information on the possible harm of e-cigarettes. This is unlikely to change any time soon, since the health effects of tobacco use can take several decades to emerge, and it’s probable the same will be true for e-cigarettes. Nothing is entirely risk-free, but the vastly reduced number of chemicals present in e-cigarette vapour compared to tobacco smoke means we can be confident that vaping will be much, much less harmful than smoking.

Heartening evidence

As part of the investigation into the effects of e-cigarettes, we investigated how the cells found in the arteries of the heart, known as human coronary artery endothelial cells, responded when they were exposed to both e-cigarette vapour and conventional cigarette smoke. We found the cells showed a clear stress response from the cigarette smoke, but not from the electronic cigarette. This suggests tobacco smokers may be able to reduce immediate tobacco-related harm by switching from conventional cigarettes to e-cigarettes.

Many people find it difficult to function without their first caffeine hit of the day. But no one is seriously calling for coffee shops to be dismantled or regulated. Nicotine is addictive, but much less so on its own than in tobacco, where other chemicals enhance its effect. At the doses consumed by vapers the harm is likely to be very low (although we need to continue to research this), and many vapers actually gradually move to zero nicotine content e-liquids, even while continuing to vape.

Of course, we may end up with a large population of long-term nicotine users who use e-cigarettes to deliver nicotine rather than cigarettes, but all of the evidence at the moment suggests that this population will almost entirely comprise ex-smokers. This would produce a vast public health gain.

We must be careful not to restrict smokers’ access to e-cigarettes, or over-state the potential harm of their use, if this will put people off making the transition from smoking to vaping. To do so would deny us one of the greatest public health improving opportunities of the last 50 years.