Electronic cigarettes: hope from the hype may harm your health

It’s highly likely many vapers who continue to smoke do so because they’ve convinced themselves that cutting down on cigarettes has significantly reduced their risk. A. Currell/Flickr, CC BY-NC

A UK study published online in the journal Addiction has generated headlines proclaiming electronic cigarettes as an established new way to reduce the harms of smoking or quit altogether. But such claims are not only premature, they may be all smoke and mirrors.

Two of the biggest promises feeding the fervour for electronic cigarettes (e-cigs) are that they knock the socks off other ways of quitting smoking and that they’re a terrific way of reducing harm because “vaping” as it’s known, can reduce the number of cigarettes regular smokers consume.

But do electronic cigarettes actually help smokers quit?

Globally, there are probably hundreds of thousands of people who quit smoking by vaping. Many argue it’s their experience that counts, but the plural of anecdote isn’t evidence. Many people drive intoxicated every day without having car accidents, for instance, but that doesn’t count as evidence that driving under the influence of alcohol is safe.

Fuzzy numbers

Most studies on quitting cigarettes using e-cigs are almost worthless for smokers at large because they’re drawn from non-representative populations, such as vaping chatrooms.

Data from such research tend to show sometimes stratospheric success levels (this one, for instance, reported 81% quitting). But basing knowledge on the experiences of those for whom vaping is a major part of life is like polling active members of a wine appreciation society to understand community-wide drinking patterns.

And perish the thought that dedicated vaping advocates, including many with commercial interests, would ever stack a survey or tell pork pies to help their cause.

The Addiction study published last week is by far the most important study on how smokers use e-cigarettes.

This “real world” English study examined 5,863 smokers who’d made a quit attempt in the past year. It found 93 out of the 464 people who used e-cigarettes were successful (20%), while 194 out of the 1,922 people using nicotine replacement therapy made it (10.1%), and 535 out of 3,477 of the people trying to quit unassisted did so (15.4%).

Let’s look at these numbers another way. In this large study, 80% of smokers trying to quit by vaping were still smoking compared with 84.6% of those tried to quit on their own. That hardly looks like a champagne-popping difference deserving the accolades abounding in narratives about vaping.

And, of course, many of the quitters relapse weeks or months after completing the questionnaire, so the figures become less flattering over time. We know that, because of relapse, those quitting unassisted or with nicotine replacement therapy bought over the counter have about 4% continuous abstinence at 12 months.

We don’t have any data yet on relapses by e-cigarette users, but if we assume they do so at the same rate (cue vapers vehemently insisting that this is not true for vaping), then we might expect a tiny fraction over this 4%, regardless of method used, to be still not smoking a year later.

Misunderstood benefits

The most common outcomes of smokers vaping are that they smoke and vape at the same time (dual use rather than vaping instead of smoking) and they reduce the number of cigarettes smoked each day.

So isn’t this reduced smoking a major public health benefit for e-cigarettes?

Here, there’s a counter-intuitive paradox. There’s no disagreement about there being a dose-response relationship between the amount smoked and risk of disease. That is, the worst risk applies to people who start smoking early, smoke for a long time and smoke heavily.

So it sounds entirely reasonable to assume that people who cut down the number of cigarettes they smoke each day reverse that risk and reduce harm. But that’s far from what studies that follow large groups of smokers over many years have found.

A 30-year Norwegian study of 51,210 adults, for instance, found:

Long term follow-up provides no evidence that smokers who cut down their daily cigarette consumption by more than 50% reduce their risk of premature death significantly.

While a Danish study of 19,737 people with 15 years follow-up concluded “smoking reduction is not associated with a decrease in mortality from tobacco-caused diseases.” Two long-term Scottish studies concluded “reducing smoking consumption should not be promoted as a means of reducing mortality.”

And the largest of this type of research, a Korean study with 479,156 people followed for 11 years found:

No association between smoking reduction and all-cancer risk and that smoking reduction was associated with significant decrease in the risk of lung cancer, but size of risk reduction was disproportionately smaller than expected.

Finally, a systematic review of all smoking-reduction studies published before data from most of the above large studies were available, noted the studies were small and that a “substantial reduction seems to have a small effect” on mortality.

All studies reported that stopping smoking altogether had a significant impact on mortality.

Clearly, dual users who think they’re reducing their risk of death by smoking less are not basing their hopes on good evidence. And what we don’t know is how many smokers now using both would have quit altogether in the absence of electronic cigarettes. It’s highly likely many vapers who continue to smoke do so because they’ve convinced themselves that cutting down on cigarettes has significantly reduced their risk.

Meanwhile, headlines about the English study should probably have said there were nearly six times as many smokers who quit without any assistance than vapers who did.

The radical news that deserves shouting from the rooftops is that going cold turkey has always been the the method used by more successful quitters than any other method.