A study published in the leading journal Addiction might just change everything for electronic cigarettes (e-cigarettes). The study of 1,473 English smokers found those who didn't use e-cigarettes were more likely to stop smoking after 12 months: 13.9 per cent of non-vapers successfully quit, compared with 9.5 per cent of occasional vapers and 8.1 per cent of daily e-cigarette users. The research is from a highly respected group of English researchers, one of whom has been all but venerated by activist vapers for his optimism over e-cigarettes. Curiously, the journal did not place the paper on its "early view" or "accepted articles" sections after passing through peer review, as is customary with nearly all papers these days. It was instead held from public view until today.
Past researchFor several years vaping advocates have promoted e-cigarettes as a tool to help smokers quit and greatly reduce harm, with one study making the ludicrous claim that e-cigarettes had a quit rate of 81%. The data here was obtained from self-selected participants in vaping advocates' chat rooms. It's unclear how many had a commercial interest in e-cigarettes. Eleven published studies have now investigated how people who vape compare with smokers who don't when it comes to quitting. Stanton Glantz from the University of California has meta-analysed these studies and found that smokers who vape are 30 per cent less likely to quit smoking than smokers who don't. Critics have pointed out that all these studies have lumped together daily users with less-than-daily users. This last group would include those who have tried vaping only occasionally or out of curiosity and so they'd be far less likely to be vaping in an attempt to quit smoking. But today's Addiction paper addresses this criticism by dividing participants into three groups: those who attempted to quit without the use of e-cigarettes; those who used e-cigarettes occasionally (less than daily); and those who used e-cigarettes daily.
Cutting backThere were three principal findings from the study. The first, predictably, was that far more smokers who used e-cigarettes daily were trying to quit smoking than those who used them less than daily. This is a bit like discovering that people who drink diet colas are trying to reduce their dietary calories. The second is that daily vapers reduced the number of cigarettes they smoke more than those who didn't vape every day:
Smokers using e-cigarettes daily when followed up were more likely [than less-than-daily vapers] to have achieved at least 50 per cent reduction in tobacco cigarette consumption from baseline.That may be so but the proportions making these substantial reductions were modest. Of those vaping every day, only 13.9 per cent reduced their smoking by at least half. So more than 86% of daily vapers are not making substantial reductions: they are vaping daily and often smoking as much as they always have. These long-term dual users are wonderful news for tobacco companies that are now selling cigarettes and e-cigarettes. After 12 months, nearly 6 per cent of smokers not using e-cigarettes at follow-up had also reduced their daily smoking by at least half. So the reduction attributable to e-cigarettes was only 8.2 per cent. Vaping advocates will chalk this finding up as a tick for harm-reduction, and argue that any cigarette foregone to an e-cigarettes is harm-reducing and therefore a good thing. This sounds reasonable until we look at the evidence from four cohort studies published since 2006 which reported on whether reducing smoking, as opposed to stopping smoking altogether, reduces the risk of early death. While there is strong evidence for a causal association between early uptake, amount smoked and duration of smoking, the evidence on "reverse engineering" harm by continuing to smoke while cutting back is far from strong. A Norwegian cohort of 51,210 people followed from the 1970s until 2003 found:
no evidence that smokers who cut down their daily cigarette consumption by more than 50 per cent reduce their risk of premature death significantly.A Scottish study of two cohorts followed from the 1970s to 2010 found no evidence of reduced risk of early death in those who cut their cigarette consumption, but clear evidence in quitters and concluded that:
reducing cigarette consumption should not be promoted as a means of reducing mortality.The largest study, from Korea, which followed 479,156 men for 11 years, found no association between smoking reduction and all cancer risk but a significant decrease in risk of lung cancer, with the size of risk reduction "disproportionately smaller than expected".