January 24, 2018

expert reaction to meta-analysis of the dangers of one cigarette a day

Scientists publish a systematic review and meta analysis in the BMJ which examines the association between low cigarette consumption and risk of coronary heart disease and stroke.

Prof. Peter Hajek, Director of the Tobacco Dependence Research Unit, Queen Mary University of London (QMUL), said:

“Stopping smoking completely is a good advice, but the accompanying editorial and the final point in the press release are grossly misleading.

“The study results have no relationship to the claim that ‘the message for regulators dealing with newly marketed ‘reduced risk’ products is that any suggestion of seriously reduced coronary heart disease and stroke from using these products is premature.’ The study concerned cigarettes rather than nicotine replacement treatment products or e-cigarettes, and there is extensive evidence that these products pose at worst only a small fraction of cardiovascular risks of smoking.

“The misinformed editorial is based on extreme and discredited anti-vaping claims: that the presence rather than the content of particles affect health; that acute effects of nicotine with no link to health outcomes are a sign of danger; that the fact that the same teenagers try vaping and smoking means that vaping leads to smoking, despite clear evidence of an accelerated decline in youth smoking; that vaping increases smoking despite extensive evidence to the contrary, etc.  It makes recommendations that – if acted upon – would keep smokers smoking and be damaging to public health. This bit of anti-vaping propaganda should not have passed editorial control at BMJ!”

Prof. Paul Aveyard, Professor of Behavioural Medicine at the University of Oxford, said:

“This well-conducted study confirms what many epidemiologists have suspected but few among the public have: light smoking creates a substantial risk for heart disease and stroke.  The implication is obvious- anyone who smokes should stop.

“However, it would be wrong to conclude from this study that cutting down smoking is useless.  There is more reason to believe that lower cigarette consumption will reduce the risk of chronic lung disease and lung cancer, the other two big causes of early death from smoking, but whether this occurs or not is less clear and the study team did not look at this.

“The main reason we should continue to support people to cut down their smoking is that many want to do it and try to do so.  Those who try to cut down with the aid of nicotine, whether from nicotine replacement treatment or an e-cigarette, are more likely to stop eventually and thus really reduce their risks from smoking.  Some people who do reduce and then stop smoking continue to use nicotine replacement or e-cigarettes.  That they do so matters much less than the fact that they have stopped smoking completely.”

* ‘Low cigarette consumption and risk of coronary heart disease and stroke: meta-analysis of 141 cohort studies in 55 study reports’ by Allan Hackshaw et al.  published in The BMJ on Wednesday 24 January 2018.

Declared interests

Prof. Peter Hajek: No conflicts.

Prof. Paul Aveyard: I have led a trial in which GSK donated free nicotine patches.