Blood Vessel Study Trashed

Posted 14th November 2019 by Dave Cross
Every year prior to the E-Cigarette Summit meeting at The Royal Society in London the media is flooded with second-rate studies and scare stories about vaping. This week we’ve seen a boy claim vaping almost killed him, and today German cardiologists claim vaping damages the brain, heart, blood vessels and lungs.

The researchers say in the paper that “aggressive steps are warranted to limit” the use of electronic cigarettes. "We cannot allow an entire generation to become addicted to nicotine," said lead author Münzel, so he set about aggressively harming loads of mice.

Calls to clamp down on vaping as a result were knocked by Kings College London’s  Dr Garrett McGovern: “Banning e-cigs would be catastrophic and needs to resisted at all costs.”

The study sparked a large response from experts. Professor Peter Hajek, Director of the Tobacco Dependence Research Unit, Queen Mary University of London, reacted: “The authors detected two effects. In human smokers, nicotine from e-cigarettes produced a typical acute stimulant effect, also seen after drinking coffee, that on its own signals no danger.  In mice and in tissue samples, acrolein, a chemical that can be generated when e-liquid is fried, had more damaging effects. This however is not relevant for human vapers. Frying e-liquid produces this chemical, but this also produces aversive taste that vapers avoid. Human vapers have acrolein levels that are similar to non-smokers and much lower than in smokers.”

Professor Ajay Shah, Head of School of Cardiovascular Medicine & Sciences, and the British Heart Foundation Professor of Cardiology at King’s College London, said: “The second part of the study was to expose mice to e-cigarette vapour for up to five days and assess the impact on vessels, the lungs and the brain. The researchers found evidence of some damage to all these organs but these results are less straightforward to extrapolate to humans, and the researchers did not include all the appropriate control groups to improve confidence in this result. The conclusions from the animal studies regarding possible effects on the lungs and brain therefore require further research in people to assess if the same happens in humans.

“People would only be endangered when switching from cigarettes to e-cigarettes if the e-cigarettes were known to be MORE of a danger to health, and there is no evidence to suggest this is true” - Dr Gavin Sandercock

University of Essex’ Dr Gavin Sandercock, Reader in Clinical Physiology (Cardiology) and Director of Research, commented: “This study was done in mice and in 20 human smokers.  The mouse work is very complex but I didn’t find it very compelling. The human work is complicated by the fact the people were current smokers so we can’t tell how much of the observed effect could be down to smoking-related damage. All the effects vaping had on the human smokers were short-term changes we know happen when nicotine enters the body; by smoking cigarettes, vaping, using patches or gum’ – they are not specific to vaping.  Many of the potential health problem suggested in the study are not based on the humans who took part, but come from experiments done in mice.  This makes the findings difficult to generalize to human health.”

“The authors say that ‘in the UK, 1.6% of those aged 11-18 use e-cigarettes more than once a week, compared with 0.5% in 2015’ – but these numbers are meaningless without knowing how many of the 1.6% were already smokers, or how many would have smoked cigarettes anyway even if they didn’t vape. Vaping may be less healthy than breathing air but all the evidence so far suggests it is nowhere near as unhealthy as smoking cigarettes. Because cigarettes are so harmful, much more harmful than vaping, any child who vapes instead of smoking is better off. Likewise any smoker who switches to e-cigarettes is likely to improve their health compared with someone who continues to smoke cigarettes.”

“The authors describe how they measure blood flow and arterial stiffness in 20 current smokers before and after vaping an e-cigarette.  But we know cigarette smoking causes endothelial dysfunction – that is a fact.  The changes described here following vaping are short-term, small, not necessarily indicative of poor health by themselves, and might have been very different in non-smokers or even in habitual vapers compared with this small sample of smokers.  So, we can’t tell how much of these effects were down to the fact these people were smokers.”

“The authors say ‘Our data may indicate that e-cigarettes are not a healthy alternative to traditional cigarettes, and their perceived ‘safety’ is not warranted’ – but this argument fails to address the ‘relative’ safety of vaping over smoking cigarettes.  Cigarettes increase the risk of early death by at about one third, and there is as yet no actual evidence that e-cigarettes are a threat to health.  There is certainly no evidence that they are worse than or as bad as cigarettes.”

He continues: “The authors say ‘The e-cigarette epidemic in the US and Europe, in particular among our youth, is causing a huge generation of nicotine-addicted people’ – I do not agree with this statement. According to the CDC last year, smoking rates fell to a record low of 14% in the US, and the graphs from the WHO1 show how much smoking has declined in the Germany (where this study took place) and across Europe. The WHO also project further declines in smoking prevalence – which does not support any suggestion that there is a rise in nicotine addiction.”

“People would only be endangered when switching from cigarettes to e-cigarettes if the e-cigarettes were known to be MORE of a danger to health, and there is no evidence to suggest this is true.”

Professor Jacob George, University of Dundee, said: “With regards to the human study, it is impossible to draw any firm conclusions from these small, single exposure studies which is why larger randomised clinical trials are needed. The results are also at odds with larger and longer duration clinical trials by D’Ruiz et al. and Farsalinos et al. that demonstrate reduction in blood pressure with e-cigarette use, which implies improvements in vascular function with e-cigarette use. Because this study couldn’t tease out the effects of prior tobacco cigarette use and dual-use (most vapers are ex-smokers) on these volunteers, the conclusions are far from clear.”

Related:

  • "Short-term e-cigarette vapour exposure causes vascular oxidative stress and dysfunction: evidence for a close connection to brain damage and a key role of the phagocytic NADPH oxidase (NOX-2)" by Münzel et al. – [link]
  • “E-cigarettes damage brain, heart, lungs and blood vessels, study finds”, Irish Times – [link]

Image by Narupon Promvichai on Pixabay [link]


 Dave Cross
Article by Dave Cross
Freelance writer, physicist, karateka, dog walker