There is now solid evidence that e-cigarettes are less harmful than conventional cigarettes and are more effective in helping smokers to stop than nicotine gum or patches. But that does not mean e-cigarettes are harmless – and a great deal more research is needed – said speakers at The Virtual E-Cigarette Summit 2020 held from 3-4 December 2020, writes MedicalBrief.
Essentially, the message that came through from the Summit is that you are better off vaping than smoking – but if you do not smoke, then do not vape.
This is the eighth year that The E-Cigarette Summit has been hosted in the United Kingdom, the fourth year in Washington DC, and the first time it has been virtual. There were reportedly more than 40 experts presenting.
The Summit is independent, owned by Smooth Event Management and solely funded through delegate ticket sales. The E-Cigarette Summit does not accept sponsorship or funding from any outside organisation, commercial or government. Smooth Event says it has “no commercial links or involvement with the tobacco, pharmaceutical or electronic cigarette industry”.
There is a great change in public health related to tobacco, e-cigarettes and harm reduction. “For decades, the known harms from smoking and combustible products has aligned public health and tobacco control colleagues behind a known ‘enemy’,” say the Summit’s website.
“The emergence of less harmful alternatives has resulted in a heated debate that continues to divide scientists, health professionals and policy-makers.”
The E-Cigarette Summit says its aim is to facilitate respectful dialogue and thoughtful analysis of the latest research, and explore how the evidence should be interpreted, in order to deliver the effective health strategies to reduce smoking related death and disease.
The first session, on “The Scientific Evidence on E-Cigarettes”, was chaired by Professor Ann McNeill, a professor of tobacco addiction in the Institute of Psychiatry at King's College London, and deputy director of the UK Centre for Tobacco Control Studies.
McNeill stressed the importance of analysing evidence on tobacco products, especially e-cigarettes, and their role in stopping smoking, says a conference summary of the session. Since e-cigarettes are a relatively new product, surveillance is important to understand their use and repercussions for people and public health.
The Cochrane reviews are accepted as the gold-standard for investigating the best evidence of potential harms and benefits of healthcare interventions. Available evidence is systematically reviewed with a strong emphasis on quality.
Professor Jamie Hartmann-Boyce, senior research fellow in the Nuffield Department of Primary Care Health Sciences at the University of Oxford, leads the Cochrane review of electronic cigarettes for smoking cessation. First published in 2014, it is now a ‘living’ review funded by Cancer Research UK. She is also an editor for the Cochrane Tobacco Addiction Group.
Hartmann-Boyce told the Summit that a Cochrane update in October 2020 found increased evidence of benefits of e-cigarettes with nicotine when used to stop smoking. Still, many policymakers remain reluctant to encourage e-cigarettes for this purpose, citing ongoing uncertainty.
Helping with smoking cessation
One key Cochrane review of e-cigarettes finding is that e-cigarettes with nicotine help with long terms smoking cessation compared with nicotine replacement therapy. “This might translate to four additional successful quitters per 100 in absolute terms,” the session summary reports.
The evidence is inadequate to infer that e-cigarettes, in general, increase smoking cessation. The evidence suggests that e-cigarettes are substantially less harmful to health than smoking but are not risk free. Nicotine Replacement Therapy has been proven safe and effective, said Hartmann-Boyce.
It is difficult to generalise the risk to health of Electronic Nicotine Delivery Systems (ENDS), as compared with cigarettes or other tobacco products, as this is contingent on a range of factors. Both tobacco products and ENDS pose risks to health. The safest approach is not to use either.
It was important, she said, to evaluate scientific evidence on the impact of e-cigarettes on adult smoking cessation in the current context of the high level of e-cigarette use by young people, “which increased at unprecedented levels in recent years”.
From a population health aspect, according to the session summary, it was noted that one of the largest risk factors for starting smoking is having a parent who smokes, so any increase in quit rates will help to further reduce the number of people who take up smoking. There is an additional benefit from reduced exposure to second-hand smoke.
The scientific evidence regarding the effectiveness of ENDS as a smoking cessation is still being debated, said Hartmann-Boyce. “To date, in part due to the diversity of ENDS products and the low certainty surrounding many studies, the potential for ENDS to play a role as a population-level tobacco cessation intervention is unclear.”
Absolute and relative risks
Professor Alan Boobis OBE, Emeritus Professor of Toxicology at Imperial College, spoke on the “Absolute and relative risks of electronic cigarettes”. He chairs the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT), an independent scientific advisory committee.
COT recently reviewed risks to human health from chemicals alone and in combination present in, and formed during the use of, e‐cigarettes. The work was initiated in 2016 and was at the request of the UK Department of Health and Social Care and Public Health England.
Boobis concluded that e-cigarettes are not without risks. The effects of chemicals in e‐cigarettes will depend not only on their toxicity but also on the amount present.
“The evidence suggests that the risk posed by e‐cigarettes to users is substantially less than that posed by conventional cigarettes, but at present we cannot quantify precisely by how much less.” Risks vary, he said. Risks to bystanders are low to very low.
“The toxicity of ENDS is only one part of the complex risk‐benefit assessment necessary to determine their role in public health,” he concluded.
Lack of evidence of respiratory harm
Professor Sanjay Agrawal, a professor of respiratory science in the Institute of Lung Health at the University of Leicester and chair of the Tobacco Special Advisory Group at the Royal College of Physicians, spoke on “The pulmonary effects of e-cigarettes”.
There have been attempts to quantify the risks posed by inhalants, and to come up with sensible policy recommendations and advice on the relative risks and benefits. Agrawal’s investigations led him to multiple conclusions. One is that there is no available evidence on whether or not e-cigarettes cause respiratory diseases in humans, according to the session summary.
There is limited evidence for improvement in lung function and respiratory symptoms among adult smokers with asthma who switch to e-cigarettes completely or in part (dual use). There is also limited evidence for reduction of chronic obstructive pulmonary disease (COPD) exacerbations among adult smokers with COPD who switch to e-cigarettes completely or partly.
There is moderate evidence for increased cough and wheeze in adolescents who use e-cigarettes, and an association with e-cigarettes use and an increase in asthma exacerbations.
There was, Agrawal concluded, plausible risk of airways disease, hypersensitivity pneumonitis, lung cancer and pulmonary fibrosis – but less than with tobacco use.
He advises strategies to mitigate the uptake of e-cigarettes among adolescents, to optimise the treatment of tobacco dependency, to diminish potential health harms, and proportionate regulations that weigh risks and benefits along with vigilance and research.
The E-Cigarette Summit – Science, Regulation and Public Health