Vaping much less harmful to lungs than smoking, review confirms
Posted on August 7, 2019
A comprehensive review of the effects of vaping on the lungs has confirmed that vaping is much less harmful than smoking. The findings are in line with the advice from the British Lung Foundation and reflect the real-world experience of millions of users.
The review by an international team led by Professor Riccardo Polosa was published this week in the journal Expert Review of Respiratory Medicine. The findings are important because the respiratory tract (throat, airways and lungs) is the primary target of any potential harm from vaping.
The findings are not surprising as the analysis of aerosol shows it has far fewer chemicals than cigarette smoke and those present are at much lower levels.
The review found that many studies are poorly designed and results can be misleading. Importantly, many cell and animal studies do not compare the effects of vaping to those of smoking and present findings which are hard to interpret. This has resulted in many sensational and deceptive media headlines.
Human studies provide the most relevant data on the effects of vaping on the respiratory tract and confirm that vaping is unlikely to cause significant health concerns under normal use. Several studies have demonstrated benefits for smokers switching to vaping.
- Improvements in symptoms (cough, phlegm, etc.)
- In asthma, 'progressive significant improvement'
- In COPD (emphysema), reduced symptoms, fewer infections, improved breathing and exercise capacity
- No studies reported serious adverse events, which is consistent with the real world experience with vaping.
Cell and animal studies
The authors say that cell and animal studies 'are not robust indicators of the potential health risks of using e-cigarette' and have 'limited value'. The dosing and exposure to vapour often does not match normal vaping behaviour in humans. Furthermore, many studies do not compare the effects of vapour to smoking, so are hard to interpret.
Animal studies, mostly in rodents, shows that vaping can cause respiratory irritation, inflammation, oxidative stress and impairment of the immune defences. However, how these changes translate to humans is uncertain.
Studies which expose cells to aerosol have shown some potential effects but these are much less than from smoking when both vapour and smoke are compared.
Studies which expose cells to e-liquid (instead of vapour) are less useful. These studies 'do not represent exposures under normal conditions of use' and 'their relevance is questionable'.
A note of caution
The report acknowledges that very little is known about the long-term health effects of vaping. 'Only large long-range prospective studies of vapers who have never smoked can provide definitive data to demonstrate any potential impacts regular use of vaping products may have on long term health'.
For this reason, vaping is only recommended to adult smokers who are otherwise unable to quit. It is also recommended that vapers stop vaping once they are confident of not relapsing to smoking to avoid unnecessary risk.
Posted by Colin Mendelsohn, firstname.lastname@example.org