Vaping may reduce respiratory infections for ex-smokers: study

London: Smokers who successfully switch to vaping may have fewer respiratory infections, a new study has claimed. An on-line survey of 941 respondents assessed subjective changes in respiratory symptoms in smokers who switched to vaping for at least two months.

The results showed that 66 per cent of respondents reported an improvement in respiratory symptoms, 29 per cent reported no change and 5 per cent reported worsening. "There is no doubt that e-cigarettes are much safer than conventional cigarettes, but smokers are still led to believe that they're dangerous," said Professor Peter Hajek from Queen Mary University of London (QMUL).

"This misinformation includes a misreported study on rats that claimed that vaping may increase vulnerability to infections. These new findings from human vapers show that this is not the case," said Hajek. "The study needs to be interpreted with caution because it is based on self-reported data, and further studies using objective measures are needed," he said.

"However, the present results provide sufficient information to suggest that vaping does not increase infection rates and may in fact lead to a decrease in infections," he added. Some previous cell and animal studies have been interpreted as suggesting that vaping may increase vulnerability to infection, but these studies did not use realistic exposure levels, researchers said.

Human trials have reported no significant adverse respiratory effects associated with e-cigarette use for up to 1.5 years and a follow-up study of smokers with asthma who switched to vaping found significant improvements. It is not surprising that the survey respondents noticed improvements in their respiratory health, researchers said.

This is because smoking increases susceptibility to respiratory infections and stopping smoking can be expected to have a positive effect. Vaping may also provide some antimicrobial protection through the e-liquid ingredient propylene glycol, though further evidence is needed to confirm this, researchers said. The main limitation of the study is that the reports are subjective.

Future studies should assess respiratory symptoms objectively and on unselected samples of vapers. Despite the limitations, researchers said that the study provides a reasonable reassurance that vaping does not promote
respiratory infections and may in fact reduce them. The study was published in the Journal of Addiction Research and Therapy.