By Angus Dalton
Examine, a free weekly newsletter covering science with a sceptical, evidence-based eye, is sent every Tuesday. You’re reading an excerpt – sign up to get the whole newsletter in your inbox.
Hello, this is science reporter Angus Dalton. Welcome to Examine.
Nicotine poisoning, seizures and burns are frequently cited as short-term risks of vaping. But in light of the nationwide ban on disposable vapes – brightly coloured, palm-sized and as easy to acquire as a packet of Twisties – what do we really know about long-term health effects?
Health Minister Mark Butler announced a ban on disposable vapes last week.Credit: iStock
The view, like a plume of cherry-scented vapour, is rather hazy.
The 95 per cent claim
“In God we trust,” proclaims Macquarie University Professor of Respiratory Medicine Matthew Peters. “Everybody else bring data.”
That’s his response to a statement released by Public Health England in 2015 that claimed vaping is 95 per cent safer than smoking, based on an independent review by experts convened by the health authority.
“The 95 per cent claim was never rooted in any evidence,” Peters tells me. “It’s just an opinion of a few people who got together around a table nine years ago. And it’s sort of carried through the English mythology.”
Peters cites a 2020 Italian study that followed about 900 people split between tobacco smokers, e-cigarette users (vapers) and those who did both. Over six years, about 10 per cent of the study group had some kind of smoking-related health event, such as a heart attack or lung problems. There was no evidence of harm reduction for those who had swapped from cigarettes to vaping.
“In six years, we have not even seen 1 per cent of the supposed 95 per cent reduction,” Peters says. “So when’s it going to kick in?”
The lack of long-term data
Respiratory disease researcher Professor Brian Oliver says his team, from UTS and the Woolcock Institute of Medical Research, were among the first to flag the dangers of vaping in Australia in 2020.
They scrutinised advice offered by obstetricians in the UK and Europe that urged women who smoked to swap to vaping during pregnancy.
Oliver and his team exposed pregnant mice to vapor from e-cigarettes for six weeks before mating, through gestation and lactation.
“The offspring were born with chronic lung inflammation, the kidneys are not very good, the liver’s not very good, there are neurological complications associated with vaping during pregnancy,” Oliver says.
E-cigarettes were no longer seen as being something safe to be used during pregnancy.
Oliver says not everyone accepts animal research, but about 20 other groups around the world have conducted similar studies, and “every group’s found a detrimental effect of e-cigarette use during pregnancy.”
“If you add all of that information together, I think it’s highly likely you’d see very similar effects in humans.”
Oliver says it is necessary for researchers to use animal and cellular studies in lieu of long-term health data from people who vape.
Bright colours and flavoured nicotine, like mint, strawberry and mango, have attracted young users.Credit: AAP
“If somebody smokes it may take 20 or 30 years for disease to manifest. So with electronic cigarettes, you couldn’t do a simple clinical study and watch people for six months and then work out whether they’re good or bad. You’d have to watch them almost for a lifetime.”
Peters agrees. “We should rely on our advanced molecular science and genetic studies to predict these things and act on predictions, rather than – as in the 1950s [with smoking] – wait for people to be dying from a range of cancers.”
A recent systematic review of 400 global studies into vaping was published in The Medical Journal of Australia in March.
The review found there was conclusive evidence that linked vaping to poisoning, risk of seizures and lung injury, and substantial evidence that vaping can cause non-smokers to become addicted to nicotine – all effects that emerge in the short term.
As for long-term impacts on cardiovascular disease, cancer, mental and reproductive health? The evidence on the effect of vaping was “insufficient or unavailable”, the review found.
Does vaping help smokers quit?
The review, led by epidemiologist Professor Emily Banks AM, also found there was limited evidence that e-cigarettes help people quit smoking.
But Emeritus Professor Wayne Hall, director of the Centre for Youth Substance Abuse Research at the University of Queensland, begs to differ. He believes that “tabloid headlines” have led to a heavy-handed approach to vaping regulation and that the government should make sure smokers can easily access vapes.
Hall cites a Cochrane Review – regarded as the gold standard of evidence – that found e-cigarettes work better than nicotine gum and patches in helping people quit.
But many people who quit smoking by using e-cigarettes continue to vape. In one study, 886 people were randomly assigned either e-cigarettes or nicotine replacement products (i.e. patches and gum) in their efforts to quit smoking.
Eighteen per cent of the vapers quit smoking after a year compared with 9.9 per cent of the other group. But 80 per cent of the e-cigarette users who quit smoking were still vaping after 52 weeks, while only 9 per cent of the quitters in the other group were still using nicotine replacement treatments.
“A substantial number of smokers will switch from smoking to vaping,” Hall says. “What we don’t know are the long-term health risks of that, compared with smoking, but it’s almost certainly going to be a lot less given the much, much lower burden of carcinogens and toxins in vapes than in cigarette smoke.”
Enjoyed this article? The Examine newsletter explains and analyses science with a rigorous focus on the evidence. Sign up to get it each week.