If you're trying to quit smoking, you'll have probably heard talk that switching to e-cigarettes – or vapes – is a healthier option.
One study by researchers at University College London estimated that in 2017 alone, over 50,000 people stopped smoking thanks to their use of e-cigarettes.
It’s true that most of the compounds that cause smoking-related diseases aren’t found in e-cigarettes (which, unlike heated tobacco products, don’t burn tobacco), so vaping is safer in that sense. But if you’ve never been a smoker, it’s not advisable to take up vaping.
The e-liquid that’s used in vapes typically contains a mix of propylene glycol and glycerine.
Both compounds are considered safe to ingest and though they haven’t been officially labelled safe for inhalation, a 2020 review of clinical studies found “little impact on lung functions, as well as no significant inflammatory effects.”
Added to this mix are various synthetic flavourings, which, in order to comply with the regulations of the country they’re being sold in, must be considered safe for use as ingredients in foodstuffs (though not necessarily for inhalation).
Many e-cigarettes also contain nicotine, which is helpful for those trying to quit smoking without suffering withdrawal symptoms, but could be addictive for new users and has been linked to lung cancer in mice.
Anyone who’s ever peeked into a vape shop will know there are hundreds, if not thousands, of flavours available. There are the ‘traditional’ flavours of tobacco and menthol, but also fruit and citrus flavours, and even e-liquids that mimic baked goods.
Studies have suggested that fruit flavours may be the worst vape flavours for your health. Research on cell samples from 2016 associated strawberry flavour with higher cell toxicity, meaning it could cause more cellular damage.
More recently, a 2019 study linked fruit flavours to the presence of two compounds, acrylonitrile and acrolein, which are known to have carcinogenic potential and can cause lung irritation.
One study published in 2024 found that inhalation of berry-flavoured e-cigarette vapour effectively paralysed the immune cells in the lungs of mice. When these mice were then exposed to harmful bacteria, their cells struggled to clear the infection.
Compared with healthy controls, the vape-exposed mice had a lower survival rate and those that did survive took longer to recover from their infection.
This doesn’t mean the non-fruit flavours are 100-per-cent safe, however.
The chemicals in e-liquids can be unstable, so they can react to form new compounds when they’re heated by the e-cigarette to form the breathable vapour.
One group, the aldehydes, are commonly used as flavourings in vanilla, cherry and cinnamon vapes, but chemical reactions within the e-cigarette can create acetals, which are known respiratory irritants.
There may be other chemical reactions occurring between other flavours that we haven’t yet identified: this area of research is still very young, especially compared to the wealth of knowledge available about smoking and its effects on people’s health.
So, while e-cigarettes are often recommended to those who are trying to quit smoking, there are risks involved with taking up vaping. If we know anything, it’s that we still don’t completely understand what vaping does to the body.
This article is an answer to the question (asked by Huey Robins, via email) 'Which vape flavour is worse for you?'
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