The claim that vaping is 95% less harmful than smoking cigarettes dates back to 2015 and while it might be useful to communicate that e-cigarettes are less harmful, the statistic can’t be proven definitively.
Available evidence does suggest vaping is less harmful to health than smoking – but it is not risk free.
While early data indicates vaping is a more effective way to quit smoking than other methods, it also hasn’t been proven to be the best way.
“Vaping is at least 95% less harmful than smoking but not safe, healthy,” reads a headline on South African news site Independent Online (IOL).
The April 2022 article was reporting on what it said was “an evidence update on the growing fad” by Public Health England (PHE), a UK health agency that was replaced by two other agencies in October 2021.
In 2015 PHE reported that “an expert review of the latest evidence concludes that e-cigarettes are around 95% safer than smoked tobacco and they can help smokers to quit”.
Africa Check also evaluated the claim in 2017 and found that more research was needed.
IOL also reported that vaping was “the most effective way for smokers to quit when compared with other methods”.
E-cigarette use, commonly called “vaping”, is fast becoming a popular alternative to cigarette smoking.
When people smoke a cigarette, they inhale nicotine – the addictive constituent in tobacco – and other chemicals released by combustion.
E-cigarettes work by heating up a mixture of nicotine-containing liquids until they “vaporise” and can be inhaled. Vaporisers – more commonly called vapes – can also be nicotine-free.
The process of combustion produces chemicals, many of which are harmful to humans. Vape companies often use this as the clincher – “no combustion, no problem” – and market their products as healthier alternatives to cigarettes.
But is it that simple?
Harms associated with vaping
Since the invention of e-cigarettes in 2003, scientists have been studying the effects of vaping on the human body. While there is a great deal more research about tobacco, available research suggests that regular vape use could also have harmful effects, with links to asthma, chronic lung disease, strokes and heart attacks.
Researchers also say that e-cigarette liquids often contain a range of chemicals, many of which have not been well-researched and could be harmful. In recent years, some scientists have raised concerns about the increase in e-cigarette use among young people.
Vaping products also vary. In 2019, the US Centers for Disease Control and Prevention (CDC) reported an outbreak of e-cigarette or vaping use-associated lung injury, or EVALI. The outbreak was responsible for 3,000 cases of injury and 68 deaths.
Once the particular chemical responsible for this was identified and removed from illegal vape products, EVALI cases declined rapidly, Clive Bates told Africa Check. He is a British public health advocate who has worked in tobacco policy for decades.
Evidence shows vaping is safer than smoking
Bates told Africa Check that the “at least 95% safer than smoking” claim is not an exact measurement but a “risk communication”. It gives health professionals and the public a sense of how large the difference in risk is likely to be, without implying that there is no risk to vaping at all.
Public Health England and the Royal College of Physicians (RCP) have continued to evaluate the evidence in the years after the original analysis, producing “extensive reviews in 2015 and 2016, with PHE updating its statement in 2018”.
Some research has examined the possible longer-term effects of vaping compared to smoking. One November 2021 review summarised recent studies that looked at biomarkers, or biological signals, in vapers’ bodies that were usually associated with smoking-related diseases.
The authors found that vaping was likely to be far less harmful than smoking, when looking at biomarkers for developing respiratory diseases, cancer and cardiovascular problems. Based on this, they estimated vaping was, at most, one third as harmful as smoking.
Impossible to give a precise point estimate
So vaping is safer than smoking, but is it at least 95% safer?
RCP says the harm from vaping long-term is “unlikely to exceed 5% of the harm from smoking tobacco” while according to PHE, the claim that the habit is “at least 95% less harmful than smoking remains a good way to communicate the large difference in relative risk unambiguously”.
This statistic was still a judgement, Bates said: “In practice, it is impossible to give a precise point estimate.”
So while available evidence does suggest vaping is safer than smoking, the claim that it is at least 95% less harmful is not a direct measurement of harm and remains unproven.
The IOL article also quotes Asanda Gcoyi, the chief executive of the Vapour Products Association of South Africa. She said that “based on several reviewed studies, vaping had been proven to be the most effective way for smokers to quit when compared with other methods”.
Africa Check contacted Gcoyi to find out more. She directed us to reviews that summarised the results of studies conducted in the last few years, and largely supported the claim. These included reviews of randomised controlled trials (RCTs), which are considered the gold standard of medical research.
Two of the reviews found that vaping was more effective for quitting smoking than other methods, including nicotine replacements like patches or chewing gum. A 2021 report by PHE found that across multiple reviews, vaping was more or equally as effective as other tools.
The most recent studies lean in favour of vaping being a more effective way to quit smoking when compared with nicotine replacements. But more research, including in lower income countries, would allow researchers to draw conclusions about whether vaping is the most effective way to quit smoking. The claim is therefore also unproven.
South African study contradicts other research – but has limitations
Most available reviews have included a large amount of data from thousands of people. But nearly all have been from high-income countries in Europe and North America.
Can we apply their results to African contexts? One South African study conducted in 2018 surveyed more than 18,000 people in an online questionnaire.
Lekan Ayo-Yusuf, one of the study’s authors and an expert on tobacco control research, told Africa Check this was one of the largest peer-reviewed studies of people who vape outside of the US and UK.
Participants were asked questions about their smoking and vaping habits and attitudes. Researchers found that people who had tried to quit smoking and intended to quit again had higher chances of relapsing into smoking if they had some vaping experience. This appears to contradict results from studies in other parts of the world.
But there were various limitations in the study’s design. First, it was not a randomised controlled trial (RCT), which allows researchers to determine cause and effect. The authors acknowledge this as a limitation, saying only associations between vaping and smoking can be drawn.
Because of this, there could be other reasons for the main finding. For example, sometimes the people who vape are also those who smoke more heavily in the first place. This could explain why vapers in this study had more trouble quitting. It could be because they were more dependent on nicotine to begin with, not just because they used e-cigarettes, said Clive Bates, a public health advocate who has worked in tobacco policy for decades. This is a well-known issue in this type of research, known as “confounding by indication”.
The study also did not actually ask whether participants were using e-cigarettes in order to quit smoking. Bates told Africa Check that unlike nicotine patches or gum, e-cigarettes are not only used to quit smoking.
The researchers defined a “quit attempt” as when someone believed e-cigarettes could be used for quitting, and also used e-cigarettes. But it was “perfectly possible to be using e-cigarettes without an intention to quit [smoking], while believing … they can be used for quitting,” Bates said.
While acknowledging some of these limitations in the study, Ayo-Yusuf told Africa Check that “these population studies are as important as randomised clinical trials” in order to provide “evidence of … effectiveness in real world settings”.