Vaping ’causes the same DNA changes to cells as smoking’ and might lead to cancer, new research claims.
Scientists found similar DNA changes to cheek cells in people who vape but rarely smoke that are frequently cited as the origin of cancer among those who smoke tobacco.
Although the study doesn’t prove that vaping causes cancer – and though the practice is still considered safer than smoking tobacco – the new study raises questions about how harmful it is.
The study, from scientists at University College London and the University of Innsbruck in Austria, underpins the importance of future long-term studies of vaping to assess its adverse health consequences.
The research analysed the epigenetic effects of tobacco and e-cigarettes on DNA methylation in more than 3,500 samples to investigate the impact on cells directly exposed to tobacco – such as those in the mouth – and those not directly exposed, such as those in blood or cervical cells.
The epigenome refers to an extra layer of information superimposed on our genetic material, or DNA. Whilst DNA is compared to the hardware of a computer, epigenetics are comparable to the computer’s software; defining how, where and when the programmes used by the computer are run.
Our body’s genetic control system, known as the epigenome, can change due to various factors like ageing, lifestyle, exposure to hormones and chemicals, and even stress. Scientists often study a type of genetic modification called DNA ‘methylation’.
The researchers found that cells lining our organs, which are often where cancer starts, showed significant changes in smokers.
These changes were even more noticeable in lung cancers or pre-cancerous cells compared to normal lung tissue. This suggests that the genetic changes linked to smoking might make cells grow faster.
But the study, published in Cancer Research, also found similar changes in vapers who had smoked less than a hundred cigarettes in their lives.
Dr Chiara Herzog, from both the UCL EGA Institute for Women’s Health and the University of Innsbruck, said this doesn’t prove vaping causes cancer, but we can’t assume it doesn’t.
Dr Herzog, the lead author of the study, explained: “This is the first study to investigate the impact of smoking and vaping on different kinds of cells rather than just blood and we’ve also strived to consider the longer-term health implications of using e-cigarettes,”.
“We cannot say that e-cigarettes cause cancer based on our study, but we do observe e-cigarette users exhibit some similar epigenetic changes in buccal cells as smokers, and these changes are associated with future lung cancer development in smokers.”
“Further studies will be required to investigate whether these features could be used to individually predict cancer in smokers and e-cigarette users.”
“While the scientific consensus is that e-cigarettes are safer than smoking tobacco, we cannot assume they are completely safe to use and it is important to explore their potential long-term risks and links to cancer.”
“We hope this study may help form part of a wider discussion into e-cigarette usage – especially in people who have never previously smoked tobacco.”
The researchers also discovered through computer analysis of their samples that some smoking-related epigenetic changes remain more stable than others after quitting smoking – including those in cervical samples, something that has never previously been explored.
Professor Martin Widschwendter, from UCL’s EGA Institute for Women’s Health and the University of Innsbruck, who is a senior author of the study, said: “The epigenome allows us, on one side, to look back.”
“It tells us about how our body responds to a previous environmental exposure like smoking.”
“Likewise, exploring the epigenome may also enable us to predict future health and disease.”
“Changes that are observed in lung cancer tissue can also be measured in cheek cells from smokers who have not (yet) developed a cancer.”
“Importantly, our research points to the fact that e-cigarette users exhibit the same changes, and these devices might not be as harmless as originally thought.”
“Long-term studies of e-cigarettes are needed.”
Everyone knows that tobacco is a major cause of bad health.
In 2019 alone, it’s estimated that smoking caused 7.69 million deaths worldwide, and this number is expected to go up in the future.
Right now, the NHS says that e-cigarettes are much safer than smoking tobacco, and they suggest that smokers switch to vaping to get healthier.
The researchers at UCL want to do more research to see how changes in the cheek swabs of smokers could be used to find out who is most likely to get cancer, and to understand the long-term health risks of e-cigarettes.
Dr Ian Walker, from Cancer Research UK, backed the study’s authors in stressing the need for future research into the long-term health effects of vaping.
“This study adds to what we know about e-cigarettes, but it doesn’t prove that they cause cancer,” he said.
“We know from years of research that smoking causes cancer, and studies have shown so far that e-cigarettes are much less harmful than smoking and can help people stop smoking.”
“But this paper does remind us that e-cigarettes aren’t risk-free, so we need more studies to find out what their potential longer-term effects on our health might be.”
“Every single day in the UK, smoking tobacco causes 150 cases of cancer, which is why we’re keen to see the Government’s age of sale legislation presented in parliament.”
“There’s nothing that would do more to reduce the number of preventable deaths in the UK than ending smoking, and this policy will bring us one step closer to a smoke-free future.”
The study received funding from the European Union’s Horizon 2020 Research and Innovation programme, The Eve Appeal, and Cancer Research UK.
