A new study led by researchers from University College London (UCL) and the University of Innsbruck reveals that individuals who use e-cigarettes, despite having a limited history of smoking, undergo similar changes in DNA within certain cells of the cheek, comparable to those observed in smokers.
This study is an incremental step in helping researchers build a deeper understanding of the long-term effects of e-cigarettes on health. Although it does not show that e-cigarettes cause cancer, studies with long-term follow-up are important to assess whether e-cigarettes have harmful effects and, if so, what they are.
Understanding Epigenetic Effects
The study, published in Cancer Research, analyzed the epigenetic effects of tobacco and e-cigarettes on DNA methylation in over 3,500 samples, to investigate the impact on cells that are directly exposed to tobacco (e.g. in the mouth) and those that are not directly exposed (e.g. in blood or cervical cells).
The epigenome refers to an extra layer of information that is superimposed on our genetic material – the DNA. While DNA can be compared to the ‘hardware’ of a computer, epigenetics are comparable to the computer’s ‘software’ and define how, where, and when the programs used by the computer are run.
Epigenomes change throughout our lives and can be affected by a variety of genetic or nongenetic factors – including aging, our lifestyles, exposure to hormones, chemicals, and environmental factors, and even stress and psychological trauma. One commonly studied type of epigenetic modification is called DNA methylation.
The researchers found that epithelial cells (cells that typically line organs and are often the cells of origin for cancer) in the mouth showed substantial epigenomic changes in smokers. Importantly, these changes are further elevated in lung cancers or pre-cancers (abnormal cells or tissue that have the potential to develop into cancer), when compared to the normal lung tissue, supporting the idea that the epigenetic changes associated with smoking allow cells to grow more quickly.
The publication also includes new data showing that similar epigenomic changes were likewise observed in the cells of e-cigarette users who had only ever smoked less than 100 tobacco cigarettes in their lives.
Long-term Implications and Further Research
First author, Dr. Chiara Herzog (UCL EGA Institute for Women’s Health and University of Innsbruck), said: “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.”
Through their computational analysis of the samples, the researchers also found that some smoking-related epigenetic changes remain more stable than others after giving up smoking, including smoking-related epigenetic changes in cervical samples – something that has not previously been studied.
Senior author, Professor Martin Widschwendter (UCL EGA Institute for Women’s Health and University of Innsbruck), said: “The epigenome allows us, on one side, to look back. It tells us about how our body responded 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. We are grateful for the support the European Commission has provided to obtain these data.”
The Global Health Context
Tobacco is well known as a modifiable contributor to adverse health outcomes, and it has been estimated to have caused 7.69 million deaths globally in 2019, with numbers expected to increase in the future. The NHS says e-cigarettes are substantially safer than smoking tobacco and smokers are recommended to switch to vaping to improve their health.
The researchers involved in the latest study now hope to further investigate how epigenetic changes related to smoking in cheek swabs could be used for identifying individuals at highest risk of developing cancer and assessing the long-term health risks of e-cigarettes.
Dr. Ian Walker, Cancer Research UK’s executive director of policy, said: “This study contributes to our understanding of e-cigarettes, but it does not show that e-cigarettes cause cancer. Decades of research have proven the link between smoking and cancer, and studies have so far shown that e-cigarettes are far less harmful than smoking and can help people quit. This paper does however highlight that e-cigarettes are not risk-free, and so we need additional studies to uncover their potential longer-term impacts on human health.
“Smoking tobacco causes 150 cases of cancer every single day in the UK, which is why we look forward to seeing the Government’s age of sale legislation being presented in parliament. Nothing would have a bigger impact on reducing the number of preventable deaths in the UK than ending smoking, and this policy will take us one step closer to a smoke-free future.”
Reference: “Cigarette smoking and e-cigarette use induce shared DNA methylation changes linked to carcinogenesis” by Chiara Herzog, Allison Jones, Iona Evans, Janhavi R. Raut, Michal Zikan, David Cibula, Andrew Wong, Hermann Brenner, Rebecca C. Richmond and Martin Widschwendter, 19 March 2024, Cancer Research.
DOI: 10.1158/0008-5472.CAN-23-2957
This work was supported by funding from the European Union’s Horizon 2020 Research and Innovation program, The Eve Appeal, and Cancer Research UK.

News
The Role of Nanotechnology in Space Exploration
Nanotechnology, which involves working with materials at the atomic or molecular level, is becoming increasingly important in space exploration. By improving strength, thermal stability, electrical conductivity, and radiation resistance, nanotechnology is helping create lighter, more [...]
New Study Challenges Beliefs About CBD in Pregnancy, Reveals Unexpected Risks
CBD is gaining popularity as a remedy for pregnancy symptoms like nausea and anxiety, but new research suggests it may not be as safe as many believe. A study from McMaster University found that [...]
Does COVID increase the risk of Alzheimer’s disease?
Scientists discover that even mild COVID-19 can alter brain proteins linked to Alzheimer’s disease, potentially increasing dementia risk—raising urgent public health concerns. A recent study published in the journal Nature Medicine investigated whether both mild and [...]
New MRI Study Reveals How Cannabis Alters Brain Activity and Weakens Memory
A massive new study sheds light on how cannabis affects the brain, particularly during cognitive tasks. Researchers analyzed over 1,000 young adults and found that both heavy lifetime use and recent cannabis consumption significantly reduced brain [...]
How to Assess Nanotoxicity: Key Methods and Protocols
With their high surface area and enhanced physicochemical properties, nanomaterials play a critical role in drug delivery, consumer products, and environmental technologies. However, their nanoscale dimensions enable interactions with cellular components in complex and [...]
Nanotech drug delivery shows lasting benefits, reducing need for repeat surgeries
A nanotechnology-based drug delivery system developed at UVA Health to save patients from repeated surgeries has proved to have unexpectedly long-lasting benefits in lab tests – a promising sign for its potential to help human patients. [...]
Scientists Just Found DNA’s Building Blocks in Asteroid Bennu – Could This Explain Life’s Origins?
Japanese scientists detected all five nucleobases — building blocks of DNA and RNA — in samples returned from asteroid Bennu by NASA’s OSIRIS-REx mission. NASA’s OSIRIS-REx mission brought back 121.6 grams of asteroid Bennu, unveiling nitrogen-rich organic matter, including DNA’s essential [...]
AI-Designed Proteins – Unlike Any Found in Nature – Revolutionize Snakebite Treatment
Scientists have pioneered a groundbreaking method to combat snake venom using newly designed proteins, offering hope for more effective, accessible, and affordable antivenom solutions. By utilizing advanced computational techniques and deep learning, this innovative [...]
New nanosystem offers hope for improved diagnosis and treatment of tongue cancer
A pioneering study has unveiled the Au-HN-1 nanosystem, a cutting-edge approach that promises to transform the diagnosis and treatment of tongue squamous cell carcinoma (TSCC). By harnessing gold nanoparticles coupled with the HN-1 peptide, [...]
Global Trust in Science Is Stronger Than Expected – What’s Next?
A landmark global survey conducted across 68 countries has found that public trust in scientists remains robust, with significant support for their active involvement in societal and political matters. The study highlights the public’s [...]
Microplastics in the bloodstream may pose hidden risks to brain health
In a recent study published in the journal Science Advances, researchers investigated the impact of microplastics on blood flow and neurobehavioral functions in mice. Using advanced imaging techniques, they observed that microplastics obstruct cerebral blood [...]
AI Surveillance: New Study Exposes Hidden Risks to Your Privacy
A new mathematical model enhances the evaluation of AI identification risks, offering a scalable solution to balance technological benefits with privacy protection. AI tools are increasingly used to track and monitor people both online [...]
Permafrost Thaw: Unleashing Ancient Pathogens and Greenhouse Gases
Permafrost is a fascinating yet alarming natural phenomenon. It refers to ground that remains frozen for at least two consecutive years. Mostly found in polar regions like Siberia, Alaska, and Canada, permafrost plays a [...]
Frequent social media use tied to higher levels of irritability
A survey led by researchers from the Center for Quantitative Health at Massachusetts General Hospital and Harvard Medical School has analyzed the association between self-reported social media use and irritability among US adults. Frequent [...]
Australian oysters’ blood could hold key to fighting drug-resistant superbugs
Protein found in Sydney rock oysters’ haemolymph can kill bacteria and boost some antibiotics’ effectiveness, scientists discover An antimicrobial protein found in the blood of an Australian oyster could help in the fight against [...]
First U.S. H5N1 Death Sparks Urgency: Scientists Warn Bird Flu Is Mutating Faster Than Expected
A human strain of H5N1 bird flu isolated in Texas shows mutations enabling better replication in human cells and causing more severe disease in mice compared to a bovine strain. While the virus isn’t [...]