Health, UK (Commonwealth Union) – A recent study led by researchers at UCL and the University of Innsbruck reveals that individuals with limited smoking history who use e-cigarettes exhibit similar DNA changes in specific cheek cells as those who smoke traditional cigarettes.
This research represents a crucial step forward in deepening our comprehension of the potential long-term health effects of e-cigarettes. While it doesn’t directly establish a causal link between e-cigarette use and cancer, conducting studies with extended follow-up periods is essential for evaluating any harmful impacts of e-cigarettes and understanding their nature.
Published in Cancer Research, the study examined the epigenetic effects of both tobacco and e-cigarettes on DNA methylation across more than 3,500 samples. It explored the impact on cells directly exposed to tobacco, such as those in the mouth, as well as those not directly exposed, like blood or cervical cells.
Researchers of the study pointed out that epigenetics, an additional layer of information overlaying our genetic material (DNA), regulates how and when genetic programs are executed, akin to a computer’s software. Epigenomes, influenced by factors like aging, lifestyle, hormones, chemicals, and stress, can undergo modifications, including DNA methylation.
The research revealed significant epigenomic alterations in epithelial cells, commonly the origin cells for cancer, in the mouths of smokers. These changes were even more pronounced in lung cancers or pre-cancers compared to normal lung tissue, suggesting that smoking-induced epigenetic changes facilitate accelerated cell growth.
Notably, similar epigenomic changes were observed in the cells of e-cigarette users with minimal smoking history, defined as having smoked fewer than 100 tobacco cigarettes in their lifetime.
Dr. Chiara Herzog, the study’s lead author from UCL EGA Institute for Women’s Health and the University of Innsbruck, emphasized the novelty of the research, which investigated the impact of both smoking and vaping on various cell types, rather than solely focusing on blood samples. Furthermore, the study aimed to consider the potential long-term health implications of e-cigarette use.
“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.”
Via their computational analysis of the samples, the researchers also discovered that certain epigenetic alterations associated with smoking persist more robustly than others following cessation of smoking. This includes smoking-related epigenetic changes observed in cervical samples, an aspect previously unexplored.
Senior author Professor Martin Widschwendter, from UCL’s EGA Institute for Women’s Health and the University of Innsbruck, indicated that the epigenome serves as a historical record, shedding light on how our bodies reacted to past environmental exposures such as smoking. Moreover, delving into the epigenome holds promise for predicting future health outcomes and disease risks. Professor Widschwendter, further indicated that alterations identified in lung cancer tissue can also be detected in cheek cells of smokers who have not yet developed cancer.
He further emphasized that significantly, the study highlights that e-cigarette users display similar physiological changes, suggesting that these devices may not be as innocuous as previously believed. Longitudinal investigations into the effects of e-cigarettes are imperative. He added that they appreciate the support extended by the European Commission in facilitating the acquisition of these crucial data.
Tobacco is widely recognized as a modifiable factor contributing to adverse health consequences, with a global estimate of 7.69 million deaths attributed to it in 2019, a number projected to rise in the future. According to the NHS, e-cigarettes are considerably safer than traditional tobacco smoking, and smokers are encouraged to transition to vaping for better health outcomes.
The researchers involved in the latest study aim to delve deeper into how epigenetic alterations detected in cheek swabs from smokers could aid in identifying individuals at heightened risk of developing cancer. Additionally, they seek to evaluate the long-term health implications of e-cigarettes.
