New research involving more than 4.5 million individuals indicates that former smokers who subsequently take up vaping may face a significantly increased risk of dying from lung cancer. The study found that ex-smokers who used e-cigarettes had a 56% higher chance of lung cancer mortality compared to those who ceased smoking entirely without the use of vaping products. This adds to a growing body of evidence questioning the long-term safety profile of e-cigarettes.
The comprehensive study, conducted by Yeon Wook Kim and colleagues at Seoul National University in South Korea, analysed data from participants in the Korean National Health Screening Programme between 2018 and 2023. Participants were categorised into current smokers, short-term quitters, and long-term quitters. Over the five-year period, the study identified 35,887 cases of lung cancer and 12,807 related deaths among the cohort, allowing researchers to examine the correlation between vaping status and lung cancer outcomes.
While the findings highlight a concerning link, the researchers were keen to stress that the study could not definitively prove that vaping directly causes lung cancer. They also pointed out the necessity for further, longer-term research, particularly studies that include populations beyond South Korea, to fully understand the implications. Some of the chemicals found in e-cigarettes have previously been associated with DNA damage, oxidative stress, epigenetic changes, and inflammation in respiratory and oral tissues, as noted by experts not involved in this specific research, such as Becky Freeman from the University of Sydney.
Crucially, the study also reinforced the overwhelming health benefits of quitting smoking. It found that the risk of death from any cause was significantly lower among ex-smokers who used e-cigarettes compared to current smokers. This aligns with current public health advice, including that from the NHS, which generally supports e-cigarettes as a less harmful alternative for those struggling to quit traditional cigarettes, although not entirely risk-free. In the UK, around 40% of smokers who quit in 2024 used e-cigarettes to aid the process, with 20% of ex-smokers continuing to vape a year or more after giving up combustible tobacco.
Nicole Lee from Curtin University in Perth, Australia, commented on the study's message, stating that completely stopping both smoking and vaping offers the greatest protection against lung cancer. However, she reiterated that for individuals unable to quit smoking without assistance, switching to vaping remains a significantly safer option than continuing to smoke. Bernard Stewart from the University of New South Wales added that more studies are required before any new public health policies, such as further restrictions on vapes, are implemented.
For UK patients, this research provides additional context to the ongoing debate surrounding vaping. While the NHS continues to advise that vaping is considerably less harmful than smoking tobacco, this study suggests that the ideal outcome for health is to cease both activities entirely. Individuals seeking to quit smoking are encouraged to explore all available options and consult healthcare professionals.