A study of 4.5 million people suggests that ex-smokers who switch to e-cigarettes have a higher risk of dying from lung cancer than those who quit smoking without using these devices. But using e-cigarettes is still much better than continuing to smoke.
Smokers who give up traditional cigarettes but continue to use e-cigarettes are likely to more than 50% higher of developing lung cancer than those who completely abandon the habit, according to a study of more than 4.5 million people.
Still, research highlights that turning to e-cigarettes to help quit smoking is safer than continuing to smokecomes out to .
“The study adds to the rapidly growing body of evidence that Electronic cigarettes are not at all risky as initially stated”, says Becky Freemanfrom the University of Sydney, Australia, who did not participate in the , published this week in Nature Medicine.
“It is important that people who are trying to quit smoking try other safer but effective methods firsts, and that they only turn to electronic cigarettes after they have exhausted other options, if they are unable to stop smoking”, adds the researcher.
Little more than 40% two non-UK smokers Those who quit tobacco in 2024 turned to e-cigarettes to help with the process, and 20% of ex-smokers continued to use them a year or more after quitting tobacco.
Although some argue that e-cigarettes can help people successfully quit smoking, these devices have been linked to airway irritation, reduced lung function and, in animal studies, lung cancer.
To better understand its effects on humans, Yeon Wook Kim, of Seoul National University in South Korea and colleagues followed more than 4.5 million adult smokers who participated in the Korean National Health Screening Program between 2018 and 2023.
Participants were classified as current smokersex-smokers short term (who had not smoked since at least 2018) or former long-term smokers, who had not smoked since at least 2014.
Between 2018 and 2023, 35,887 cases of lung cancer and 12,807 disease-related deaths between participants.
When researchers analyzed this data by participant group and self-reported e-cigarette use, they concluded that the risk of death from lung cancer was substantially higher. among former smokers who used electronic cigarettes than among those who did not use them.
“Compared to those who quit cigarettes completely, individuals who used e-cigarettes after quitting had a 56% higher risk”, knee Kim.
More extensive studies are still needed, but some of the chemicals present in e-cigarettes have been linked to damage us not dna.
The use of these devices has also been related to the so-called oxidative stress (an imbalance between free radicals and antioxidants in the body, which causes cellular damage), epigenetic changes (changes in the way genes are influenced by the environment) and inflammation in respiratory and oral tissues.
Kim and his team emphasize, however, thatand they couldn’t prove it that the use of electronic cigarettes, alone causes lung cancerand that more studies are needed that include people outside of South Korea.
The researchers also found that the risk of death from any cause was significantly lowest among ex-smokers who used electronic cigarettes than among current smokerswhich reinforces the already well-established general benefits of quitting smoking.
Second Nicole Leefrom Curtin University, in Perth, Australia, the study suggests that completely abandon both tobacco and electronic cigarettes offers greater protection against lung cancer than quitting smoking but continuing to use these devices. “The conclusions are very relevant for people who have stopped smoking”, he says.
“This doesn’t change the advice given to smokers: quitting smoking completely is the safest option. But if you can’t quit smoking without using e-cigarettes, or don’t want to, swap tobacco for e-cigarettes remains safer,” says Lee.
“Electronic cigarettes are not harmlessbut as a harm reduction strategy, they are much better than continuing to smoke.”
Bernard Stewartfrom the University of New South Wales in Sydney, adds that more studies are needed before public health measures, such as new restrictions on e-cigarettes, are advanced.
