How Quitting Cigarettes and Vaping Can Reduce Cancer Risks After Smoking

A comprehensive study involving over 4.5 million participants reveals that smokers who switch to vaping after quitting traditional cigarettes face a more than 50% higher risk of developing lung cancer compared to those who quit smoking entirely. Nonetheless, the findings indicate that using e-cigarettes can be a safer alternative than continued smoking.

“This research contributes to the increasing body of evidence that e-cigarettes are not as low-risk as initially suggested,” states Becky Freeman from the University of Sydney, Australia, who was not involved in the study. “It’s crucial for individuals trying to quit smoking to seek safer alternatives first and only resort to e-cigarettes as a last resort.”

In the UK, over 40% of smokers attempting to quit in 2024 reported using e-cigarettes. Approximately 20% of ex-smokers continued using e-cigarettes more than a year after quitting. While some claim e-cigarettes effectively aid in quitting, studies have linked them to airway inflammation, reduced lung function, and lung cancer in animals.

To assess the long-term effects on human health, researchers from Seoul National University, including Kim Young Wook, monitored over 4.5 million adult smokers involved in South Korea’s National Health Checkup Program from 2018 to 2023.

Participants were divided into categories: current smokers, short-term quitters (those who halted smoking since at least 2018), and long-term quitters (those who stopped smoking since at least 2014). Between 2018 and 2023, 35,887 participants developed lung cancer, leading to 12,807 related deaths.

The data analysis indicated that ex-smokers who vaped faced a significantly elevated risk of lung cancer-related mortality compared to non-vaping ex-smokers. “Those who vaped after quitting had a 56% higher risk of death from lung cancer compared to individuals who quit smoking altogether,” said Kim.

While more extensive research is essential, some chemicals in e-cigarettes have been linked to DNA damage. Vaping is also associated with oxidative stress, epigenetic changes, and inflammation of respiratory and oral tissues.

However, Kim’s team emphasizes that conclusive evidence linking e-cigarettes directly to lung cancer is lacking, necessitating further research beyond South Korea.

Additionally, the research found that ex-smokers who switched to e-cigarettes had a lower overall mortality risk than current smokers, reinforcing the health benefits of quitting smoking entirely.

Nicole Lee from Curtin University in Perth, Australia, suggests that the study’s implications indicate that quitting both smoking and vaping is more effective for lung cancer prevention than merely reducing smoking. “This study is crucial for those who have quit smoking,” she states.

“Our recommendation remains that total cessation of both smoking and vaping is the safest route. However, if one struggles to quit entirely, transitioning to e-cigarettes is a preferable alternative,” Lee explains, noting its role as a harm reduction strategy compared to continued smoking.

Bernard Stewart, a professor at the University of New South Wales in Sydney, highlights the necessity for further research before implementing comprehensive public health strategies related to e-cigarette regulation.