HMN 2026: How Vaping helps some people ditch cigarettes but may come with its own lung cancer risk

Vapes or e-cigarettes were marketed as a safer, smokeless alternative to traditional cigarettes and even promoted as a tool to help smokers quit. Their fruity flavors and sleek designs further reinforced the perception that they were a less harmful substitute for conventional tobacco products. While quitting smoking is known to reduce cancer risk over time, growing evidence suggests that switching to e-cigarettes may not be as harmless.

In a recent study published in Nature Medicine, researchers analyzed health data from more than 4.5 million people in South Korea to investigate whether using e-cigarettes after quitting smoking was associated with an increased risk of lung cancer and death from the disease.

Turns out, making the switch wasn’t as protective as many might expect. Compared to people who quit smoking entirely, those who switched to e-cigarettes faced a significantly higher risk of developing and dying from lung cancer. They had a 56% higher risk of getting lung cancer and were twice as likely to die from it. However, switching to vapes or e-cigarettes still led to better outcomes than continuing to smoke regular cigarettes.

Risk in a benign disguise

Lung cancer is the leading cause of cancer cases and deaths among men and women. There are an estimated 2.5 million new cases globally and 1.8 million people lost their lives to this disease in 2022 alone.

While many causes of lung cancer are beyond people’s control, smoking is one risk factor one can do something about. A large body of studies point to the fact that quitting smoking can make a real difference.

The risk grows with how much and how long a person smokes, with current smokers at higher risk than former smokers. E-cigarettes took advantage of this and then swooped in with a compelling promise: a safer alternative to traditional smoking.

Since they don’t burn tobacco, they were widely seen as less harmful, a perception that led some countries and even health experts to promote them as a tool to help people quit smoking.

Lung cancer takes years, sometimes decades, to develop, which has made it really hard to know what vaping does to the body over time. Most studies captured only short-term effects, such as a persistent cough or an irritated throat. Researchers needed to find out if they are truly as safe as people think in the long run.

To answer this question, researchers turned to a massive dataset from South Korea’s National Health Screening Program. The study included 4,524,895 people and drew on health screenings available for all employees aged 20 and older and all other citizens aged 40 and older.

By tracking data collected from participants over several years, the researchers examined how smoking and vaping habits shaped lung cancer outcomes. They grouped participants into current smokers, short-term quitters, and long-term quitters, while also taking a closer look at the high-risk group consisting of adults aged 50 to 80 years.

The data showed that the longer people stayed away from cigarettes, the more their lung cancer risk fell, but vaping interrupted that progress. Long-term quitters, those who had been cigarette-free for five or more years, had a significantly higher lung cancer risk if they vaped compared to those who did not.

Even short-term quitters, those who were off cigarettes for less than five years, saw their risk reduction dwindle when they switched to e-cigarettes. For the high-risk group, switching to e-cigarettes was linked to a 91% higher risk of developing lung cancer and 92% higher chance of death from it, when compared to those who quit completely.

The researchers also highlight that vapes are not chemically benign. They contain cancer-causing substances like formaldehyde and toxic metals such as lead, nickel, and chromium. They emphasize that while the study couldn’t prove that vaping directly causes lung cancer, it exposed the fact that vaping after quitting smoking may chip away at some of the lung cancer benefits gained from quitting altogether.

The data presented in this study can help clinicians and public health experts reframe the common narrative that portrays e-cigarettes as a safe option for former smokers who are considering or already using them as a long-term substitute for cigarettes.

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