Millions of people around the world have turned to e-cigarettes in recent years. Many smokers see vaping as a stepping stone away from cigarettes or as a safer long-term alternative.
Unlike traditional cigarettes, e-cigarettes do not burn tobacco. Instead, they heat a liquid that users inhale as a vapor. Because there is no smoke, vaping has often been presented as a much less harmful choice.
This idea has been appealing to smokers who want to improve their health without giving up nicotine entirely. Public health discussions in some countries have even supported the use of e-cigarettes as a way to help smokers quit. However, scientists have repeatedly warned that less harmful does not necessarily mean harmless.
A major new study published in Nature Medicine suggests that former smokers who switch to e-cigarettes may still face a significantly higher risk of lung cancer compared with people who quit smoking completely.
Lung cancer remains the leading cause of cancer deaths worldwide. It kills more people than any other form of cancer and often has a poor survival rate because it is frequently diagnosed after the disease has already advanced.
Smoking is the biggest avoidable cause of lung cancer, which is why quitting smoking has always been one of the most important ways to reduce risk.
The problem is that lung cancer usually develops slowly. The disease can take many years to appear, making it difficult to study the long-term effects of newer products such as e-cigarettes.
Most earlier research on vaping focused on short-term symptoms, including throat irritation, coughing, and breathing problems. Scientists needed very large studies that could track people for many years to better understand the possible long-term consequences.
Researchers in South Korea took advantage of one of the world’s largest health databases. They analyzed information from the National Health Screening Program and studied more than 4.5 million people.
The researchers compared people who continued smoking, people who quit smoking completely, and people who switched to e-cigarettes after quitting cigarettes.
The findings showed a clear pattern. People who stayed away from cigarettes completely had the greatest reduction in lung cancer risk. In contrast, former smokers who switched to e-cigarettes had a significantly higher risk of developing lung cancer and dying from it.
Compared with people who quit smoking entirely, former smokers who used e-cigarettes had a 56 percent higher chance of developing lung cancer. They were also twice as likely to die from lung cancer.
Even though vaping was still associated with better outcomes than continuing to smoke cigarettes, it did not provide the same level of protection as completely quitting nicotine products.
The researchers also found that vaping seemed to weaken the benefits of staying smoke-free over time. Among people who had stopped smoking for five years or longer, those who used e-cigarettes still had a significantly higher lung cancer risk than people who did not vape.
Among adults aged between 50 and 80 years, the results were particularly alarming. Vaping was linked to a 91 percent higher risk of developing lung cancer and a 92 percent higher risk of dying from the disease.
Scientists say one reason for concern is that e-cigarettes are not chemically harmless. Studies have identified several potentially dangerous substances in vaping products, including cancer-causing chemicals and toxic metals such as lead, nickel, and chromium. Repeated exposure to these substances may contribute to damage inside the lungs over many years.
The researchers caution that the study cannot prove that e-cigarettes directly cause lung cancer. However, the findings strongly suggest that vaping may interfere with some of the major health gains achieved by quitting smoking.
In analyzing these findings, the study highlights an important message for public health. The question may not be whether e-cigarettes are safer than smoking because they probably are for many users. The more important question is whether they are safe enough to replace smoking permanently.
This large study suggests the answer may be no. For smokers who are trying to reduce their risk of lung cancer, completely quitting cigarettes and avoiding long-term e-cigarette use appears to offer the greatest health benefit.
As more long-term data become available, researchers and healthcare providers may need to reconsider how vaping is presented to people seeking a healthier future.
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Source: Nature Medicine study based on South Korea’s National Health Screening Program.
