Vaping and Lung Health: Weighing the Evidence on Risks, Benefits, and Unanswered Questions

The relationship between vaping and respiratory health remains a topic of ongoing debate and research. While some studies suggest that e-cigarette use may produce harmful chemicals that could affect lung function, others indicate no significant short- or medium-term impact on respiratory health. More importantly others report a significant benefit when switching from smoking to vaping. Findings vary depending on factors like vaping frequency, product type, and user history (such as former smokers versus non-smokers).

A 2024 study presented at the European Respiratory Society (ERS) Congress in Vienna reported that young people who vape have reduced exercise capacity compared to non-vapers, with performance levels similar to smokers. Led by Dr. Azmy Faisal of Manchester Metropolitan University, the study involved 60 participants in their 20s—20 vapers, 20 smokers, and 20 non-users.

Vapers and smokers both showed lower peak exercise capacity and oxygen consumption than non-users. They also experienced greater breathlessness, muscle fatigue, and impaired blood vessel function. Researchers concluded that long-term vaping may harm physical fitness, with effects comparable to smoking. However, it is unclear whether the 20 vaping participants were previous smokers, in which case their symptoms could have been brought on by their previous smoking not the vaping.

The struggle to separate the effects of vaping and smoking

In fact, in most cases the potential respiratory risks of electronic cigarettes (ECs) remain uncertain due to the difficulty of separating their effects from those of conventional smoking. To address this, a systematic review was conducted to evaluate respiratory health outcomes specifically among individuals who have never smoked. The review followed a comprehensive approach, beginning with a narrative assessment and critical appraisal of existing literature. It then systematically examined prospective studies investigating the relationship between EC use and respiratory effects in never-smokers.

Evidence also indicates that switching from smoking to vaping may offer respiratory benefits.

The review assessed bias risk using the Joanna Briggs Institute tool and identified ten eligible studies. These studies explored various respiratory outcomes, including self-reported respiratory conditions, symptoms such as coughing and wheezing, and lung function. Among the ten studies, eight focused on adults, while three included youth participants, with some overlap.

The findings revealed that seven of the ten studies did not establish any significant link between EC use and adverse respiratory outcomes in never-smokers. However, evidence regarding symptoms like coughing and wheezing varied depending on the analytical model used. While no strong association was found between EC use and severe respiratory conditions, some studies suggested a potential link to mild respiratory symptoms.

Reviews of reliable studies find no signs of significant lung damage from vaping

Meanwhile, a review co-authored by award winning researcher and respiratory physician Dr. Riccardo Polosa, took into account that another challenging aspect of studying the effects of vaping is the different usage patterns. Some users may vape while still smoking (dual use), after quitting smoking (exclusive use), or without ever smoking cigarettes (naïve use). This review aimed to analyze how these different patterns affect lung health in adults.

The research team searched major scientific databases for studies that measured lung function through tests like spirometry, breath analysis, and clinical outcomes. They included 12 systematic reviews and assessed their quality using established guidelines.

The results showed no significant impact on lung function for any type of e-cigarette use in the short or medium term. However, the study identified common problems in the research, such as bias in reporting, the inclusion of people who used e-cigarettes infrequently, and as mentioned previously, the difficulty of separating the effects of e-cigarettes from participants’ smoking history. Overall, the current evidence does not show major changes in lung health due to e-cigarette use, but better-quality studies are needed for clearer conclusions.

While the general consensus seems to be that the current research on the relationship between vaping and respiratory health remains somehat inconclusive, with some studies suggest potential harm, most report no significant negative impact, particularly among exclusive vapers. More importantly, evidence also indicates that switching from smoking to vaping may offer respiratory benefits. However, inconsistencies in study methods, differences in user behavior, and the challenge of separating vaping effects from prior smoking make it difficult to draw definitive conclusions. Further high-quality, long-term research is needed to fully understand the potential risks or benefits of e-cigarette use, especially in individuals who have never smoked conventional cigarettes.