A recent study by Scott and colleagues attempted to investigate the potential effects of vaping on the lungs by studying the effects of vapourized components on human alveolar macrophages.
Electronic cigarettes (e-cigarettes) are becoming a popular activity among both traditional cigarette smokers and ex-smokers. Using e-cigarettes is also called vaping, as the individual inhales vapors. The popularity of vaping largely stems from the belief that e-cigarettes are a safer alternative to traditional cigarettes and are associated with fewer health risks. Although this may be true, e-cigarettes may have their own specific health risks that have not yet been identified and fully investigated.
There are currently very few long-term studies that have examined the effects of vaping on our overall health. Moreover, as e-cigarettes increase in their complexity and variety, the effects they have on users will become more uncertain and will warrant careful investigation.
Previous study found that unvapourized fluid in e-cigarettes caused lung damage
In a previous study, scientists have shown that animals exposed to the unvapourized fluid found in e-cigarettes, called e-cigarette liquid (ECL), resulted in increased secretion of inflammatory markers and caused airway and lung damage. They did not, however, investigate whether vaporized ECL had a similar effect on the animals. It is important to realize that the process of vaping itself can induce changes in the chemical make-up of the ECL. Therefore, vapourized ECL must be studied in addition to unvapourized ECL to fully determine the potential effects of e-cigarettes on our health.
How do e-cigarettes affect immune cells on the lungs?
In a more recent study by Scott and colleagues, researchers investigated the effects of vaping on the lungs’ immune cells. Specifically, they looked at how e-cigarette vapour condensate (ECVC) on alveolar macrophages found in the lungs. Macrophages are large cells found in the body that play a vital role in the immune system. Alveolar refers to the lung.
Scott and colleagues exposed alveolar macrophages to ECVC with or without nicotine for 24-hours and used various experimental techniques to assess the viability of alveolar macrophages, pro-inflammatory effect, and function. Their results were published in the journal Thorax.
The results demonstrated that ECVC was more toxic to the alveolar macrophages compared to ECL. They also found that ECVC with nicotine was considerably more toxic than ECVC alone, suggesting that the cytotoxic effects are at least partly because of nicotine. Furthermore, they showed that ECVC exposure, with or without nicotine, significantly increased cell death in comparison to untreated alveolar macrophages.
When they included nicotine in the ECVC treatment, they found the highest amount of cell death, further suggesting that nicotine worsens the effects of ECVC on alveolar macrophages. It was also found that the 24-hour exposure, with or without nicotine, resulted in a five-fold increase in macrophage reactive oxygen species (ROS) production, compared to untreated controls. ROS are unstable molecules that have been associated with cell damage and death in many diseases. In addition to this, researchers found that alveolar macrophages exposed to ECVC, with or without nicotine, secreted higher levels of pro-inflammatory components and had an impaired ability to engulf bacteria.
Vaping with nicotine exacerbates the toxic effects of e-cigarette liquid on lung cells
In conclusion, the authors have demonstrated that the process of vaping does, in fact, exacerbate the cytotoxic effects of ECL. Furthermore, they show that ECVC has significant negative effects on human alveolar macrophages, which are exacerbated by nicotine.
It is unclear whether there are separate nicotine dependent and independent mechanisms for these effects, but this could be investigated in the future. It is obvious, however, that ECVC with nicotine has a considerably more profound effect on alveolar macrophages than ECVC alone.
Overall, the current study highlights that although e-cigarettes are considered a safer alternative to traditional cigarettes, there are still negative effects of vaping on the lungs. More thorough and careful studies are necessary to more comprehensively study the effects of all the different e-cigarette components and chemicals on our health.
Written by Haisam Shah, BSc
- Scott, A., Lugg, S. T., Aldridge, K., Lewis, K. E., Bowden, A., Mahida, R. Y., … &Sapey, E. (2018). Pro-inflammatory effects of e-cigarette vapour condensate on human alveolar macrophages. Thorax, thoraxjnl-2018.
- Garcia-Arcos, I., Geraghty, P., Baumlin, N., Campos, M., Dabo, A. J., Jundi, B., … &Foronjy, R. (2016). Chronic electronic cigarette exposure in mice induces features of COPD in a nicotine-dependent manner. Thorax, thoraxjnl-2015.
- Lerner, C. A., Sundar, I. K., Yao, H., Gerloff, J., Ossip, D. J., McIntosh, S., … & Rahman, I. (2015). Vapors produced by electronic cigarettes and e-juices with flavorings induce toxicity, oxidative stress, and inflammatory response in lung epithelial cells and in mouse lung. PloS one, 10(2), e0116732.