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Review
. 2024 Jun 28;63(6):2301494.
doi: 10.1183/13993003.01494-2023. Print 2024 Jun.

The paradox of the safer cigarette: understanding the pulmonary effects of electronic cigarettes

Kassandra Allbright  1 , John Villandre  1 , Laura E Crotty Alexander  2   3 , Michael Zhang  1 , Kambez H Benam  1   4   5 , John Evankovich  1 , Melanie Königshoff  1 , Divay Chandra  6
Affiliations
Review

The paradox of the safer cigarette: understanding the pulmonary effects of electronic cigarettes

Kassandra Allbright et al. Eur Respir J. .

Abstract

Electronic cigarette (e-cigarette) use continues to rise globally. E-cigarettes have been presented as safer alternatives to combustion cigarettes that can mitigate the harm associated with tobacco products; however, the degree to which e-cigarette use itself can lead to morbidity and mortality is not fully defined. Herein we describe how e-cigarettes function; discuss the current knowledge of the effects of e-cigarette aerosol on lung cell cytotoxicity, inflammation, antipathogen immune response, mucociliary clearance, oxidative stress, DNA damage, carcinogenesis, matrix remodelling and airway hyperresponsiveness; and summarise the impact on lung diseases, including COPD, respiratory infection, lung cancer and asthma. We highlight how the inclusion of nicotine or flavouring compounds in e-liquids can impact lung toxicity. Finally, we consider the paradox of the safer cigarette: the toxicities of e-cigarettes that can mitigate their potential to serve as a harm reduction tool in the fight against traditional cigarettes, and we summarise the research needed in this underinvestigated area.

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Conflict of interest statement

Conflict of interest: K. Allbright reports grants from Burroughs Wellcome Fund and T32 (5T32HL007563-35), outside the submitted work. L.E. Crotty Alexander reports grants from NIH NHLBI R01, NIH NHLBI K24 and VA Merit Award, advisory board participation with Regeneron, and leadership roles with CHEST and ALA San Diego, outside the submitted work. M. Zhang reports support for the present article from Regeneron Pharmaceuticals. K.H. Benam has received grants from the US Food and Drug Administration, US National Institutes of Health, US Department of Defense and the Gordon and Betty Moore Foundation, royalties from Emulate Inc., consulting fees from Pneumax LLC, has received invited speaker honorarium from Colorado State University, has multiple pending and issued patent applications, has non-significant personal investments in a number of publicly traded companies, and is the founder of Pneumax LLC. The remaining authors have no potential conflicts of interest to disclose.

Figures

FIGURE 1
FIGURE 1
Components of a typical electronic cigarette.
FIGURE 2
FIGURE 2
Generations of electronic cigarettes as defined by the Centers for Disease Control and Prevention.
FIGURE 3
FIGURE 3
Summary of the potential toxicities of e-cigarette aerosol on the lungs. IL: interleukin; CXCL: chemokine (C-X-C motif) ligand; IFN: interferon; TNF: tumour necrosis factor; MIP: macrophage inflammatory protein; 8-oxo-dG: 8-oxo-2’-deoxyguanosine; H2O2: hydrogen peroxide; HO: haem oxygenase; GCLM: glutamate-cysteine ligase modifier; GCLC: glutamate-cysteine ligase catalytic subunit; GPX: glutathione peroxidase; MCP: monocyte chemoattractant protein; AT2: alveolar type 2 cell.
FIGURE 4
FIGURE 4
Phenomena that will probably erode some of the potential gains from the lower puff-for-puff toxicity of e-cigarette aerosol compared with combustion cigarette smoke. The proportions of various subgroups in this figure, i.e. combustion cigarette smokers, quitters, e-cigarette users, dual users, etc. are hypothetical and for visual representation only.
FIGURE 5
FIGURE 5
The paradox of the safer cigarette.
See this image and copyright information in PMC

References

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