No, e-cigarettes are not harmless: new research led by National Jewish Health indicates that these cigarettes are no less risky than the “classic” ones. In fact, the study shows that just a few days of exposure to the vapor from electronic cigarettes can damage the most delicate lung tissues, making them more vulnerable to viral infections.
It is not the first research that reports significant risks of e-cigarettes: just to cite the most recent example, a study conducted on lung tissue, published last April in Analytical and Bioanalytical Chemistryfound in the same tissues, after a short exposure, nickel, lead, copper, aluminum, tin, arsenic and traces of mercury, with localized accumulations and an irregular distribution.
Now researchers have analyzed human lung epithelial and endothelial cells, as well as samples of human lung tissue taken from the distal portion of the lung, the deepest and most fragile region, where oxygen passes into the bloodstream.
Specifically, in preclinical models, tissues were exposed to e-cigarette vapor alone, while in another scenario, vapor exposure was followed by infection with a respiratory virus.
The results showed that, within 24 hours, steam compromised the protective barrier of the distal lung, triggered cellular stress, altered internal mechanisms for removing damaged cellular components, slowed cell growth and repair, and increased cell mortality.
Significantly, it also emerged that signs of lung stress persisted even 10 days after the end of an exposure period that lasted just five days. The researchers found long-lasting alterations in barrier function, tissue remodeling, and Th1 immunity, a component of the immune system critical to fighting viral infections.
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Among other things, the researchers observed that repeated exposure could contribute to the development of chronic lung diseases, perpetuating cellular damage and hindering normal repair processes.
The last but not the leastprior exposure to vapor increased the viral load of SARS-CoV-2, the virus responsible for Covid-19, and suppressed the expression of several antiviral genes following infection.
Our findings suggest that even short-term exposure to e-cigarette vapor can cause damage in the deepest and most delicate regions of the lung – explains Irina Petrache, who led the research – Importantly, some effects persisted even after cessation of exposure, altering the immune response to a subsequent viral infection
The data are not definitive, because they will have to be verified on humans, but they are still highly indicative, highlighting biological mechanisms that could explain why the use of e-cigarettes has been associated with lung lesions and greater susceptibility to respiratory infections.
The work was published on JCI Insights.
Sources: National Jewish Health / JCI Insight
