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E-cigarettes increase airway inflammation.... compared to what?

Posted by DrFarsalinos on 26 Sep 2014 at 23:07 GMT

For the shake of discussion, i will disagree with the previous comment by Bernd Mayer and i will accept that e-cigarettes increase inflammation..... compared to what???

E-cigarette use is overwhelmingly used by smokers, as a partial or complete substitute. To serve the public health in general, and each individual smoker separately, it is our ethical duty to inform smokers what would change in their health status if they switch from tobacco to e-cigarette use.
This study provides absolutely no comparison with tobacco cigarette. Additionally, it provides no comparison with any other smoking cessation tool (bupropion, varenicline). I wonder, what would happen if you expose these cells to any of these pharmaceutical products for 2 days?
Of course, e-cigarettes are used through inhalation of its vapor, not in the way the authors tested the liquids. That is why it would be realistic to:
1. Use an e-cigarette device and produce vapor; use the vapor extract on the cells
2. Make tobacco cigarette smoke extract and use this as comparison.
For the latter, the most probable reason for not doing it is simple: the tobacco smoke extract would have been so cytotoxic that only few cells would have survive [1, 2]. Thus, there would be no elevation in IL-6, because you need viable cells to produce it.

Asthma, a predominantly inflammatory disease of the airways, is adversely affected by smoking. Although there is a lot of speculation about the adverse effects of e-cigarettes use on asthmatic patients, there is only one study published, which has shown the exact opposite: asthmatics who switch from tobacco to e-cigarette use experience significant improvements in respiratory function (both subjective and objective) [3].

When results of laboratory experiments contradict evidence from human studies, one should be concerned about the reliability of the laboratory experiments and their applicability to human effects.


1. Romagna G, Allifranchini E, Bocchietto E, Todeschi S, Esposito M, Farsalinos KE. Cytotoxicity evaluation of electronic cigarette vapor extract on cultured mammalian fibroblasts (ClearStream-LIFE): comparison with tobacco cigarette smoke extract. Inhal Toxicol. 2013 May;25(6):354-61.

2. Farsalinos KE, Romagna G, Allifranchini E, Ripamonti E, Bocchietto E, Todeschi S, Tsiapras D, Kyrzopoulos S, Voudris V. Comparison of the cytotoxic potential of cigarette smoke and electronic cigarette vapour extract on cultured myocardial cells. Int J Environ Res Public Health. 2013 Oct 16;10(10):5146-62.

3. Polosa R, Morjaria J, Caponnetto P, Caruso M, Strano S, Battaglia E, Russo C. Effect of smoking abstinence and reduction in asthmatic smokers switching to electronic cigarettes: evidence for harm reversal. Int J Environ Res Public Health. 2014 May 8;11(5):4965-77.

Competing interests declared: I have 21 publications in peer-reveiwed journals about e-cigarettes and 2 more studies presented in medical conferences
For 2 of them (unpublished yet), funds provided to my institution from e-cigarette companies were used
For 2 of them, institutes unrelated to me received funding from e-cigarette companies
For 1 of them, funding from a non-profit association was provided
For 1 of them, funding through a public internet crowdfunding campaign was provided
For 17 of them, no funding support was provided by anyone