The latest example comes from a study published in the open-access journal PLOS ONE. The researchers collected human respiratory tissue and exposed it to the nicotine liquid vaporized by electronic cigarettes (e-cigs). Following the experiment the researchers found that exposure to the liquid promoted the production of pro-inflammatory cytokine and made the tissue more susceptible to infection.
Unlike many "studies" of e-cigarettes, this isn't just a survey. The researchers did some actual science; the results are interesting and there is not much fault to find in the experiment itself. Nonetheless, the authors are exaggerating their findings and generally misrepresenting the available evidence.
The media, right on cue as always, reported the results in the worst possible light, leading with headlines like "E-Cigs Could Up Respiratory Infection..." Health reporting in this country sucks tremendously and this issue is no exception, so let's take a closer look at the study and put the data in proper context.
The study begins with a real zinger; I actually snorted when I read it.
"While e-cigarette manufacturers claim that their products are harmless, adverse respiratory effects (e.g., cough, wheezing and pneumonia) have been reported in social media from e-cigarette users . However, the scientific evidence regarding the human health effects of e-cigarettes on the lung is extremely limited.I guarantee you even more positive results have been reported on social media, just visit any number of facebook groups or internet forums dedicated to vaping. The former smokers who populate those venues will happily share their success stories of giving up tobacco. Moreover, their experiences are indicative of a larger result: smokers are switching to e-cigs by the millions because they work. That wouldn't be happening if the devices caused pneumonia.
Moving on to the evidence, the reason we have so little is because e-cigs are relatively new devices. As any researcher knows, good science takes time, and a lot of money. But the data we do have are quite revealing. The first clinical trial to evaluate e-cigs, for example, found that the majority of smokers involved were able to give up traditional cigarettes with few or no side effects. Interestingly, they found that the participants experienced throat and mouth irritation, but that it subsided within a few weeks of the switch. In sum, the research involving real people, and not just their lung tissue, indicates that e-cig use has minimal side effects.
The study authors also repeated Stanton Glantz's gateway to real cigarettes myth, which was debunked literally the same week it first appeared on the internet.
...a notable proportion of adolescents and young adults who had never smoked tobacco cigarettes have used e-cigarettes. About 1.78 million U.S. youth had ever used e-cigarettes as of 2012I would like to point out that "ever used" and "regularly use" are very different things. 38 percent of Americans have tried marijuana, according to Gallup, for instance. That doesn't mean that 38 percent of Americans are pot heads. Yes, many kids have tried e-cigs, but most of them were already smokers, and the majority of e-cig users are adults and former smokers. The gateway argument, then, is in direct contradiction of the data we have.
But let's get to the core of the study, which does seem to provide evidence that e-cigs may be dangerous
In summary, our current study has provided strong data suggesting the deleterious health effects of e-cigarettes on the lung, with a particular focus on airway epithelial inflammation and innate immunity in young people.Well, maybe. We have more data to draw from than the authors suggest throughout the paper. In addition to the clinical evidence, a 2014 review of the chemistry of contaminants in e-cigs concluded "that there is no evidence that vaping produces inhalable exposures to contaminants of the aerosol that would warrant health concerns by the standards that are used to ensure safety of workplaces." We also know that the e-cig vapor contains far fewer organic compounds and particulate metals than cigarette smoke. Comparatively speaking, e-cigs are a dream come true for public health.
We're a decade into the widespread use of e-cigs. And as the data in favor of their safety continues to trickle in, the worst charge that critics can come up with is, "they are not harmless," as Boston University tobacco researcher Michael Siegel has pointed out. E-cigs may turn out to be very harmful, and we definitely should continue to study their use. In the meantime, however, it's going to take more than a handful of lab experiments and hyperbolic headlines to demonstrate that they are really a threat to public health.
EDIT: Two comments on the paper suggest that there may have been some flaws in the experiment.