Yet Another E-Cigarette Study Draws Conclusions that are Unsupported by the Actual Data; This Time, Researchers Claim Vaping Can Cause Car Crashes

A paper recently published online in the journal Drug and Alcohol Dependence concludes that vaping e-liquids that contain high (23.5%) alcohol content cause motor impairment and might promote the progression to dependence upon both nicotine and alcohol. The paper also suggested that vaping an e-cigarette could cause a person to crash their car because of the alcohol intoxication.

(See: Valentine GW, et al. The effects of alcohol-containing e-cigarettes on young adult smokers. Drug and Alcohol Dependence 2015.)

The study procedures were as follows: "Using a randomized, double blind, crossover design, acute changes in subjective drug effects, motor performance and biochemical measures of alcohol and nicotine intake were evaluated after directed and ad lib puffing from two commercially available e-liquids containing nicotine (8 mg/ml), vanilla flavor and either 23.5% (high) or 0.4% (trace) alcohol."

The reported results were as follows: "While no differences in subjective drug effects were observed between alcohol conditions, performance on the Purdue Pegboard Dexterity Test (PPDT) improved under the trace, but not under the 23.5% alcohol condition. Although plasma alcohol levels remained undetectable during testing, urine ethyl glucuronide (EtG), an alcohol metabolite, became measurable in three participants after puffing from the 23.5% alcohol e-cigarette."

The study concluded that alcohol-containing e-cigarettes can cause motor impairment and lead to motor vehicle crashes: "Because alcohol disrupts many psychomotor functions, including those impacting driving performance, dose-dependently with blood alcohol concentrations just above zero, individuals using e-liquids with high alcohol content under ordinary circumstances may be at increased risk of accidents." (reference to Blomberg et al., 2009)

The Rest of the Story

This is an another amazing example of an absurd (and also quite bizarre) extrapolation. The conclusions of the study are completely unsupported by its actual findings.

The most important finding of the study was that vaping e-liquids with very high alcohol content resulted in no detectable alcohol in the blood. To extrapolate from this study - which found no evidence that vaping high-alcohol e-liquids results in any alcohol in the blood - to the conclusion that e-cigarettes may cause car crashes from alcohol intoxication is ridiculous.

The article tries to defend this wild extrapolation by claiming that the referenced study (the Blomberg study) demonstrated that blood alcohol concentrations "just above zero" impair driving performance. But the truth is that the Blomberg study found driving impairment beginning at blood alcohol levels of 0.04-0.05. This misrepresentation of the Blomberg findings will likely deceive anyone reading this article who doesn't have the wherewithal to actually look up the Blomberg study. 

I'm afraid that it is really not rigorous science to obtain study findings showing that vaping high-alcohol liquids results in no detectable alcohol in the blood and then to conclude that e-cigarette use may cause car crashes due to alcohol intoxication. It seems to me that this is the type of thing that, if exposed to the public, could seriously undermine the credibility of public health.

It could also do serious public health damage. If having no alcohol in your blood can cause driving impairment, then what does it matter if you do actually have a little alcohol in your blood? If you are going to become impaired after inhaling the equivalent of 1 sip of alcohol, then why not enjoy yourself and have a whole drink?

Even the study conclusion that vaping impairs motor function in the first place is suspect. This study actually did not find any impairment of motor function in the vaping subjects. Their motor performance was actually better than at baseline. The reason why the authors concluded that there is motor "impairment" is that the observed test scores among the trace alcohol vapers improved more. But this makes little sense because in all the previous studies using the same test (the Purdue Pegboard Dexterity Test), there was no change in the scores of subjects receiving a placebo, while subjects receiving alcohol suffered a significant reduction in their scores. Thus, the results of this study do not provide a solid basis to conclude that vaping a high alcohol e-liquid impairs motor performance.

The worst part of the story is that the article does not address this inconsistency, nor does it even mention any study limitations. It creates the appearance that the investigators had a pre-existing conclusion and were going to reach that conclusion regardless of the actual study findings or the limitations of those findings.

Finally, while the authors declare that there are no conflicts of interest, it appears that the lead author has participated in research funded, in part, by Pfizer, a pharmaceutical company which manufactures products that compete with e-cigarettes in the smoking cessation market. Specifically, he was lead author of a study that received funding from the Yale/Pfizer Imaging Alliance. This creates a conflict of interest that should have been disclosed in the paper. It further muddies the water and creates the appearance of investigator bias.

In addition, another co-author "has served as an expert witness on behalf of Pfizer in lawsuits related to varenicline." This conflict, too, should have been disclosed.

The rest of the story is that this article concludes that vaping high alcohol e-liquids causes motor impairment that could lead to motor vehicle crashes from alcohol intoxication, despite finding that there was no alcohol detectable in the blood of high alcohol e-liquid vapers. This adds to the long line of recent anti-vaping studies which misrepresent or exaggerate their findings in an apparently biased attempt to demonize e-cigarettes. And in this case, at least two of the authors have financial conflicts of interest with Big Pharma - which markets a drug that competes directly with e-cigarettes in the smoking cessation market - creating a perception that these conflicts may have inadvertently influenced the reporting of the study results.