Are Electronic Cigarettes Safer Than Traditional Cigarettes?

August 9, 2017

Cigarettes,_E-Cigarettes_at_Gas_Station_(2)By Gabriel Lutz

Peer Reviewed

Due to the pervasiveness of television and print marketing of electronic cigarettes (e-cigs) in a multitude of flavors and device designs, e-cig use is on the rise in the general population.[1] As physicians, how should we advise our patients looking to quit smoking or those looking for a “healthier” alternative? What does the evidence say about the health risks of e-cigs in first-time smokers?

Generally, e-cigs are composed of a battery and a vaporization chamber that heats a liquid solution containing nicotine, glycerol (or propylene glycol), and artificial flavorings. The heated liquid becomes aerosolized and is inhaled. Unlike traditional cigarettes, no combustion occurs, which means there is no exposure to tars or carbon monoxide with e-cig use. Due to the relative nascency of e-cigs, production of vaporizing devices as well as the nicotine-containing liquids themselves has not yet been standardized. Until standardization occurs, true comparisons against traditional tobacco cigarettes will be challenging. Despite this, initial analyses from small randomized clinical trials have shown reduced concentrations of formaldehyde and acetaldehyde (both carcinogens) in e-cigs compared to traditional cigarettes. However, it’s also been observed that several commonly sold nicotine-containing liquids contain chemicals not listed on the product packaging,[2,3,4] raising serious safety concerns. Furthermore, when propylene glycol present in nicotine liquids is heated high enough, the carcinogen propylene oxide may form.

Thus far, studies in mice have demonstrated that initial short-term exposure to aerosolized nicotine vapors resulted in increased pulmonary endothelial inflammation, oxidative stress,[5,6,7,8] and an increased susceptibility to bacterial pneumonia[5] and influenza A,[9] compared with mice not exposed to aerosolized nicotine. Additionally, exposure to nicotine vapors during early life in mice led to decreased lung growth compared to mice raised in ambient air.[10]

Unfortunately, there aren’t yet sufficient data to answer the question most germane to everyday clinical practice: whether smoking of e-cigs is truly safe relative to traditional cigarettes, and if switching from traditional to electronic cigarettes can aid smoking cessation. Studies in humans have been small and have generally not demonstrated a statistically significant difference in rates of smoking cessation between individuals receiving nicotine patches, nicotine e-cigs, or non-nicotine e-cigs. However, studies of nicotine-replacement therapy have shown that, aside from its addictive potential and the unpleasant neurological and gastrointestinal side effects, long-term exposure to nicotine alone is not associated with an increased rate of myocardial infarction or cancer.[11] That is not to say that e-cig use is “safe” by any means. In high enough doses, concentrated liquid nicotine has proven to be fatal to both adults [12] and children,[13] and since its production is not yet standardized, use of these products needs to be done with considerable care.

Ultimately, what is the best recommendation to give patients seeking to quit smoking? First and foremost, active support in the form of individual counseling as well as encouragement from a patient’s social network should be present, because the presence of support has been associated with increased quitting success compared to simply purchasing nicotine replacement therapy over the counter.[14] If nicotine replacement therapy has been attempted unsuccessfully, first-line medications such as varenicline or bupropion should be tried. If these too fail, it is up to a clinician’s judgment whether or not to recommend a transition to e-cigs. Though e-cig vapor is widely believed to be less damaging than smoke from traditional cigarettes,[15,16] e-cigs are still not an FDA-approved smoking cessation aid, and the United States Preventive Services Task Force lists the evidence for therapeutic use of e-cigs as inconclusive.[17] As physicians, we should encourage and support patients’ desire to quit smoking and work together with them to find a viable smoking cessation modality. Currently, e-cigs are regulated by the FDA,18 and in New York City the use of e-cigs is banned by law in all places where traditional cigarettes are banned,[19] and therefore in these locations (nursing homes, hospitals), only current nicotine replacement therapies can be used.

Commentary by Dr. Kelly Kyanko

In theory, e-cigarettes are nicotine replacement therapy except with better marketing. However, at present there is insufficient evidence to indicate if they are truly safer than conventional tobacco cigarettes and if they are effective as a smoking cessation aid. Research is rapidly emerging in this field, and it is likely that we will have more evidence to guide discussions with our patients in the near future. In my practice, in line with USPSTF guidance I recommend conventional NRT for smoking cessation, which we know is effective and safe. However, if patients are already using e-cigarettes and have found success in cutting back or quitting smoking, I do not discourage them from continuing use.

Gabriel Lutz is a 3rd year medical student at NYU Langone School of Medicine

Peer reviewed by Kelly Kyanko, MD, Assistant Professor departments of population health and medicine, NYU Langone Health

Image courtesy of Wikimedia Commons


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