November 20, 2017

Stanton A. Glantz, PhD

Five myths about e-cigs and some of the evidence that they are, well, myths

The latest e-cig love fest at the 2017 E-cig Summit in England has been bouncing around the internet, so I thought it would be worth summarizing some of the evidence debunking common e-cig myths.  The list of citations is nowhere near exhaustive, but illustrates why these myths are myths.

Myth 1: There is no gateway effect. 

A recent meta-analysis shows 100% consistent evidence that never cigarette smoking youth who begin nicotine use with e-cigarettes are significantly more likely to progress to cigarette smoking than youth who do not use e-cigarettes. There have been several additional longitudinal studies published that have shown the same thing since this meta-analysis was published, including one from England.

There are also consistent data showing that e-cigarettes attract youth at low risk of beginning tobacco use with cigarettes and expanding the overall nicotine use market.

Association Between Initial Use of e-Cigarettes and Subsequent Cigarette Smoking Among Adolescents and Young Adults: A Systematic Review and Meta-analysis. Soneji S, Barrington-Trimis JL, Wills TA, Leventhal AM, Unger JB, Gibson LA, Yang J, Primack BA, Andrews JA, Miech RA, Spindle TR, Dick DM, Eissenberg T, Hornik RC, Dang R, Sargent JD. JAMA Pediatr. 2017 Aug 1;171(8):788-797. doi: 10.1001/jamapediatrics.2017.1488

Risk factors for exclusive e-cigarette use and dual e-cigarette use and tobacco use in adolescents. Wills TA, Knight R, Williams RJ, Pagano I, Sargent JD. Pediatrics. 2015;135(1):e43pmid:25511118

Psychosocial factors associated with adolescent electronic cigarette and cigarette use. Barrington-Trimis JL, Berhane K, Unger JB, et al. Pediatrics. 2015;136(2):308–317pmid:26216326
E-cigarettes and National Adolescent Cigarette Use: 2004-2014. Dutra LM, Glantz SA. Pediatrics. 2017 Feb;139(2). pii: e20162450. doi: 10.1542/peds.2016-2450

Myth 2: E-cigarettes increase smoking cessation.

A meta-analysis showed that, considering all available data at the time, e-cigarettes are associated with depressed cessation. While some of the studies published since then show increased smoking cessation among e-cigarette users, the overall pattern remains depressed cessation.

E-cigarettes and smoking cessation in real-world and clinical settings: a systematic review and meta-analysis. Kalkhoran S, Glantz SA. Lancet Respir Med. 2016 Feb;4(2):116-28. doi: 10.1016/S2213-2600(15)00521-4. Epub 2016 Jan 14.

Myth 3: E-cigarettes are 95% safer than conventional cigarettes.

This assumption is based on the paper by Nutt et al that represented the opinions of a few  ‘experts” without citing any specific supporting evidence. The process by which this paper was prepared has been criticized for conflicts of interest among some of the authors. More important, since then there has been a substantial literature published indicating important cardiovascular and pulmonary risks associated with e-cigarette use. Cardiovascular and pulmonary disease kill about 2/3 of smokers. 
E-cigarettes: Public Health England's evidence-based confusion. [No authors listed] Lancet. 2015 Aug 29;386(9996):829. doi: 10.1016/S0140-6736(15)00042-2.

Pulmonary toxicity of e-cigarettes. Chun L, Moazed F, Calfee CS, Matthay MA, Gotts JE. American Journal of Physiology - Lung Cellular and Molecular Physiology Published 1 August 2017 Vol. 313 no. 2, L193-L206 DOI: 10.1152/ajplung.00071.2017

Increased Cardiac Sympathetic Activity and Oxidative Stress in Habitual Electronic Cigarette Users: Implications for Cardiovascular Risk. Moheimani RS, Bhetraratana M, Yin F, et al. JAMA Cardiol. 2017;2(3):278-284. doi:10.1001/jamacardio.2016.5303

Cardiovascular Perspective of the Promises and Perils of E-Cigarettes. Bhatnagar A. Circ Res. 2016 Jun 10;118(12):1872-5. doi: 10.1161/CIRCRESAHA.116.308723.

Myth 4: Even if smokers don’t quit when they use e-cigarettes they smoke fewer cigarettes and the health risks go down substantially in smokers that reduce consumption.

The claim that smokers who use e-cigarettes is also not consistently supported by the evidence.  More important, even low levels of smoking convey substantial risks, especially for cardiovascular disease, where smoking even a few cigarettes is as dangerous as smoking 20 cigarettes a day.  

Health consequences of reduced daily cigarette consumption. Tverdal A, Bjartveit K. 
Tob Control. 2006 Dec;15(6):472-80..

Health consequences of smoking 1-4 cigarettes per day. Bjartveit K, Tverdal A. Tob Control. 2005 Oct;14(5):315-20. 

Health effects of light and intermittent smoking: a review. Schane RE, Ling PM, Glantz SA. Circulation. 2010 Apr 6;121(13):1518-22. doi: 10.1161/CIRCULATIONAHA.109.904235.
Myth 5:  Nicotine is addictive, but it doesn’t pose any other substantial risks.
Nicotine is a reproductive toxin.  While not a carcinogen, nicotine plays an important role in promoting tumor progression by promoting cell proliferation and inhibiting normal cell death by activating nicotinic acetylcholine receptors and β adrenergic receptors.  Nicotine also promotes the angiogenesis  needed to supply blood to growing tumors.  Nicotine’s effects on nicotinic acetylcholine receptors also accelerates atherosclerosis.It also aggravates lung disease and other diseases.
50 Years of Progress: A Report of the Surgeon General, 2014.  Chapter 5: Nicotine
Nicotine-mediated cell proliferation and tumor progression in smoking-related cancers. Schaal C, Chellappan SP.  Mol Cancer Res 2014;12:14-23.
Recent updates on electronic aerosol and inhaled nicotine effect on peridontal and pulmonary tissues. Javed F, Kellasarian SV, Sundar IK et al.   Oral Diseases 2017; epub Feb 6.
The role of nicotine in the pathogenesis of atherosclerosis. Lee J, Cooke JP.  Atherosclerosis 2011;215:281-3.

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