I’ve made no secret of my opinion of Jenny McCarthy. To put it mildly, I don’t think that much of her, particularly her flaming stupid when it comes to her promotion of dangerous antivaccine nonsense. To her, vaccines are chock full of “toxins” and all sorts of evil humors that will turn your child autistic in a heartbeat if you let those horrible pediatricians inject them “directly into the bloodstream” and in general “steal” your “real” child away from you the way she thinks vaccines “stole” her son Evan away from her. Indeed, among other “achievements,” she’s written multiple books about autism in which vaccines feature prominently as a cause, led a march on Washington to “green our vaccines” and has been the president of the antivaccine group Generation Rescue for the last few years. None of this stopped ABC from foolishly hiring her to join the regular cast on The View beginning in a few short weeks.
Because I occasionally check on what Jenny McCarthy is up to, I noticed a couple of weeks ago that she had been hired to be a celebrity spokesperson for blu™ e-cigarettes. Curious, I checked out this video of her hawking the blu™ Starter Pack:
Particularly odd to me is how the ad has Jenny McCarthy hawking blu™ e-cigarettes as a “sexy” way to smoke. She points out dramatically that, now that she is single, being a smoker is a big problem because, apparently, smoking itself is a big turnoff to a lot of men and she hates interrupting dates to have to go outside to catch a smoke. If you believe the commercial, blu™ e-cigarettes have completely revitalized Jenny McCarthy’s love life, apparently in the wake of her breakup with Jim Carrey a couple of years ago. Like Matt Carey, I also could not escape the irony of the woman who rails against “toxins” in vaccines and described her struggles trying to stop smoking when she was pregnant now shilling for a device designed to be used to inhale a toxic substance (nicotine) into one’s lungs. On the other hand, she has in the past raved about how she absolutely “loves” Botox; so maybe it’s not so difficult to understand.
Jenny McCarthy’s decision to shill for an e-cigarette company “inspired” me to think that now is a good time to do a post on the evidence base behind e-cigarettes. In particular, I thought it a good time because I have recently been bombarded with huge amounts of e-cigarette spam e-mail, and I’ve also noticed that a certain organization that represents itself as defending the public against health scares by countering them with science, namely the American Council on Science and Health (ACSH) is very high on e-cigarettes, even going so far as to praise Jenny McCarthy for being on the right side of science for a change, a post that made me want to gag. Unfortunately, I couldn’t given that the awesome computer that is Orac is a Plexiglass box of blinking colored lights. A quick search of the ACSH website for e-cigarettes reveals hundreds of posts about them, all uniformly either praising e-cigarettes as the greatest thing since sliced bread for “safer smoking,” harm reduction, and an aid to smoking cessation or chastising anyone that has anything bad to say about them or any government entity that seeks to ban or tightly regulate them. Indeed, Gilbert Ross, MD, the executive and medical director at the ACSH, has even written posts for Forbes in which he accuses regulators who would restrict or ban e-cigarettes as being out to kill American smokers, a message echoed on the ACSH’s own website, in which apparently European Union regulators share the same homicidal urges towards European smokers that American regulators apparently exhibit towards theirs.
I do so love it when an advocate’s rhetoric accuses his enemies of wanting to kill innocent people. Nothing starts my skeptical antennae a’twitchin’ faster than that. I can’t help but wonder if that advocate is laying down heapin’ helpin’s of grade-A BS. However, I don’t know for sure that that’s the case; it might not be. Maybe ACSH is right and e-cigarettes are the most wonderful invention for public health since vaccines. On e-cigarettes, I have been and remain agnostic. After all, it’s not implausible to speculate that e-cigarettes might be a useful strategy to assist smokers in quitting as just another nicotine delivery system, nor is it implausible that they could be a safer means of “smoking” than cigarettes. On the other hand, let’s face it. E-cigarettes are, without a doubt, drug delivery devices designed to administer nicotine in a vapor, virtually identical in concept to nicotine inhalers already used for smoking cessation, but smaller and looking very much like cigarettes, making them more convenient and socially acceptable for use outside of the home. Yet, as of this writing nicotine inhalers are regulated by the FDA as a drug/device combination, while e-cigarettes are not. As a result, I view e-cigarettes as being in the same category as supplements. This leads to the only question that matters to me in a health issue like this: What does the science show? The disappointing answer: Not a lot one way or the other regarding the two key claims about e-cigarettes: (1) that they’re a safe way to “smoke” and (2) that they are a highly effective smoking cessation aid.
E-cigarette facts and history
The effects of tobacco smoking result in enormous morbidity and mortality, through the various cancers caused by smoking, most prominently lung cancer, as well as chronic obstructive pulmonary disease (COPD), and cardiovascular disease resulting in heart attacks, limb loss, and strokes. Consequently, reducing harm from tobacco is a major public health challenge, and smoking cessation would result in an enormous decline in premature death and disability. Indeed, if smoking prevalence were reduced to zero, lung cancer, heart disease, an COPD prevalence would plummet. Various nicotine-delivery systems, such as nicotine patches and nicotine inhalers, have proven to be useful aids to smoking cessation.
E-cigarettes are the most common variant of a class of medical devices known as electronic nicotine delivery systems (ENDS), whose purpose is to vaporize nicotine, along with other substances used to affect the vapor consistency and flavor, and deliver it to the lungs of the user. Indeed, quite a bit of effort goes into making the vapor look like smoke, as can be seen in the video above. Each device typically consists of a tube made of plastic or other material in which there are housed a rechargeable battery, electronic controls, and an electronic vaporization system. Cartridges containing the liquid mixture to be vaporized are attached to the tube, and puffing on the e-cigarette results in the production of vapor, which is inhaled. Frequently, there is a light at the end of the tube that lights up when a puff is taken to simulate the lit end of a cigarette. One notes from Jenny McCarthy’s commercial that in the case of blu™ e-cigarettes this light is blue, for reasons that escape me.
The first generation of e-cigarettes as we know them today was developed by a Chinese pharmacist, Hon Lik, in 2003 and patented soon thereafter. They were first introduced into the Chinese market in 2004 and reached the international market by 2006. It didn’t take long for a variety of manufacturers to start making them and promoting them as a “healthy alternative” to smoking or as an aid to smoking cessation. In a relatively short period of times, selling e-cigarettes has become big business; it’s been estimated that e-cigarette sales could reach $1.7 billion this year. That’s still a fraction of the $80 billion a year tobacco industry, but it’s a rapidly growing one. Moreover, many e-cigarette companies are owned by tobacco companies, something the ACSH applauds; for example, blu is owned by Lorillard.
According to e-cigarette manufacturers, the vapor inhaled from e-cigarettes does not contain tar or many of the toxic chemicals found in real cigarette smoke. The chemical mixture vaporized is typically composed of nicotine, propylene glycol, and other chemicals. Not all e-cigarettes use propylene glycol as the vaporizing agent (for example, blu e-cigarettes use vegetable glycerin instead), although many do, along with flavors designed to make the vapor more pleasant and attractive, such as menthol, vanilla, cherry, coffee bean, chocolate, apple, and, yes, various kinds of tobacco. This proliferation of flavors has led to concerns that e-cigarettes are attractive to children and could facilitate getting them hooked on nicotine or even serve as a “gateway” to real smoking.
Through a quirk of a ruling based on the 2009 Family Smoking Prevention and Tobacco Control Act,, as long as manufacturers do not make health claims for them the FDA cannot regulate e-cigarettes as drug/device combinations, even though that’s what they clearly are. This is why you don’t see ads touting e-cigarettes as a smoking cessation aid, but rather as a “healthy alternative” to smoking. Here’s what happened. Between 2008 and 2010, the FDA determined that e-cigarettes were unapproved drug/device combinations, but Sottera, Inc., an e-cigarette manufacturer challenged the FDA in court, and the U.S. Court of Appeals for the D. C. Circuit ruled in Sottera, Inc. v. Food & Drug Administration in 2010 that a jurisdictional line should be drawn between “tobacco products” and “drugs,” “devices,” and combination products. The court further ruled that e-cigarettes and other products made or derived from tobacco can be regulated as “tobacco products” under the act and are not drug/device combinations unless they are marketed for therapeutic purposes. For reasons that are unclear to me, the FDA declined to challenge the ruling, but retains the power under the Tobacco Control Act to add categories to the tobacco products it regulates after going through procedural steps that include a public comment process. As a result, the FDA plans to propose draft regulations for e-cigarettes this fall and put them out for public comment. Until such a time as the FDA finalizes regulations, however, e-cigarettes are unregulated by the FDA, although some states have banned them in public places, much as cigarette smoking is banned in public places in many states. This quirk of U.S. law has been the proverbial camel’s nose in the tent that opened the way for the currently booming e-cigarette business.
Are e-cigarettes safer than cigarettes?
Since the main claim being used to sell e-cigarettes right now is that they are safer than tobacco-containing cigarettes, that’s the first claim that needs to be examined. If you look at e-cigarette advertising, it’s hard not to feel a sense of déjà vu with respect to past tobacco company ads, complete with appeals to “freedom” (Jenny McCarthy’s ad uses that, among other common advertising ploys, such as the implication that you’ll have more sex if you use this product), celebrity endorsements (McCarthy again), and appeals to sophistication, freedom, equality and individualism. All of this is coupled with, of course, appeals to health, such as this ad for South Beach Smoke:
Indeed, e-cigarette advertising has been characterized as the “Wild, Wild West,” something out of Mad Men, and the “next great frontier” for ad agencies. It’s not hard to see why. I mean, holy crap. E-cigarette ads are just as blatant as anything I’ve seen in ads from the 1960s and earlier for cigarettes. I wonder how long it will be before they start showing pictures of doctors to testify how safe they are, the way they did in the 1940s.
As I said earlier, it is not implausible that “vaping” (as inhaling e-cigarette vapor is commonly called) might be safer than tobacco cigarettes. After all, they don’t contain the tar and combustion products that cigarette smoke does, although most of them do contain the nicotine. There are nicotine-free e-cigarette cartridges for those who want the experience of smoking but not the nicotine. To me that seems like drinking decaffeinated coffee, something I’ve never been able to understand, but maybe that’s just me. I needs me my caffeine, I’m afraid. Be that as it may, there really is a dearth of evidence one way or the other regarding the safety of e-cigarettes. The evidence that is out there, from my perusal of it, is of almost completely uniformly low quality. Particularly lacking are long-term studies of e-cigarette use, obviously because they’ve only been on the market for less than a decade and only skyrocketed in popularity beginning around five years ago. For instance, Odum et al pointed out that
Most e-cigarette data on safety and efficacy are derived from the surveys of current or past e-cigarette users.14-18 The surveys have reported successful reduction in smoking and benign side effects, such as dry mouth, throat irritation, dry cough, vertigo, headache, and nausea (Tables 1). Most survey participants were male and from the Unites States, Europe, and Canada. Respondents were typically recruited by posting links on e-cigarette or smoking cessation Web sites and/or sending e-mails with survey links to consumers of ecigarettes. One survey18 recruited subjects by handing out questionnaires at an e-cigarette enthusiast meeting. Many of these surveys14,15,17,18 provided only descriptive analyses to understand the usage patterns and opinions of e-cigarettes along with baseline demographics such as previous quit attempts. One survey16 found a statistically higher amount of throat burning in current smokers versus former smokers and in e-cigarettes with nicotine versus e-cigarettes without nicotine. No differences were found for the side effect of dry mouth/throat.
I perused PubMed for data on e-cigarette safety, and I was appalled at the crappy quality of the studies out there. For instance, here are two more recent surveys compared to the review article I cited above. They tell us little or nothing more. Even surveys reporting adverse events are not particularly helpful. This Internet forum survey, for instance, has a built-in selection bias. Even though it tells us that there are a wide variety of reported effects from e-cigarettes, including cough, headache, panic, nausea, tremor, fatigue, reflux, throat and mouth irritation, burning, dermatitis, and elevated blood pressure, it’s hard to tell what the true prevalence of such reported symptoms are. Not surprisingly, given the uncontrolled nature of these studies, they showed that smokers generally liked e-cigarettes, think they help them decrease or quit smoking, and don’t cause any significant problems. It’s simply amazing how little hard data there are published. Moreover, most of these studies were prone to selection bias because they tended to recruit subjects from visitors to e-cigarette manufacturer websites and e-cigarette enthusiast blogs, and recall bias was certainly a concern given that these studies had no independent verification of smoking cessation. In other words, these surveys are pretty much useless.
In 2009, the FDA was concerned about the content of e-cigarettes and undertook an analysis of two leading brands of e-cigarette cartridges and found that one out of the 18 cartridges contained 1% diethylene glycol, an ingredient in antifreeze that is toxic to humans. Also noted were “certain tobacco-specific nitrosamines which are human carcinogens” in half the samples tested. Other findings included:
- Tobacco-specific impurities suspected of being harmful to humans—anabasine, myosmine, and β-nicotyrine—were detected in a majority of the samples tested.
- The electronic cigarette cartridges that were labeled as containing no nicotine had low levels of nicotine present in all cartridges tested, except one.
- Three different electronic cigarette cartridges with the same label were tested and each cartridge emitted a markedly different amount of nicotine with each puff. The nicotine levels per puff ranged from 26.8 to 43.2 mcg nicotine/100 mL puff.
- One high-nicotine cartridge delivered twice as much nicotine to users when the vapor from that electronic cigarette brand was inhaled than was delivered by a sample of the nicotine inhalation product (used as a control) approved by FDA for use as a smoking cessation aid.
These findings have been disputed. For instance, it has been pointed out that the tobacco-specific nitrosamines found by the FDA are present in e-cigarette vapor are present at much lower concentrations than in cigarette smoke and comparable to what is found in nicotine patches. Given that the only chemicals found in e-cigarettes that raise significant health concerns are tobacco-specific nitrosamines and diethylene glycol (believed to be a contaminant from the use of non-pharmaceutical grade polyethylene glycol), from the standpoint of the vapor, e-cigarettes probably are safer than regular cigarettes. A recent technical report from Igor Burstyn of Drexel University reports that the levels of contaminants e-cigarette users are exposed to are “insignificant, far below levels that would pose any health risk.” However, although it’s referred to in various places as a “study,” it really isn’t. It’s a review article, and it wasn’t even a peer-reviewed article, simply a “technical report” posted at the Drexel website and touted by press release. It was also funded by Consumer Advocates for Smoke-free Alternatives (CASAA), a group that promotes “reduced-risk” alternatives to cigarette smoking, including e-cigarettes. To be honest, given the funding source of this review and its lack of publication in a peer-review journal — one blog comment hilariously states that the study “has been made public for peer review. As CASAA promised when fundraising, the researcher would not keep the study results a secret from the public during the review process” — I’m less than impressed, for obvious reasons. And for shame, ACSH, for promoting this piece of propaganda! If you think I’m being too hard on ACSH, then just imagine what its reaction would be if a supplement company pulled this sort of stunt, publishing a “technical report” that’s not peer-reviewed and promoting it. Or if someone who doesn’t share its sterling view of e-cigarettes tried it.
Other studies have evaluated the effects of e-cigarette use on various measurable endpoints, such as plasma nicotine levels, heart rate, and expired carbon monoxide concentrations, but these were all short term studies using surrogate endpoints. Another study comparing tobacco cigarettes and e-cigarettes found that e-cigarette vapors produced smaller changes in lung function than tobacco smoke, but resulted in similar levels of nicotine in the blood as measured by the metabolite cotinine, while another study supports the observation of at least some adverse physiologic changes due to e-cigarette vapor. Specifically, use of an e-cigarette for 5 min was found to cause an increase in impedance, peripheral airway flow resistance, and oxidative stress among healthy smokers. On the other hand, this increase was small, and it is unclear what its clinical significance may be.
Given that e-cigarettes are too new for long-term studies to have been done, harm from the vapor can’t be ruled out, but it’s not unreasonable to provisionally conclude that it probably is less than tobacco smoke. The problem is that that’s a really low bar to clear, given how incredibly harmful tobacco-containing cigarettes are known to be, and says nothing about whether e-cigarettes are acceptably safe. The other problem, of course, is that that rigorous, well-conducted, long-term studies on e-cigarette safety are basically nonexistent. All we can do is extrapolate from surveys, chemical analyses, and generally low-quality data, and there’s a lot of uncertainty in doing so.
Are e-cigarettes effective smoking cessation aids?
The vapor is not the only issue with respect to e-cigarettes, though. They are, after all, intended as nicotine delivery devices, oddities in the law here in the US notwithstanding that classify them as tobacco products even though they contain no tobacco. Although manufacturers are not allowed to make the claim that e-cigarettes are useful smoking cessation aids, promoters of e-cigarettes as a harm reduction strategy, like the ACSH, are not nearly so shy about trumpeting such claims far and wide, even to the point of claiming that attempts to ban or strictly regulate e-cigarettes will “kill smokers,” presumably by robbing them of their one and only chance to quit smoking. It’s massive hyperbole, of course, because data are so lacking, and these are the claims that set my skeptical antennae a’twitchin’.
So what about nicotine? One concern the FDA reported was a highly variable nicotine delivery rate per puff from cartridge to cartridge of the same brand. (One notes at least one other study citing variable nicotine content in e-cigarette cartridges.) That suggests poor manufacturing processes and lack of standardization that are concerning. In addition, e-cigarettes appear to deliver less nicotine compared to FDA-approved nicotine inhalers, as measured by peak plasma concentrations after 10 puffs. According to manufacturers, these cartridges generally contain between 6 and 26 mg of nicotine, although there are cartridges on sale that contain as much as 45 mg of nicotine. In comparison, a typical cigarette generally delivers approximately 1 to 3 mg of absorbed nicotine. However, e-cigarette cartridges are not meant to be the equivalent of one cigarette; so a one-to-one comparison is difficult, as a typical cartridge is the equivalent of up to a pack of cigarettes, as many as 350 puffs.
When I perused PubMed looking for studies on the efficacy of e-cigarettes as a smoking cessation aid, I was no longer surprised to note an extreme paucity of them. There are to date no randomized double-blind controlled trials. Zero. Zip. Nada. In fact, I could find only two studies that weren’t in my opinion such dreck that they weren’t worth bothering to mention, and the larger and better designed of the two was essentially negative. First, there was a randomized, single-blind study by New Zealand researchers with a cross-over design in which subjects who smoked more than 10 cigarettes a day for at least one year who weren’t trying to quit used either a nicotine inhaler, a no-nicotine e-cigarette, a 16 mg nicotine e-cigarette, or their own cigarettes for a nine hour period. The results? The 16 mg e-cigarette and the nicotine inhaler produces a similar reduction in the desire to smoke compared to the no-nicotine e-cigarette. It was a small study, of course, and only looked at short-term surrogate outcomes. As such, it says little about the use of e-cigarettes as a smoking cessation aid other than that they might be useful.
More recently, there was a larger study of a similar design from an Italian group published in PLoS ONE. It was larger study (300 smokers) looking at three different strengths of a popular e-cigarette in Italy. Group A (n = 100) received 7.2 mg nicotine cartridges for 12 weeks; Group B (n = 100), a 6-week 7.2 mg nicotine cartridges followed by a further 6-week 5.4 mg nicotine cartridges; Group C (n = 100) received no-nicotine cartridges for 12 weeks. Subjects underwent nine visits during which cigarette use and exhaled carbon monoxide levels were measured. Interestingly, declines in cigarettes/day use and eCO levels were observed at each study visit in all three groups with no clear consistent differences between study groups in rates of smoking cessation and declines in cigarette use. There was no difference in adverse events, either, including dry cough, mouth irritation, shortness of breath, throat irritation, and headache. In other words, it was a negative study, but that’s not how it was spun. Not surprisingly, the authors argued that e-cigarettes are useful adjuncts to smoking cessation.
My interpretation? There was no real control group, and this study suggests that it doesn’t matter whether there is nicotine in the e-cigarette or not. Moreover, there’s no way of knowing whether there was selection bias, and 40% of subjects didn’t show up for their last visit. From my perspective, the Hawthorne effect, in which the simple process of observation results in improvement in behavioral studies regardless of the intervention tested, could potentially account for this result. That’s why appropriate control groups are so essential. (I bet that if there were a no-intervention “observation only” group and a nicotine patch control group, there would have been a significant decline in smoking in those groups as well.) Sadly, the authors didn’t even mention that possibility.
As I said before, the question of whether e-cigarettes are a useful smoking cessation aid is a question that cries out for a decent randomized, double-blind controlled trial and a trial comparing them to conventional methods currently used for smoking cessation. As anyone who’s ever smoked or dealt with smokers know, smoking cessation is an incredibly difficult nut to crack. Even the treatments that work don’t work all that well. As far as e-cigarettes go, the best I could find was a proposed protocol from investigators in New Zealand for a randomized double-blind, placebo-controlled trial:
Design: Parallel group, 3-arm, randomised controlled trial. Participants: People aged ≥18 years resident in Auckland, New Zealand (NZ) who want to quit smoking. Intervention: Stratified blocked randomisation to allocate participants to either Elusion™ e-cigarettes with nicotine cartridges (16 mg) or with placebo cartridges (i.e. no nicotine), or to nicotine patch (21 mg) alone. Participants randomised to the e-cigarette groups will be told to use them ad libitum for one week before and 12 weeks after quit day, while participants randomised to patches will be told to use them daily for the same period. All participants will be offered behavioural support to quit from the NZ Quitline. Primary outcome: Biochemically verified (exhaled carbon monoxide) continuous abstinence at six months after quit day. Sample size: 657 people (292 in both the nicotine e-cigarette and nicotine patch groups and 73 in the placebo e-cigarettes group) will provide 80% power at p = 0.05 to detect an absolute difference of 10% in abstinence between the nicotine e-cigarette and nicotine patch groups, and 15% between the nicotine and placebo e-cigarette groups.
Which is what is desperately needed, a head-to-head comparison between e-cigarettes with nicotine, without nicotine, and nicotine patch alone. I hope these investigators succeed in getting this trial going and that it produces clearly interpretable data. This is a question that needs to be answered. Badly.
The bottom line
E-cigarettes started out as a promising idea that turned into a product that got away “into the wild,” so to speak, before being adequately studied. Originally conceived as a safer way for a smoker to get is nicotine fix, e-cigarettes have evolved into a fad driven by claims that they are much safer and promoted by e-cigarette companies and now by the big tobacco companies that are frantically buying up e-cigarette companies and/or introducing their own brands. Because, through a quirk in US regulatory law, they are currently unregulated, which has led to a proliferation of many, many brands of variable design and reliability. Although short term studies of e-cigarettes appear not to have found any evidence of significant harms, there are currently no solid long term data regarding the effects of inhaling the vapors produced by e-cigarettes. A recent review concluded that the vapors are likely safe, but did so based on primarily on a review of chemical analyses of e-cigarette vapor. A more recent analysis finds some toxic chemicals in e-cigarette vapor butat much lower levels than in tobacco smoke. Again, however, there are no long term epidemiological or observational data in actual humans using e-cigarettes.
Given that e-cigarettes are being touted as a replacement for smoking and thus presumably for long term use rather than short term use as a tool to quit smoking, this is a rather glaring problem. Moreover, we don’t know yet whether long term use of nicotine delivered in this manner is safe. Nicotine is, after all, an addictive drug whose use results in vasoconstriction, increasing heart rate and blood pressure, as well as inducing a combination of free radical production, vascular wall adhesion, and a reduction of fibrinolytic activity in the plasma that might be an indication of contributing to atherosclerosis. It might be safe delivered this way. It might not. We don’t know.
Despite all the uncertainty, on the one side we see anti-tobacco activists proclaiming e-cigarettes to be potentially harmful and gateway drugs to children leading to the use of real tobacco, while on the other side we see e-cigarette promoters (and I do count ACSH among that group) making concreted, absolutist statements that e-cigarettes are safe and effective aids to smoking cessation. The evidence base is such that both are overstating their cases, although I tend to conclude that the e-cigarette apologists are overstating their case more, given the apocalyptic rhetoric of regulators killing smokers. The hypocrisy of some of the rhetoric is astounding, attacking apologists for unregulated supplements for promoting them, while simultaneously blasting critics of unregulated e-cigarettes! Meanwhile harm reduction seem to have no qualms about citing testimonials selection bias-laden surveys as “evidence” that e-cigarettes definitely help smokers quit. Quite frankly, I don’t get it. Would the same people accept such low quality evidence in support of, say, supplements? Or claims that e-cigarettes are a “gateway” to tobacco smoking? Surveys routinely show that people love their supplements and believe them to improve their health. Accepting such low quality evidence for the efficacy of e-cigarettes in the same thing as accepting surveys data as evidence for the efficacy of supplements, and it distresses me how many are either unable or unwilling to understand that.
I can understand provisionally concluding that e-cigarettes are safer than cigarettes (they likely are), but the evidence that e-cigarettes are an effective aid to smoking cessation is currently slim to non-existent, much less any evidence that they are more effective than nicotine patches or inhalers, as is sometimes claimed. Making definitive statements about the safety or efficacy of e-cigarettes is not an evidence-based stance. An evidence-based stance towards the question of whether e-cigarettes are an effective smoking cessation aid is, “We don’t know yet. Rigorous studies are desperately needed.” At least, that’s my story, and I’m sticking to it. As I said early on in this post, when it comes to e-cigarettes, I have been and remain agnostic, particularly in light of the massive advertising and promotional campaigns designed to sell them. To me, today, that is the correct science- and evidence-based stance. Show me some decent evidence, and I will change that stance. In other words, put up or shut up.