Vaping and Health: What We Know So Far
July 16, 2015
News, Knowledge
At the center of all the buzz around these no-longer-so-newfangled vaping devices that have been skyrocketing in popularity over the past decade is one very important question that researchers, regulators, manufacturers, distributors, and users have been working hard to answer: what impact does vaping have on human health? This question can also be subdivided into two separate but similarly important questions: "how does the health impact of vaping compare to smoking?", and "how does the health impact of vaping compare to not vaping?" Neither of these questions have simple answers right now, but we are not at all in the dark either. The research is pouring in every day, and we know a whole lot about how e-cigarettes are likely to impact the health of users right now.
What's in the vapor?
E-liquid usually contains nicotine (but not always), propylene glycol (PG) and/or vegetable glycerine (VG), and FDA-approved food flavorings (though some people prefer to go flavorless). And that's it. Well, unless you're vaping some of this wacky stuff.
It should be noted here, though, that e-cigarettes technically produce a liquid aerosol, like fog, and not an actual vapor, like steam. Producing an inhalable vapor from e-liquid would require much hotter temperatures which would likely cause severe burns in the mouth, throat and lungs, and the heat required may drive unwanted, unpalatable, or hazardous chemical reactions (just like burning your food does). The fact that it is an aerosol is a good thing, though anti-vaping zealots may try to convince you otherwise.
Is it safe to inhale nicotine?
Yes. The only risk found so far in consuming typical dosages of nicotine is in the fetal development of pregnant women who use nicotine (though it should be noted that there are about 30 other compounds in cigarette smoke that contribute to fetal development issues), and in the developing brains of children and adolescents (though it should be noted that evidence of this is taken from animal studies, and isn't particularly strong). For adults who are not pregnant, nicotine replacement medications and devices are considered very safe, are on the WHO Model List of Essential Medicines, are often offered over the counter, and include nicotine inhalers. Nicotine is not carcinogenic or known to be otherwise harmful at recreational or therapeutic doses in adults.
Is it safe to inhale propylene glycol?
Yes, unless you happen to be allergic or sensitive, which is very rare. PG is found in various foods, coffee-based drinks, liquid sweeteners, ice cream, soda and alcoholic beverages, fog machines, shampoos, cosmetics and other personal care products, vaporizers used for delivery of pharmaceuticals, and it's used as a solvent in many oral, injectable, and topical medications.
You may hear people on the other side continually vomiting up this illogical 'guilt by other uses' argument, where they try to make the case that PG is antifreeze, and that therefore it's bad for you. The logic used in this argument seems to often be intentionally deceitful, as it's made by people with academic credentials that suggest they must know better.They try to conflate it with ethylene glycol, which is toxic if ingested, when the fact of the matter is that propylene glycol is only used as a substitute for ethylene glycol in applications where a low toxicity, environmentally friendly antifreeze is needed.The fact that propylene glycol has a low freezing point does not make it dangerous to consume.
Is it safe to inhale vegetable glycerin?
There's no reason to believe it isn't. This substance, also known as glycerol, is used in food, fog machines, medical, pharmaceutical, and personal care preparations, is generally recognized as safe for those applications, and has not been found to cause issues when inhaled.
Glycerol is a sugar alcohol that plays an essential role in human metabolism, and acts as the backbone of the major classes of biological lipids, such as triglycerides.
Not only has evidence not shown any risks associated with inhalation, but no mechanism by which inhaled glycerin could cause harm has even been suggested.
Is it safe to inhale "flavorings"?
Here is where things get a little murky. "Flavorings" is a word we use to cover a multitude of compounds. We just write "flavorings" on food ingredient lists because these tend to be mixtures of so many substances that listing them all on a label would require bigger packages and wouldn't leave room for anything else. It also wouldn't typically offer any useful information to the consumer. For instance, what good would it do to label the full chemical composition of a banana? All we need to know is that there's no good reason to believe these compounds are dangerous to eat, and the FDA is responsible for assuring us of that.
A natural flavoring is "the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or any other edible portions of a plant, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose primary function in food is flavoring rather than nutritional", and an artificial flavoring is pretty much anything else whose primary function in food is flavoring rather than nutritional. Both are used in e-liquids, and there's no reason to think the mostly arbitrary "natural" or "artificial" labels give us any information about their potential for toxicity or allergenic properties.
The trouble for vapers, though, is that there are some compounds which may generally be safe to eat, but harmful to inhale. Diacetyl, acetylpropionyl, butyric acid, and acetoin, all of which are used as buttery flavors and three of which are naturally present in butter, are chemicals that may be in this category, and they are all found in many e-liquids.
While nobody (with any credibility) has suggested vaping e-liquids that contain these chemicals constitutes a hazard approaching that of smoking cigarettes, there is currently a movement in the e-cigarette industry working to identify e-liquids containing these chemicals and either remove those that contain high levels or at least let the consumer know they contain it so they can make an informed decision. It isn't known for sure at this point whether these substances in e-liquid actually cause any significant harm at all, but experts have recommended erring on the side of caution.
There may end up being other flavoring chemicals used in e-liquids that fall into the "safe to eat, maybe not so safe to inhale" category which have not yet been identified, but research has been conducted, and has not turned up anything worth worrying about. It should also be noted that many of these chemicals are used for the purpose of fragrance in foods and cosmetics, and in those cases they are also meant to be inhaled.
What about formaldehyde?
If you're reading this article, I'm going to assume you've heard reports that suggest there are dangerous levels of formaldehyde (or other aldehydes and ketones) in e-cigarette vapor. This is not true, and you can read what I've written on the matter here and read a follow-up here.
What else could be in my vape?
The atomizer in an e-cigarette consists of an absorbent wicking material and a conductive heating element, and this is where it's been suggested that other potentially hazardous substances could find their way into your lungs. So far though, analyses of vapor for toxic metals or harmful fibers has turned up nothing of note.
What about vaping with asthma or COPD?
From a recent, well-cited article by Dr. Riccardo Polosa, published in BMC Medicine:
"Although it is well-established that the inflammatory response to cigarette smoke plays a key role in COPD pathogenesis, increased morbidity and mortality have been reported in asthmatic individuals who smoke and quitting can significantly improve asthma symptoms and lung function. Consequently, smokers with preexisting asthma and COPD may benefit from regular EC use. In the only clinical study conducted to ascertain efficacy and safety of EC use in asthma, substantial improvements in respiratory physiology and subjective asthma outcomes have been reported. Exposure to e-vapor in this vulnerable population did not trigger any asthma attacks."
"To date, no formal efficacy and safety assessment of EC use in COPD patients has been conducted. There is only evidence from a case series of three inveterate smokers with COPD, who eventually quit tobacco smoking on their own by switching to an EC. Significant improvement in quality of life and reduction in the number of disease exacerbations were noted. EC use was well tolerated with no reported adverse events."
Patients with asthma and COPD seem to do very well on electronic cigarettes, especially when compared to smoking, but the data here is still very sparse, and limited to only a couple of case studies for COPD.
Where can I find more information?
Michael over at Ecig Alternative keeps an updated list of relevant research that I find myself browsing frequently, and Dr. Farsalinos—one of the world's top e-cigarette researchers—maintains a website full of up-to-date research, information, and analysis.
Be critical of headlines and don't put too much stock into a single study's conclusions without reading it yourself, or at least reading a critical assessment of it from someone who is knowledgeable on the subject. Many researchers who have no idea how e-cigarettes work and how they are used have generated studies which they later had to clarify after headlines ran amok with misleading information.
Written by: Shawn C. Avery
Editor-in-Chief at the Daily Drip and vaping enthusiast with a B.S. in physics and a couple of adorable cats. Follow me on Twitter.
source: http://blog.thedripclub.com/vaping-and-health-what-we-know-so-far
