Everything We Know About E-Cigarettes So Far

This article first appeared on Tonic US.

Show of hands: Who’s heard an e-cigarette user say “it’s just water vapour”? Yeah, most of us. And as you can probably imagine, it's…not just water vapour.

“The hope for e-cigarettes was that they would give people an alternative way to inhale nicotine that’s not as dangerous as a cigarette,” says Stanton Glantz, a professor of medicine at the University of California, San Francisco. “While that was a rational hope, it has turned out to not be the case.”

Glantz and other e-cigarette researchers say much is still unknown when it comes to the health effects of vaping devices. But hundreds of e-cigarette studies have come out in just the past two years. And experts say the more we learn about e-cigarettes, the more they’re starting to look like traditional tobacco cigs.

“If you go back a couple years, everyone was saying [e-cigarettes] were probably 95 percent safer than traditional cigarettes,” Glantz says. “Even two years ago, I was telling people they were probably a third as bad.”

Today, he tells people e-cigarettes are two-thirds as bad as traditional cigarettes—and his assessment may grow even more pessimistic. “Every month they seem to look more dangerous,” he says.

In February, a study from Johns Hopkins Bloomberg School of Public Health turned up lead, nickel, and toxic metals in the vapour produced by e-cigarettes. “We had a hunch there may be metals because of the coil used to heat up and aerosolised the vapour,” says Ana Rule, an assistant professor of environmental health and engineering at Hopkins and co-author of the study.

That hunch proved correct. “We found lead and manganese, which have been shown to be neuro-toxicants,” Rule says. She and her colleagues also turned up chromium and nickel, which can cause cancer.

Rule says many of these metals are also found in traditional cigarettes, albeit in different concentrations. “We don’t know what the health effects of these metals are, but e-cigarettes may be just as concerning as [traditional] cigarettes,” she says.

Another just-published study found adolescent e-cigarette smokers’ urine tested positive for at least five of the same cancer-causing chemicals found in traditional cigarettes. “The two main solvents found in the [e-cig] juice”—propylene glycol and glycerol—"are FDA-approved as food and at food temperatures, but when heated to the point of vaporisation they can produce carcinogenic compounds,” says study co-author Mark Rubinstein, a professor of paediatrics at UCSF. A 2015 study found these two e-cig solvents, when vaporised, can produce formaldehyde—another carcinogen.

All this helps dispel another myth passed among e-cigarette users, which is that the “juice” in vape pens and other devices is “food grade” and therefore safe. “Something may be safe for consumption, but that’s very different than saying it’s safe to inhale into the lungs,” says David Eaton, a professor of toxicology at the University of Washington who helped produce a 2018 consensus study on e-cigarettes for the National Academies of Sciences, Engineering and Medicine.

Rubinstein adds that his study (and many others) only looked at the components of e-cigarettes that are also found in traditional cigarettes. “There may be many more toxins we don’t know about—including in the flavourants and the plastics where the juice is stored,” he says.

Probably. Eaton says the type and amount of “mutagenic” agents in e-cigarettes—that is, the stuff that can cause genetic mutations, and potentially cancer—can vary widely depending on a device’s liquid, battery strength, user characteristics (like how hard he or she draws), and other factors. “For example, one risk we know about is the production of aldehydes like formaldehyde, which is typically low [in e-cigarettes],” he says. “But in some battery-powered devices, that production is alarmingly high.”

Rubinstein points out that the production of vape pens and other e-cigarette devices—as well as their liquids—is largely unregulated. “Manufacture of these products is mostly in other countries without FDA oversight, so who knows what’s in the plastics or in these chemicals,” he says.

“Quality control has been a problem since the beginning with e-cigarettes,” adds Erika Sward, a spokesperson for the non-profit American Lung Association. She says that one of the challenges swirling around e-cigarettes is that there are nearly 8,000 products on the market today. “There are no quality standards and there no requirements to have nicotine levels [listed accurately] on packaging,” she says.

Despite what the vape shop owner may tell you, no one can predict with confidence what short- or long-term health risks may be linked to the device or juice you just purchased.

The jury’s still out.

Eaton’s report for the National Academies concluded that e-cigarettes “may” help longtime smokers kick the habit. “You hear lots of positive anecdotes if you talk to people, but e-cigarettes’ efficacy [as a quitting tool] compared to nicotine gum or patches is uncertain,” he says. “What is clear is if someone is smoking combustible tobacco and they start smoking e-cigarettes, if they don’t stop smoking combustible tobacco, e-cigarettes are not providing any net health benefit.”

A study published just last week in Annals of Internal Medicine found that heavy smokers who attempted to quit with the help of e-cigarettes were less likely to be successful after six months than smokers who didn’t use e-cigs. This is one of many studies to show that using e-cigarettes alongside traditional tobacco smokes—as opposed to making a wholesale, long-term switch—is unlikely to to help people quit.

“I don’t think we should be giving up on e-cigarettes, but I think the message from our study is that using [e-cigarettes] occasionally with traditional tobacco cigarettes won’t lead to cessation,” says Nancy Rigotti, a professor of medicine at Harvard Medical School and lead author of the study.

Others put a less hopeful twist on the existing research. “For most smokers, e-cigarette use seems to make it harder to quit,” UCSF’s Glantz says.

He says there’s some evidence that, for long-term heavy smokers—the 60-year-old who smokes two packs a day and thinks quitting is impossible—switching to e-cigarettes may be helpful. “But what we’ve found is that there are very few of these hardcore smokers left,” he says. The vast majority of smokers—something on the order of 95 percent—are not pack-a-day fiends, he says. And so for most smokers, e-cigarettes are “at best a distraction, and at worst something that is prolonging an epidemic,” he says.

In fact, e-cigarettes may be fueling a new epidemic.

Eaton’s report for the National Academies found that young people use e-cigarettes more than adults, and that—setting aside the inherent risks of using e-cigarettes—vaping may increase the odds that a teen or young adult will start smoking traditional tobacco cigarettes.

“E-cigarettes may help youths sort of adapt to inhaling nicotine so that, when they do take a puff of a regular cigarette, it’s not as harsh,” Eaton says.

Glantz adds: “There may be a huge gateway effect in terms of bringing kids into the nicotine market who would have been very unlikely to start using traditional cigarettes.”

He and others highlight some of the candy- or dessert-themed vape juice flavours—everything from “ crème brulee” to “ unicorn puke”—and say that these are far more likely to appeal to teens than to adult smokers hoping to kick their tobacco habit.

Even if you ignore all the evidence linking e-cigarettes to toxic metals and aldehydes, the nicotine in the juice is still bad for young people. “The US Surgeon General has concluded that there is no safe level of nicotine exposure for kids,” Sward says. “Exposure to nicotine permanently alters adolescent brain development, and that could make them more susceptible to addiction in other areas.”

Public health officials say e-cigarette flavours should be restricted the way they are in traditional cigarettes. (Tobacco cigarettes can only be sold in plain or menthol varieties, though menthol may be on the chopping block. Clove-, fruit-, and candy-flavoured cigs were outlawed in 2009.)

“Flavours like unicorn barf or Fruit Loops—these do not seem to be targeting adults,” Rubinstein says. “I’m shocked that these flavours are still allowed.”

Glantz reiterates this point and says local health authorities in San Francisco are currently trying to enact a ban on these kid-friendly flavours. But he says the ban is encountering tremendous pushback from Big Tobacco and e-cigarette manufacturers. “I think this will be a seminal fight,” he says. “If San Francisco can get this passed, I think we’ll see a lot of laws like this enacted.”

Returning to federal oversight, Eaton says the FDA should consider implementing quality-control regulations that mimic some of the existing or proposed tobacco laws. “E-cigarettes are nicotine delivery systems, and right now the nicotine levels are all over the place,” he says. (The FDA is currently considering limiting the amount of nicotine in cigarettes.)

Most experts also agree FDA should rein in e-cigarette manufacturer’s smoking-cessation claims until there’s stronger data to back them up. “FDA needs to be the independent science-based agency that determines whether these therapeutic claims are valid,” Sward says.

Finally, she and others say it’s time regulators stopped talking about the risks of e-cigarettes only in relation to traditional cigarettes. “Cigarettes are the most deadly consumer product on the market,” she says. Being safer than cigarettes isn’t exactly a high bar to hurdle.