Smoking is the leading preventable cause of death in the US, and vaping companies have long claimed their e-cigarettes can help smokers quit. But what do we really know about how well they work?
The short answer: Not much.
Until now, there were only two randomized control trials — considered the gold standard of scientific evidence — on e-cigarettes, both published in 2013. One showed e-cigarettes “were modestly effective” at helping smokers quit and that they worked about as well as nicotine patches. The other showed that e-cigarettes, with or without nicotine, seemed to help people stay away from conventional cigarettes.
Together, these studies were promising — but not enough evidence from which to draw clear conclusions. Doctors have consequently continued to wonder how truly helpful e-cigarettes are.
On Wednesday, the New England Journal of Medicine published another randomized trial on e-cigarettes. Led by researchers at Queen Mary University in London and funded by Britain’s National Institute for Health Research and Cancer Research UK, the study showed people who were randomly assigned to use e-cigarettes quit smoking at almost double the rate of people who were randomly assigned to nicotine replacement therapy.
That’s an impressive finding — making e-cigarettes look even more promising for smoking cessation. But don’t expect it to resolve the debate about their usefulness — or their risks. As usual, there are a bunch of caveats to consider in interpreting the study’s findings. In this case, many of them have to do with how quickly e-cigarette technology is changing and whether this UK study will translate to the US context. Here’s a quick rundown.
E-cigarettes were twice as effective as nicotine replacement therapy when used with counseling in the UK
For the new NEJM study, researchers recruited 886 patients who had been seeking help to quit cigarettes through the UK’s National Health Services stop smoking program. (Yes, the national health system there has free services to help people quit.)
Study participants were then randomly assigned to one of two treatment groups. One got free nicotine replacement products of the participant’s choice (such as patches and chewing gum) for up to three months. The other got a free e-cigarette starter pack — initially, an All-in-One starter kit from Aspire, and when that was discontinued, the One Kit 2016 from Innokin. They also got a bottle of tobacco-flavored nicotine vaping liquid, plus the recommendation to buy more e-liquids or flavors of their choice. The people in both groups received weekly in-person counseling on quitting and were followed for a year.
The study’s main findings:
- At the one-year mark, 18 percent of people in the e-cigarette group had abstained from cigarettes, compared to 10 percent in the nicotine replacement group.
- Participants in both groups said that e-cigarettes and nicotine-replacement products weren’t as satisfying as cigarettes — but the e-cigarette group rated the devices as more helpful and satisfying than the nicotine-replacement users rated their treatments.
- Interestingly, the successful quitters in the e-cigarette group were still overwhelmingly using them at one year, while those who stopped smoking in the nicotine replacement group mostly weren’t (80 percent compared to 9 percent). That means the e-cigarette users seemed to develop a reliance or habit the nicotine replacement users didn’t.
- As for side effects, the e-cigarette group had more mouth irritation but was also more likely to report a decline in coughing and phlegm. The nicotine replacement group, meanwhile, experienced more nausea.
Overall, e-cigarettes looked like pretty effective quitting aids compared to regular old nicotine-replacement therapy.
“I think smokers should be encouraged — if they find quitting difficult — to consider [e-cigarettes] and shop around and try to find a product which ticks the boxes for them,” said the study’s lead author Peter Hajek, the director of Queen Mary University’s health and lifestyle research unit. “Health professionals should now be able to say, ‘If you find quitting difficult, try this instead because there’s evidence.’”
But … not so fast
E-cigarettes may be better than the nicotine replacement alternative in the study — but they only helped a minority of participants in the vaping group quit. “In spite of the concerted effort and encouraging findings, it is still disappointing,” said David Liddell Ashley, the previous director of the office of science in the Center for Tobacco Products at FDA. “This points to the importance of further efforts, such as reducing nicotine in combusted products to encourage smoking cessation,” he added.
The other researchers I spoke to who weren’t involved in the study were also less enthusiastic. While they applauded the study’s size and rigor, they had some pretty big reservations — mostly to do with how the study can be extrapolated to a real-world, non-UK context.
A randomized control trial “does not resemble how e-cigarettes are used in the real world, particularly in the United States,” said Michael Eriksen, dean of the school of public health at Georgia State University and a former director of the Centers for Disease Control and Prevention’s Office on Smoking and Health.
Here in the US, there’s no freely offered guidance on quitting smoking through the government, he said, no face-to-face behavioral counseling like the participants got. There are also “confusing and contradictory media and public health messages on the relative safety of e-cigarettes in comparison to smoking.”
In the UK, the government has taken a firm harm-reduction stance on e-cigarettes. Public Health England endorses these devices as a safer alternative to cigarettes and vehicles that can help smokers quit. In the US, the Centers for Disease Control and Prevention and other government agencies are not actively endorsing e-cigarettes. Instead, they seem to be taking more of a zero-risk approach, viewing any harm e-cigarettes may cause as problematic and drawing attention to the rising use of e-cigs among American youth.
“[E-cigarettes] are much more acceptable as smoking cessation devices in the UK and are actively promoted by medical and public health groups, so the cultural context is much different,” Eriksen summed up.
Finally, we don’t know how relevant these findings are for smokers who might try to quit with newer products — such as Juul, which has devoured three-quarters of the US e-cigarette market. “They only used one type of e-cigarette in this trial,” a second-generation refillable e-cigarette that is popular in the UK, said Linda Bauld, professor of public health policy at the University of Edinburgh. “E-cigarette devices vary hugely so we can’t generalize the results of this trial to all e-cigarettes,” she added.
“The study is interesting but less significant than it’s being portrayed,” said Matthew Myers, the president of the Campaign for Tobacco-Free Kids. “It tells you that with counseling and under medical guidance, this particular e-cigarette form increased the chances of quitting. That’s all it tells you. That’s useful information. But it doesn’t tell you anything about any other e-cigarette, particularly when they’re used in a non-clinical setting.”
The study also doesn’t resolve the health controversy over vaping
Most public health officials agree that e-cigarettes are safer than regular cigarettes — one of the most harmful substances known to human health — and that individual adult smokers will likely benefit from making the switch.
But there are concerns about what vapor — and the particles it releases in the body — will do to the lungs and cardiovascular system over time, as well as whether they’ll put users at a higher risk of cancer. These concerns are especially acute for youth who weren’t smoking but are now vaping and whose developing bodies and brains are more susceptible to the effects of nicotine.
“While the findings are very good news for smokers,” said University of Waterloo tobacco expert David Hammond, “[the study] is unlikely to resolve the controversy over e-cigarettes and public health: the attributes that make e-cigarettes a more appealing mode of quitting for smokers also increase their appeal among youth.”
According to a new National Institutes of Health survey, which has tracked substance use among American adolescents, the number of high school seniors who say they vaped nicotine in the past 30 days doubled since 2017. That’s the largest increase ever recorded for any substance in the survey’s 43-year history. And it means a quarter of 12th-grade students are now using, at least occasionally, a nicotine device that’s so new we have no idea what the long-term health impact of using it will be.
So this randomized controlled trial might — and probably should — encourage health professionals to consider e-cigarettes, at least the type shown to be effective in the study, as a tool for their smoking patients. But it also shows e-cigarettes are far from the panacea some suggest they might be.