The pointed exchange comes amid growing controversy over the value of e-cigarettes, and how to weigh their role as a smoking cessation tool against their potential harms, especially among young people for whom vaping has soared in popularity. The statements align with others made by U.K. public health officials in recent months, which have generally supported vaping as a useful alternative to traditional cigarettes. In contrast, WHO’s cautions about vaping echo those voiced by the U.S. Centers for Disease Control and Prevention and some U.S. scientists, who are expressing alarm over both known and still-uncertain hazards from vaping. After an outbreak of severe lung disease that’s still being investigated and is linked to THC-containing e-cigarettes, CDC now recommends that e-cigarettes of all kinds “never be used by youths.”
In a document released Monday, WHO expressed reservations about the value of e-cigarettes and grave concerns about their risks. The organization stated “there is no doubt” that e-cigarettes “are harmful to health and are not safe, but it is too early to provide a clear answer on the long-term impact of using them or being exposed to them.” WHO also suggested “there is not enough evidence to support the use of these products for smoking cessation,” and urged smokers looking to quit to try nicotine patches or gum, or other tools such as hotlines that counsel smokers.
The U.K. response was harsh. “The WHO has a history of anti-vaping activism that is damaging their reputation. This document is particularly malign,” Peter Hajek, who directs the Tobacco Dependence Research Unit at Queen Mary University of London, wrote in a statement released today by the U.K. Science Media Centre.
“There is no evidence that vaping is ‘highly addictive,’” he said. “Less than 1% of non-smokers become regular vapers. Vaping does not lead young people to smoking—smoking among young people is at [an] all-time low. … There is clear evidence that e-cigarettes help smokers quit,” Hajek continued.
E-cigarettes are “clearly less harmful” than tobacco, said John Britton, director of the UK Centre for Tobacco & Alcohol Studies and a consultant in respiratory medicine at the University of Nottingham, in similarly critical comments. “WHO misrepresents the available scientific evidence,” he charged. Public Health England maintains that vaping is “at least 95% less harmful than smoking cigarettes.”
Earlier this month, a team of six experts disputed that 95% claim in a publication in the American Journal of Public Health. Led by Thomas Eissenberg, a psychologist at Virginia Commonwealth University who co-directs the Center for the Study of Tobacco Products and serves as a paid consultant in litigation against the tobacco and e-cigarette industries, the authors suggested there is an “accumulation of evidence of potential harm” from e-cigarettes and “growing evidence that e-cigarette use is associated with subsequent cigarette smoking.” Although tobacco use among U.S. middle and high school students has dropped, a 2017 study in JAMA Pediatrics reported that across seven studies that examined initiation of smoking in teenagers and young adults, those who had used e-cigarettes had a 23% chance of starting to smoke, compared with a 7% chance when there was no e-cigarette use.
The short- and long-term risks of e-cigarettes continue to be investigated; whereas many believe the products are lower risk than cigarettes, others say the jury is still out. Studies in animals and people are now exploring whether e-cigarettes pose chronic risks to the lungs and cardiovascular system.
The question of whether e-cigarettes help smokers quit, and at what cost, remains controversial. Tobacco kills more than 8 million people a year worldwide, and many smokers have shared publicly that e-cigarettes helped them. A randomized trial run by Hajek and others reported a year ago in The New England Journal of Medicine that e-cigarettes were more effective tools than nicotine replacement therapy when it came to helping smokers quit. As happens often in the vaping field, however, the data came under scrutiny: Subsequent letters to the journal noted, among other concerns, that 40% of the 438 participants assigned to e-cigarettes as a quitting tool were still using them after 1 year, and one-quarter of those in the e-cigarette group wound up becoming “dual users,” meaning they both vaped and smoked.
The dispute is unlikely to be resolved soon. But for WHO, the downside of e-cigarettes clearly outweighs their benefits. E-cigarettes “are currently banned in over 30 countries worldwide,” the group shared this week, “with more and more countries considering bans to protect young people.”