June 24, 2021

I, Science

The science magazine of Imperial College

E-cigarettes are gaining popularity, but are they an effective aid to quitting smoking? ...

“They smoke for the nicotine, but die from the tar.” The verdict of one researcher on health risks facing smokers.

Like many people, Dr Jamie Brown feels that using e-cigarettes can reduce the damage caused by nicotine addiction because using e-cigarettes, or ‘vaping’, doesn’t involve burning tobacco – a process that releases tar and toxic chemicals into the lungs and throat. “Tobacco cigarettes will end up killing 50% of their users,” said Brown, “so e-cigarettes are a great deal safer.”

Research led by Brown at University College London found that as well as providing a less damaging alternative, e-cigarettes could also help smokers kick their smoking habit. His study included evidence from nearly 6,000 smokers over a five-year period and found that those trying to quit by themselves without professional medical support were 60% more successful when they turned to e-cigarettes for help. Vaping was also more effective for quitting smoking than other nicotine replacement aids like gum and nicotine patches.

Despite these findings, there is little consensus building. A review published in Deutsches Ärzteblatt International earlier this month led by Prof. Dr. Dennis Nowak from Ludwig-Maximilian University, Munich, insisted there isn’t sufficient scientific evidence that e-cigarettes can be used as a quitting aid. His international survey looked at key areas including the contents of the vapor, the opinions of users, how likely e-cigarettes are to cause nicotine addiction, and how they’re used. It concluded: “As yet, there is no clear scientifically justifiable position regarding e-cigarettes and tobacco cessation.” And that: “No clear recommendation about their use can be made.”

This damning verdict appears to drive a wedge between the positions of these two research groups but they do find some common ground. For instance, both agree that by far the most effective method to stop smoking is to seek professional medical support. Health professionals will typically recommend prescription drugs such as varenicline that satisfy the same receptors in the brain as nicotine, but more weakly than nicotine itself does. The action of the drug helps to gently reduce the smoker’s addiction. Tests have shown that smokers who take advantage of professional medical help are three to four times more likely to succeed in quitting. Another advantage of professional help is that the drugs themselves have to be made to the highest quality standards available. This contrasts with the criticism e-cigarettes have faced that levels of purity can vary between vendors. Unfortunately, only around 5% of quitting smokers go down the path of professional support.

Another point researchers agree on is that, despite concerns about impurity of the e-cigarette fluid, vaping is far less harmful overall than smoking tobacco. Brown expands: “We don’t have the long term picture on e-cigarettes but what we do have is quite a lot of data from the toxicology of the vapor as well as the liquids in the e-cigarette cartridges. They suggest that e-cigarettes are substantially safer than tobacco cigarettes.” The sentiment is echoed in Nowak’s review, which states the danger of e-cigarettes is orders of magnitude less than tobacco cigarettes but also adds doubt: “the variable composition of the fluids used in e-cigarettes introduces a degree of uncertainty.”

Moving forwards on this prickly issue is likely to prove slow and difficult, especially as commercial companies around the world have found vapers to be a growing and lucrative consumer market. Popularity of e-cigarettes along with their success in helping some smokers quit leaves many feeling there’s no urgency to regulate them as a medical aid. As Brown puts it: “The key advantage of e-cigarettes is that they deliver nicotine more safely. They’re a harm reduction tool.”


IMAGE: Alice Taylor