- Smokers given a 5% nicotine vape were more than three times as likely to quit cigarettes after six weeks as those given a nicotine-free vape.
- The trial found 36.5% of people in the nicotine vape group stopped smoking, compared with 11.5 per cent in the zero-nicotine group.
- The nicotine vape group also had lower levels of some harmful chemicals linked to cigarette smoke.
- Researchers said vapes that deliver nicotine in a similar way to cigarettes may help reduce exposure to toxicants caused by smoking.
Smokers who switched to nicotine vapes were more than three times as likely to quit cigarettes as those given nicotine-free devices, a new randomised clinical trial has found.
The study, published in JAMA Network Open, adds to growing evidence that nicotine vapes can help adult smokers move away from combustible tobacco – the part of smoking that causes most disease.
Researchers at Penn State College of Medicine recruited 104 adults who smoked at least five cigarettes a day and were interested in switching completely to a vape. Half were given a pod-based vape containing five per cent nicotine, while the other half were given an identical-looking vape with no nicotine.
Neither the researchers nor the participants knew which group they were in during the six-week trial.
By the end of the study, 19 out of 52 people in the nicotine vape group had stopped smoking cigarettes, compared with six out of 52 in the nicotine-free group. That means 36.5 per cent of those using the nicotine vape were abstinent from cigarettes, compared with 11.5 per cent of those using the placebo device.
The researchers described this as “The tripling of biochemically verified cigarette abstinence rates with a 5 per cent SREC (36.5 per cent) vs a 0 per cent SREC (11.5 per cent)”.
Why nicotine made a difference
The trial is important because both groups were given a vape-like product. The key difference was whether the device contained nicotine.
That matters because it helps separate the behavioural side of vaping – the hand-to-mouth action, inhaling and using a device – from the pharmacological effect of nicotine itself.
The results suggest that nicotine delivery was central to helping smokers stay away from cigarettes. People using the five per cent nicotine vape reported lower withdrawal symptoms at one week and lower desire or craving to smoke at both one and six weeks.
The study also found that the five per cent nicotine device delivered nicotine in a way that was closer to cigarettes. In a small pharmacokinetic test, the researchers said the device produced a nicotine boost “similar to that produced by smoking a cigarette”.
For smokers who struggle to quit because of cravings and withdrawal, that may be the point. A vape that does not deliver nicotine may mimic the ritual of smoking, but it does not replace the nicotine smokers are dependent on.
Lower exposure to some harmful chemicals
The study also looked at whether switching from cigarettes to vapes reduced exposure to harmful chemicals.
The main measure was NNAL, a biomarker linked to NNK, a tobacco-specific lung carcinogen. NNAL levels were lower in the five per cent nicotine vape group after six weeks than in the zero-nicotine group, but the difference was not statistically significant after controlling for key baseline factors.
That is an important caveat. The trial does not show a clear statistically significant difference between the two groups on its primary outcome once those adjustments were made.
However, the nicotine vape group did have significantly lower levels of two other toxicant biomarkers: CYMA, linked to acrylonitrile, and 3HPMA, linked to acrolein. The study describes acrylonitrile as “a carcinogen” and acrolein as “a cardiac toxicant”, with both listed as respiratory toxicants.
Those who had stopped smoking at six weeks had far lower levels of NNAL, CYMA, 3HPMA and exhaled carbon monoxide than those who were still smoking.
In plain English, the biggest reductions in harmful exposure came when people actually stopped smoking cigarettes.
Not risk-free, but lower risk than smoking
The findings do not mean vapes are risk-free. They do show that, for adults who smoke, switching completely from cigarettes to nicotine vapes can reduce exposure to some of the toxic substances produced by burning tobacco.
Nicotine is addictive, but the major health danger from smoking comes from combustion – the burning of tobacco and inhalation of smoke.
The researchers wrote: “ECs that deliver nicotine like a cigarette may have an important role in reducing the harmful toxicant exposure caused by cigarette smoking and in helping people who smoke to quit smoking completely.”
The study also points to a policy problem. If the most effective products for adult smokers are those that deliver nicotine well enough to compete with cigarettes, then rules that make these products less available, less appealing or less satisfying could risk weakening their usefulness as a smoking substitute.
What the study can and cannot prove
The trial had several strengths. It was randomised, placebo-controlled and double-blind, meaning the comparison between nicotine and non-nicotine vapes was stronger than in many observational studies.
But it also had limits. It was small, with 104 participants, and ran for only six weeks, with a further check-in at 10 weeks. It was carried out at a single site in Pennsylvania, and the researchers noted that the sample “lacked racial and ethnic diversity”.
The trial also used only tobacco-flavoured pods. The authors said results may have been different if participants had used other flavours or been able to choose their preferred flavour.
Even with those caveats, the study’s central finding is hard to ignore. Adult smokers given a nicotine vape were substantially more likely to quit cigarettes than those given a nicotine-free version of the same device.
