- Two weeks of vaping instead of smoking did not make any heart or lung test results worse in people with COPD.
- Diastolic blood pressure (the “bottom number”) was lower after the vaping phase than after the smoking phase.
- In people who really stuck to vaping and stopped cigarettes, a key measure of airway resistance in the lungs improved.
- Overall, the results suggest vapes could be a less harmful option than cigarettes for people with COPD who can’t or don’t want to stop nicotine completely.
Switching from smoking to vaping for just two weeks led to measurable improvements in blood pressure and airway resistance among people with chronic obstructive pulmonary disease (COPD), according to a new trial.
While the authors stress that longer-term research is needed, these early results suggest that substituting vapes for traditional cigarettes may offer short-term benefits for people with COPD who struggle to quit smoking.
The study, conducted at the University of Vermont, set out to compare the short-term cardiopulmonary effects of smoking versus vaping under tightly controlled conditions.
The researchers wanted to determine how vapes affect “people at high risk from continued smoking like those with chronic obstructive pulmonary disease (COPD)” before recommending them as a harm reduction tool.
To do this, the team recruited 21 adults aged 40 and older who had COPD and smoked at least five cigarettes a day. Each participant completed two randomly ordered two-week phases: one where they continued smoking their usual cigarettes, and another where they were asked to stop smoking entirely and use a study-provided JUUL device with tobacco-flavoured pods.
To ensure participants actually stopped smoking during the vaping phase, the researchers used breath tests every day. Many participants were successful: fourteen of the 21 were able to abstain from smoking on “at least 70 per cent of E-Cigarette phase daily check-ins.” These individuals, labelled “adherers,” provided some of the clearest evidence of the potential benefits of switching.
What improved when participants vaped instead of smoked?
The headline finding was that “No cardiopulmonary measures worsened after two weeks of exclusive e-cigarette use, compared to two weeks of exclusive cigarette use.”
That alone is noteworthy in a population with compromised lung function. But the study also found specific improvements:
- Blood pressure improved. The researchers reported a “significant main effect of phase on DBP,” showing that diastolic blood pressure increased after the cigarette phase compared with the e-cigarette phase. Among the adherers, this difference was even more pronounced.
- Airway resistance improved, specifically in the central airways. Among adherers, the study found “a significant decrease of R19 across phases,” referring to airway resistance measured at 19 Hz. The authors note that “the average R19 z-score following the E-Cigarette phase (-1.9) was lower than at intake (-0.9).”
Importantly, these short-term improvements occurred without any signs of new harm. The Public Significance Statement says: “No cardiopulmonary measures worsened.. E-cigarettes may be a safe alternative to combustible cigarettes for COPD patients.”
Why might vaping produce these improvements?
Traditional cigarettes expose the lungs and cardiovascular system to thousands of chemicals produced through combustion. The researchers point out that switching from combustion to aerosol delivery may reduce exposure to substances that raise blood pressure or irritate the airways.
They also note that lower levels of volatile organic compounds in vape aerosol “potentially” contribute to reduced airway resistance.
The role of incentives – and the risk of dual use
An important part of this study was ensuring participants actually substituted vaping for smoking rather than doing both. The authors directly address this risk, saying “dual use (concurrent use of both products)” is associated with worse health outcomes than smoking or vaping alone.
To promote total abstinence from cigarettes during the vaping phase, the study used financial incentives. This worked well for most, though not all, participants. The authors write: “Most of the participants (14/21) were able to abstain from combusted smoking during the e-cigarette phase.”
But they also note that seven participants did not meet the abstinence criteria, suggesting that higher incentive levels or additional support might be required in real-world settings.
What this study does – and does not – tell us
This was a short trial, and the authors are clear about the need for longer-term research. They caution that “evaluating longer durations of e-cigarette substitution is warranted to determine their safety.”
The study also did not include a phase where participants quit smoking without using vapes, leaving open the question of how much improvement comes from simply stopping smoking.
Still, the controlled design and daily measurements give this study unusual strength. The trial shows that, in the short term, switching entirely from smoking to vaping did not cause harm and may have produced measurable cardiopulmonary benefits.
This article is based on an accepted manuscript published in Experimental and Clinical Psychopharmacology. The manuscript may differ from the final version of record.
