Normal lung function, yet marked exercise intolerance
A University of Alberta study has quietly upended one of modern public health's most convenient assumptions: that vaping is a safer passage through youth. Researchers found that young adults in their early twenties — people whose lungs should be approaching their peak — already show reduced blood flow and significant exercise intolerance, damage arriving faster than it does in cigarette smokers and during the very years the respiratory system is still being formed. With roughly one million Canadians vaping regularly, the findings suggest a generation may be mortgaging the health of organs they haven't yet finished building.
- Young vapers in their early twenties are showing breathlessness and exercise intolerance at the intensity of a moderate walk — impairments that have no business appearing in bodies that should be at peak function.
- Standard lung tests returned normal results, masking damage that only revealed itself under cardiovascular stress — meaning the harm is real but invisible to the tools most commonly used to detect it.
- The speed of the damage is what alarmed researchers most: deterioration that takes years to accumulate in cigarette smokers is appearing far sooner in vapers, precisely when lungs are still maturing toward their age-25 completion.
- A University of Alberta team is now partnering with UBC to expand the study, tracking lung blood flow changes across a larger population to determine whether these early impairments are a reliable warning sign of serious future disease.
- The findings force a reckoning with how vaping has been marketed and regulated — not as a comparable risk to smoking, but potentially as a faster-acting harm delivered during the most vulnerable window of respiratory development.
Twenty young adults walked into a University of Alberta lab and, without knowing it, helped overturn a decade of assumptions about vaping's safety. They were regular e-cigarette users in their early twenties who had never smoked cigarettes or marijuana — people who had chosen what was marketed as the cleaner path. Pulmonary medicine professor Michael Stickland put them through cardiovascular stress tests, and what emerged was unsettling: asked to exercise at the pace of a moderate walk, they reported breathlessness that had no place in bodies that age. Their standard lung tests looked normal. Their bodies did not.
The detailed findings pointed to reduced blood flow to the lungs and marked exercise intolerance — not statistical whispers, but clear impairments in people who should have been at their physical peak. More alarming still was the timeline. Damage that typically takes years to develop in cigarette smokers was appearing far sooner in vapers, during the precise window — before age 25 — when the lungs haven't yet finished forming. Roughly one million Canadians vape regularly, many of them teenagers and young adults inhaling potentially toxic substances while their respiratory systems are still under construction.
For Stickland, a father of two teenagers, seeing the data was a career-defining moment. He described it as the first time he felt compelled to keep studying something not out of academic curiosity, but out of genuine concern. His team is now expanding the research in partnership with the University of British Columbia, launching a larger three-year study to track lung function across a broader population and understand the mechanisms driving the blood flow changes — and whether those early impairments reliably predict serious lung disease later in life.
The Alberta findings reframe vaping not as a comparable risk to smoking, but as a potentially faster-acting harm delivered at the worst possible time. The trade-off that was sold to a generation — cleaner, safer, a reasonable alternative — may have been far more costly than anyone realized.
Twenty people in their early twenties walked into a University of Alberta lab expecting routine health tests. What researchers found alarmed them enough to reshape how we think about vaping's safety.
These young adults had never smoked cigarettes or marijuana. They were vapers—regular users of e-cigarettes, devices marketed for years as a harm-reduction tool, a safer path than traditional smoking. But when Michael Stickland, a pulmonary medicine professor, put them through cardiovascular stress tests, something unexpected emerged. Asked to exercise at the intensity of a moderate walk, they reported breathlessness far beyond what a healthy 22- or 23-year-old should experience. Their lungs, by standard clinical measures, looked normal. Yet their bodies told a different story.
The detailed analysis revealed the problem: reduced blood flow to the lungs and diminished exercise tolerance. These weren't subtle findings buried in statistical noise. They were marked impairments in people young enough that their bodies should have been at peak function. "What was quite surprising is these 23-year-old individuals had normal lung function, yet they showed marked exercise intolerance and greater breathlessness," Stickland said. The three-year study, completed recently, documented early lung damage and heart dysfunction that researchers worry could seed serious disease later in life.
What made the findings particularly striking was the speed of harm. Damage that typically takes years to develop in cigarette smokers appeared much sooner in vapers. This matters because the human body doesn't finish developing until the mid-twenties. The lungs, specifically, don't fully mature until around age 25. A generation of teenagers and young adults—roughly one million Canadians vaping regularly—are inhaling potentially toxic substances during the precise window when their respiratory systems are still being built.
Stickland, a father of two teenagers himself, described the moment he saw the data as a turning point in his career. "I was quite concerned," he said. "It was the first time in my career where I said we really have to keep studying the effects, because the level of impairment we saw in their blood flow and exercise was concerning and suggested important changes in the lungs that we need to understand better."
The research team is now expanding the work. In partnership with the University of British Columbia, they're launching a larger, three-year study to track e-cigarette use and lung function across a bigger population. Locally, they'll focus on understanding what's happening to blood flow in the lungs—the mechanism behind the damage—and whether those early changes predict the development of serious lung disease down the road.
The implications are still unfolding. For years, vaping was presented as a cleaner alternative, a way for smokers to quit or for young people to avoid cigarettes altogether. The Alberta findings suggest the trade-off may be worse than anyone realized. The damage isn't just comparable to smoking; it appears to arrive faster, during years when the lungs are still forming. That's a different kind of harm—one that could reshape how regulators, doctors, and young people themselves think about these devices.
Notable Quotes
Early-life exposure to toxins can impair lung growth and predispose people to future lung disease.— Michael Stickland, pulmonary medicine professor, University of Alberta
We've now exposed a whole new generation to potentially toxic substances being inhaled through the lungs.— Michael Stickland
The Hearth Conversation Another angle on the story
Why does damage show up faster in vapers than in people who smoke cigarettes?
That's the question researchers are still working to answer. But the timing matters enormously. Cigarette smokers are usually older when they start, and their lungs have already finished developing. These vapers are in their early twenties, still in that critical window where the lungs are maturing. You're introducing toxins during the actual construction phase.
So it's not that vaping is inherently more toxic than cigarettes?
We don't know that yet. What we know is that the damage appeared sooner and was more pronounced than expected. It could be the substances in vape aerosol, or it could be the timing—hitting developing lungs versus fully formed ones. That's what the larger study is meant to clarify.
These young people had normal lung function on standard tests. How did researchers catch the problem?
Standard clinical tests are blunt instruments. They measure basic airflow and capacity. But when you stress the body—ask it to exercise—you see what the lungs can actually do. These young adults couldn't keep up. Their blood flow was reduced. Their bodies were telling the truth that the standard tests missed.
What happens to these people now? Do they have permanent damage?
That's unknown. The study tracked them for three years, but we don't have long-term follow-up data yet. The concern is that early impairment could predispose them to serious lung disease later. But whether it's reversible, whether it progresses, whether it matters at age 40—those answers aren't here yet.
Why is this study important beyond these twenty people?
Because one million Canadians are vaping regularly. Many are teenagers whose lungs haven't finished developing. If this pattern holds across a larger population, we're looking at a generation potentially facing lung disease they didn't expect. The device was supposed to be safer.