A young man wearing a stripey top vapes, the cloud of smoke almost obstructs his face.
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New Study Suggests Vaping Damages Your Immune System

Scientists made mice vape and the damage was even worse than they expected.

Cigarettes have long been recognised as slender harbingers of death and disease – gone are the days of relatives sparking up in the car or movie stars taking a seductive drag on the big screen. In recent years, ciggies have lost their Grease-certified ‘“cool factor” and frankly, it’s hard to find anywhere to legally do it without catching a cold.

Enter the vape, our knight in shining plastic. Vaping has become a favoured (and flavoured) alternative, with many seeing it as the lesser of two evils. Sure, the smell of tobacco won’t cling to your hair like bad BO but, unluckily for the vapour junkies, evidence is piling up that electronic cigarettes may be just as damaging. A new study has found that vaping causes significant cellular and molecular changes in mice - especially in their lungs. 


Originally developed in the late 00s as a tool to help wean smokers off the hundreds of carcinogens in a typical cigarette, e-cigarettes work by delivering nicotine to the brain via fewer chemical toxins – in true faux-ciggie fashion. For many that’s exactly what it does, but instead of just helping to end tobacco use, vaping has spread like a wildfire with young folks. People who shudder at the idea of a morning cig are now vaping before they’ve had their morning coffee and, even worse, many were never smokers to begin with. 

Millions of people now use vape products daily, but because there’s hardly any research on the health impact of inhaling these aerosols, scientists still don’t know much about the long-term effects on the human body.

Carolyn Baglole, co-author of the latest study and associate professor at Montreal’s McGill University, tells VICE that to address some of those gaps her team studied how eight to 12-week-old mice were affected by vaping, when exposed to it three times a day over a four-week period. 


Sadly for Baglole’s mice, they had to do without the fun of shopping for their own aesthetically-pleasing disposable elf bars or shisha vape pens. Instead they were given Juul pods, largely considered the OG sleek vape brand (now somewhat of a relic) and almost singularly responsible for promoting e-cigarettes to teens and younger audiences – a seemingly intentional move. “Juul was the obvious choice because of how popular it became so quickly, particularly with young people,” Baglole tells VICE. 

It was the mass consumption of Juul that prompted former U.S. Surgeon General Jerome Adams to declare youth vaping a national epidemic in 2018. As one Juul pod is nearly equivalent to a 20-pack of cigarettes, he said vape products put children’s health at risk and exposes them to other kinds of addictions, too. In 2022, the U.S. Food and Drug Administration even tried to ban Juul products from the market, albeit temporarily. 


The second of two vaping-related studies published by Baglole’s team in less than a year, this study attempts to replicate human exposure by exposing male and female mice to Juul vapour. The mice were hotboxed with one group experiencing a Juul smoke regime of three 20-minute puff exposures per day, for four weeks. They were given one puff per minute, with about three hours in between each session - a routine designed to mimic the habits of light and moderate Juul users. There were also two control groups - to help determine if it really was Juul causing the changes - who were exposed to either a control liquid or standard room air.

While breathing in mango-flavoured Juul smoke all month might sound like someone’s idea of a good time, that length of exposure to mice is equal to roughly three human years. This is why mice are so perfect to study long-term health consequences – they allow us a glimpse into our futures. What researchers found set off even more alarm bells than they expected, says Baglole. 

“We were quite surprised to see so many different changes,” she says, adding that few papers have actually investigated whether e-cigarettes cause massive molecular change. Supporting what little human research has already been done, this team’s study demonstrates that even low, repeated exposure to vape smoke can impact the lungs at a cellular and molecular level. 

“Even if we don't see massive damage to the lungs, we see pretty substantial changes that could indicate damage in the future,” Baglole says. The bodies of the hotboxed mice show evidence of lung inflammation and molecular damage, meaning the smoke changed the way information was “read” from their DNA.


One of the study’s biggest findings was an increase in the mice’s lung neutrophils, too, AKA white blood cells that fight off infection, AKA the immune system. While you might imagine more white blood cells are good for the body, Baglole says vaping could be causing a chain reaction that scientists can’t see – where smoke triggers an alarm signal to the body, asking the immune system forces for help against potential danger. 

This means that vaping makes the body more vulnerable to developing inflammatory or autoimmune diseases – like pulmonary fibrosis or lupus – and puts vapers at a higher risk of chronic lung disease or certain lung cancers.

Who knows, maybe the multiple vicious flus you caught this winter can be blamed on your vaping habits, rather than the commonly attributed years of lockdowns? 

Laura Crotty Alexander, an associate professor in medicine at University of California San Diego and expert in pulmonology (respiratory medicine), says the study backs her own research up, too. She’s been conducting e-cigarette experiments since 2013 and says the data implies that if a human who vapes were to get bacterial pneumonia, they’d likely respond more severely than someone who doesn’t vape. The same could be said for having worse COVID-19 symptoms – the FDA might’ve publicly rescinded claims they made about this early on in the pandemic, but that was likely a case of unsubstantial evidence.


“Any change in the immune state of a lung is highly concerning because it tells you that the lung is going to respond differently when it has other challenges,” says Crotty Alexander. Dealing with these complications can take a toll on both patients and their doctors, she says, as it’s hard to convince people to take these warnings seriously – before it’s too late.

It’s clear from Baglole’s experiment that Juul altered the mice’s pulmonary immune landscape, but she says more research is needed to truly confirm the human implications. Basically, this study is even more proof of what many anti-smoking campaigns already suspect: Any kind of smoking is harmful. While the physiology of mice lungs are fundamentally different from humans, Baglole believes scientists might find “similar molecular and immunological change” in our own bodies if the study was replicated on humans. 

What now, then? Could this be the news die-hard fans need to throw down those decay-filled contraptions? For some it’s not so simple, but Baglole says you should “make every attempt to eliminate these types of exposures”. If you’re deciding between tobacco or vaping, though, it might be better to stick to the devil we know less about.

Crotty Alexander agrees: “I still think vaping is the lesser of two evils, but it's more evil than I thought it would be.”

Juul Labs did not respond to a request for comment about the research.