Australian scientific review finds vaping likely causes cancer
A first-of-its-kind scientific review has found that vaping is likely to cause cancer; This contradicts claims that it is safer than smoking and underscores the urgency of efforts to stop young people getting addicted.
Experts have long warned that the chemicals inhaled from e-cigarettes are carcinogenic and harmful to human health, but a definitive link between e-cigarettes and cancer has not yet been established.
E-cigarette devices have emerged too recently for scientists to study cancer risk through decades of epidemiological studies; with exposure to carcinogenic substances Cancer diagnosis can take 10 to 30 years.
But in the absence of long-term studies on e-cigarette use, Australian scientists explored existing evidence on e-cigarette vapor, which includes laboratory studies, animal experiments and studies of biomarkers in the blood and urine of people who vape.
Bernard Stewart, lead author of the review and an adjunct professor at the University of NSW, said that taken together, the evidence led them to their most definitive conclusion yet, that “e-cigarettes are likely to cause mouth and lung cancer”.
“Vaping should be avoided as it poses a danger in itself,” said Stewart, a prominent cancer researcher. “This is not an alternative to smoking, it is not an alternative to illegal drugs… it is dangerous and that is the message.”
The review cites the case of a 19-year-old man who vaped heavily and died of treatment-resistant oral squamous cell carcinoma. Given the man had no other risk factors, the researchers found vaping reasonable. may be a factor at his death.
Chemicals shown to pass into the body from e-cigarettes include nicotine derivatives that can trigger tumors, toxic chemicals such as nickel, volatile organic compounds and cytotoxic sweeteners.
Stewart said studies have shown that these chemicals cause oxidative stress, inflammation and genomic damage in tissues, and they are known as precursors to cancer. He said experiments on e-cigarette aerosols clearly show DNA damage and long-term changes in mouth and lung tissue that indicate the development of cancer.
“One specific study stands out in which mice exposed to aerosols from e-cigarettes through inhalation developed lung cancer,” Stewart said.
“Not all of them, of course, but they were significantly more than the corresponding controls and also developed changes consistent with the eventual development of cancer in the bladder.”
Many studies treat e-cigarettes as a gateway to smoking rather than dangerous in themselves, and many compare e-cigarettes to the known evils of smoking. Initially, electronic cigarettes were marketed as a safer alternative to smoking.
But Steward said pitting the two against each other delays and belittles our understanding of the health effects of vaping, saying it’s like trying to examine the safety of knives by comparing them to machine guns.
“This plays into the hands of tobacco companies, who don’t care whether they make money through e-cigarettes or cigarettes,” he said.
Importation of e-cigarettes has been illegal since January 2024, but disposable e-cigarettes are ubiquitous and can be easily purchased in stores and online.
Distinguished Professor Brian Oliver, a nicotine researcher who studies the effects of e-cigarette smoke on rodents, said studies on rats and mice cannot be directly applied to humans (for example, mice are actually more resistant to cancer than humans). However, they provide important information regarding toxicology and carcinogens, among other evidence.
Oliver said of the new research, in which he was not involved: “I think what they’re saying is probably true.” “There is enough evidence that there are enough ingredients and enough toxic chemicals in e-cigarettes that they should all cause cancer.”
The review was published on: carcinogenesis, It did not attempt to determine how much vaping increases the risk of cancer or compare different types of nicotine e-cigarettes in terms of health risk.
Trying to address these questions with consistent long-term studies would be a “nightmare,” Oliver said, in part because of the multitude of designs and thousands of flavors floating around e-cigarette shops, each with a different chemical profile, from blueberry bliss to English marmalade.
Professor Becky Freeman, from the University of Sydney’s School of Public Health, said long-term smokers who use e-cigarettes through pharmacies should continue to quit smoking.
“This is definitely a good thing to do. We don’t want these people to go back to smoking,” said Freeman, the e-cigarette and tobacco control researcher, adding that cigarettes kill two out of every three people who continue to smoke.
But Freeman hoped the new review would persuade people who have never vaped or smoked to avoid nicotine and help “turn the tide” of vaping addiction for people aged 18 to 24.
Vaping rates in this age group have remained stubborn despite public health campaigns encouraging smoking cessation. According to the Cancer Institute of NSW, one in five people aged 16 to 24 currently use e-cigarettes.
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Angus Dalton is science correspondent for The Sydney Morning Herald.Connect with: X or email.
