Bombshell study finds vaping probably causes two types of cancer

Nicotine-based vapes are likely to increase the risk of cancers affecting the lungs and mouth or throat, Australian researchers have concluded. A team of experts from a range of fields, including pharmacy, epidemiology, thoracic surgery and public health, reviewed evidence from previous studies and laboratory research.

Study leader Professor Bernard Stewart, from the University of New South Wales (UNSW), said: “To our knowledge, this review is the most definitive determination that those who vape are at increased risk of cancer compared to those who don’t. Considering all the findings — from clinical monitoring, animal studies and mechanistic data — e-cigarettes are likely to cause lung cancer and oral cancer.”

E-cigarettes have been hailed as around 95% less harmful than smoking because they deliver nicotine without burning tobacco.

This means they do not produce tar or carbon monoxide, which are two of the most damaging elements in tobacco smoke.

Vaping has been recommended as a tool to help adults quit smoking. However, health experts have stressed that vaping is not harmless, and people who do not smoke should not start vaping.

The researchers noted that colourful, flavoured devices have spread quickly and widely, becoming a common sight outside schools, bars and train stations.

Study co-author Professor Freddy Silas, also of UNSW, said e-cigarettes could also act as a gateway to smoking.

He added: “But the extent to which they may cause cancer in their own right has not received as much attention in research.

“The evidence was remarkably consistent across fields. It dictated an unequivocal finding now, though human studies that estimate the risk will take decades to accumulate.”

The team identified numerous carcinogenic compounds in e-cigarette aerosols, including volatile organic chemicals and metals released from heating coils.

They also examined evidence of biomarkers in people showing DNA damage, oxidative stress and tissue inflammation; experiments in mice that caused lung tumours; and laboratory studies showing cellular damage and disrupted biological pathways linked to cancer.

Writing in the journal Carcinogenesis, the researchers concluded: “Nicotine-based e-cigarettes are likely to be carcinogenic to humans who use them, causing an indeterminate burden of oral cancer and lung cancer.”

The review also included researchers from The University of Queensland, Flinders University and The University of Sydney, and Royal North Shore, The Prince Charles and Sunshine Coast University hospitals.

However, Professor Peter Hajek, director of the Health and Lifestyle Research Unit at Queen Mary University of London, described the review's conclusions as "misleading".

He said: "The authors specify early on that they are not comparing vapers and smokers. This allows them to present a detection of any level of a suspect chemical, however negligible, as ‘carcinogenic’.

"Modern sensitive methods can detect tiny traces of chemicals with no relevance for health, but it is the dose that makes the poison. Higher doses have been reported in studies which fry e-liquid at very high temperatures, but this has nothing to do with how vapers use it."

Prof Hajek said the review failed to acknowledge that vapin exposes users to only a very small fraction of the carcinogens in tobacco smoke.

He added: “The authors also found several case reports of vapers who got cancer, but drinkers of orange juice and cyclists get cancer too; and in addition, most of these cases were long-term smokers before they switched to vaping.

“Misinforming smokers risks discouraging them from using e-cigarettes, which are one of the most effective methods that exist to help people stop smoking.

"Switching from smoking to vaping removes the major source of all smoking related diseases, including cancer.”