E-cigarette smoke caused lung cancer in mice: Nearly 25%of study animals developed tumors after a year of nicotine ‘vapor’ exposure
- Nine out of 40 mice exposed to a year’s worth of e-cigarette vapor developed cancer
- NYU researchers found nicotine itself may be carcinogenic
- But mice exposed to nicotine free ‘vapor’ did not get lung cancer
Vaping can cause cancer, at least in animals, according to a new study.
Although it was initially billed as a safer alternative to smoking – which causes 160,000 cancer deaths a year in the US – vaping gave nearly a quarter of mice exposed to e-cigarette vapor for a year lung cancer.
E-cigarettes first hit the market about a decade ago, and have since been linked to nearly 20 deaths and over a thousands illnesses in the US, but its too soon for any potential cases of cancer related to the devices to have occurred.
The 40 mice were exposed to far more of the ‘smoke’ than a human would be while vaping, but the New York University (NYU) team says their results capture a process that makes nicotine e-cigs carcinogenic.
However, only one of the 17 animals that were exposed to nicotine-free smoke got cancer, suggesting nicotine itself may be the catalyst for disease.
New research from NYU suggests that e-cigarette smoke does cause lung cancer. The study found the disease in nine out of 40 exposed animals
Teen vaping has been deemed an ‘epidemic’ but US health officials, and we’re only beginning to learn what immediate and long-term consequences the devices might have for the millions of young people using them.
Some 80 percent of the Americans who have developed vaping-related lung injuries are under the age of 35, and 16 percent are teenagers 18 or under.
Deaths have occurred in at least 16 states, with the latest confirmed in Connecticut.
It’s clear the liquids heated by e-cigarettes are doing something potentially life-threatening to the lungs, but scientists have yet to work out exactly what.
Dr Moon-shong Tang at NYU has already begun looking at what might happen to them down the line.
Their previous work, published in 2018, had already demonstrated that e-cigarette vapor could trigger potentially carcinogenic DNA changes in petri dish samples of tissues.
In order to expand on those findings, they exposed 40 mice to high levels of e-cigarette ‘smoke’ for 54 weeks, or just over a year.
They chambers they used were a a bit like a pressure cooker test, in that the mice were surrounded by the vapor, so that their entire bodies might feel the effects.
Indeed they did. nine of the 40 animals developed lung cancers.
But when they put 20 mice through the same paces using nicotine-free e-cig smoke, none of them developed cancer.
Most warnings against smoking cigarettes have focused on the carcinogenic qualities of tobacco and the tiny particles inhaled when smoking a burning cigarette.
The role of nicotine in cancer has been more controversial.
Previous work has found that the processing done to tobacco in preparation to make cigarettes creates two carcinogenic compounds, NNN and NNK, nitrosamines that corrupt DNA and cause cancer.
But Dr Tang’s previous work showed that e-cig smoke and nicotine itself could deposit the same problematic molecules as well as further encouraging DNA changes key to cancer development.
‘Our results support the argument that the nicotine-derived DNA adducts are likely the main causes for carcinogenesis in mice exposed to E-cig smoke,’ said Dr Tang’s co-author, Dr Herbert Lepor, a urologist at NYU.
That was further confirmed by the absence of lung cancers in the nice exposed to nicotine-free vapor.
‘Our next step in this line of work will be to expand the number of mice studied, to shorten and prolong E-cigarette exposure time, and to further investigate the genetic changes caused by E-cigarette smoke,’ Dr Lepor added.
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