• A University of Southern California study has found that vapers exhibit similar chemical modifications to people who smoke cigarettes – modifications commonly found in nearly all types of human cancer.
• In an email sent to BI, the study’s lead researcher, Ahmad Besaratinia, said the study “demonstrates, for the first time, biologically important molecular changes in blood cells of vapers, similarly to smokers.”
• Experts told BI that research into the physiological effects of vaping is often hindered by the fact that many vapers have a history of smoking.
• Though the USC study seems to have avoided this hindrance, the fact many vapers are ex-smokers may make research into vaping’s physiological impact challenging.
• 6.1% of British vapers in the period January 2019 to September 2019 had never smoked, according to UK government research, while a 2018 study found that 15% of US adult vapers had never smoked.
• Visit Business Insider’s homepage for more stories.

A University of Southern California study published in February found vapers exhibit similar DNA changes to people who smoke cigarettes – modifications commonly found in nearly all types of cancer.

The study examined the blood of a group of people, controlled for age, gender, and race, who were split equally into three categories. These were people who only vape; people who only smoke; and a control group of people who neither vape nor smoke.

The study also said the specific chemical alterations found – known as “epigenetic changes” – can cause genes to malfunction, and are commonly found in nearly all types of human cancer.

In an email sent to Business Insider, the study’s lead researcher, Ahmad Besaratinia, said the research “demonstrates, for the first time, biologically important molecular changes in blood cells of vapers, similarly to smokers.”

If the study’s findings are corroborated elsewhere, it could seriously damage a vaping industry already facing severe criticism and regulatory action.

But experts told Business Insider that widespread corroboration of the study’s findings may prove tricky for one simple reason. This is the fact many vapers are ex-smokers.

The USC study doesn’t appear to be hampered in this way. Berasantinia said most vapers in the study were never smokers, and the few who had a brief history of smoking had their last cigarette, on average, 3.5 years prior to participating in the study. But the experts said vaping research is often held back by many vapers’ history of traditional smoking.

As such, it’s often hard to prove health issues found in vapers are actually caused by their vaping.

Barnaby Page, an analyst at vaping-focused market research firm ECigIntelligence, said: “The majority of vapers are ex-smokers, smoking can induce changes in DNA methylation that last long after the person has quit smoking. This is a pretty common problem in research on vaping.”

Page’s point was reiterated by Alan Boobis, an emeritus professor of toxicology at Imperial College London, who said it’s “almost always an uncertainty in studies in vapers, that the effects were caused by their history of smoking.”

“There is good evidence to show that vapers tend to be more dependent – i.e., smoke more heavily, which is the reason why they have not stopped smoking without support,” added Lion Shahab, an associate professor in health psychology at UCL.

These claims seem borne out by the stats. Just 6.1% of British vapers in the period January 2019 to September 2019 had never smoked, according to UK government research, while a 2018 study in the Annals of Internal Medicine academic journal found that just 15% of US adult vapers had never smoked.

Yet – where vaping was once viewed as a fairly benign alternative to smoking – this issue with much vaping research hasn’t held back regulators from taking stringent anti-vaping measures.

Major e-cigarette maker Juul and its vaping industry peers must submit applications to the FDA by May 12 that make the case for their to stay on the market.

It’s a seminal moment for both the FDA and e-cigarette companies, especially Juul, which values itself at $20 billion but has an official valuation of more like $12 billion.

In 2017, the FDA launched an undercover crackdown on Juul sales to minors, which it said was the “largest coordinated enforcement effort” in agency history. As part of these efforts, it issued more than 1,300 warning letters and fines to retailers for illegally selling Juuls and other e-cigarette products to minors.