Both, smokers and vapers, suffer similar level of DNA damage: Study

Scientists have found that vapers and smokers have similar levels of DNA damage, which is more than twice the amount found in non-users, according to a new study.

According to the study, DNA damage was higher among those who vaped or smoked more frequently. It was also higher in vapers who used vape pods and mods, as well as sweet-, fruit- or mint-flavoured vapes, it said.

A group of researchers from the Keck School of Medicine of University of Southern California (USC), US, analysed epithelial cells taken from the mouths of vapers, smokers, and people who had never vaped or smoked, the study said.

E-cigarettes, used regularly by more than 10 per cent of US teens and more than 3 per cent of adults, were once pitched as a healthy alternative to tobacco cigarettes.

But research increasingly links the use of e-cigarettes, or vaping, to many of the same life-threatening diseases that plague smokers, the study published in the journal Nicotine & Tobacco Research said.

"For the first time, we showed that the more vapers used e-cigarettes, and the longer they used them, the more DNA damage occurred in their oral cells," said Ahmad Besaratinia, professor at the Keck School of Medicine and the study's senior author.

"The same pattern held up in smokers," said Besaratinia.

The study showed similar levels of DNA damage between vapers and smokers: 2.6 times and 2.2 times that of non-users, respectively, it said.

In terms of devices, vapers who used pods had the highest levels of DNA damage, followed by those who used mods. In terms of flavours, sweet-flavoured vapes were linked to the highest levels of DNA damage, followed by mint/menthol- and fruit-flavoured vapes, the study said.

The most popular products, including flavoured vapes, used by about 85 per cent of teens who vape, also appear to be the most harmful, in terms of producing DNA damage, the study said.

DNA damage to oral epithelial cells, which line the mouth, is an early change that is associated with an increased risk for many types of chronic disease, including cancer and inflammatory diseases, the study said.

The study is the first to clearly distinguish between the DNA damage that occurs in exclusive vapers versus smokers and to provide details about the risks vapers face based on how often they vape and what devices and flavours they use, it said.

Vapers are difficult to study because they typically have a history of cigarette smoking or are dual users, who both vape and smoke tobacco cigarettes, the study said.

"We designed our study to tease out the effects of vaping in e-cigarette users who were neither cigarette smokers nor dual users at any point in their lives," said Besaratinia.

"The devices and flavours that are most popular and highly consumed by youth vapers, as well as adults, are the ones that are associated with the most DNA damage," said Besaratinia.

According to the study, the researchers recruited 72 healthy adults and split them into three groups, matched for age, race and gender: current vapers (who had never smoked), current smokers (who had never vaped) and people with no history of smoking or vaping.

They verified the history of each participant using detailed questionnaires, interviews and biochemical tests to ensure that any observed effects could be directly linked to either vaping or smoking, the study said.

Besaratinia and his team also collected data on how often, and for how long, participants had smoked or vaped, and in the case of vaping, what devices and flavours they used, the study said.

Then, they collected a sample of epithelial cells from each participant's mouth and tested for damage to specific genes known to indicate assault to the genome, the study said.

"Clearly these results have significant implications, both for public health and regulatory agencies," said Besaratinia.