In analyzing epithelial cells taken from the mouths of vapers, smokers and people who had never vaped or smoked, researchers found that vapers and smokers had more than twice the amount of DNA damage as found in non-users.
Those who vaped or smoked more frequently had higher DNA damage.
Epithelial cells line the mouth. DNA damage is an early change associated with an increased risk for cancer and inflammatory diseases.
“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 senior study author Ahmad Besaratinia. He is a professor of research population and public health sciences at the Keck School of Medicine in Los Angeles.
“The same pattern held up in smokers,” Besaratinia said in a school news release.
In the study, the researchers recruited 72 healthy adults who were interviewed and underwent biochemical testing.
The study participants were divided into three groups: vapers who had never smoked cigarettes; smokers who had never vaped; and people with no history of smoking or vaping.
The researchers also collected data on how often, and for how long, participants had smoked or vaped. They asked vapers what devices and flavors they used.
The investigators then 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.
These tests showed similar levels of DNA damage between vapers and smokers: 2.6 times and 2.2 times that of non-users, respectively.
The most popular products, including flavored vapes, also appear to be the most harmful.
“The devices and flavors 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,” Besaratinia said. “Clearly these results have significant implications, both for public health and regulatory agencies.”
The new study builds on earlier research that found vaping was linked to alterations in gene expression, epigenetic changes and other biological changes that could foster disease.
About 10% of U.S. teens and more than 3% of adults regularly use e-cigarettes.
Vapers are difficult to study because many have a history of cigarette smoking or are dual users.
“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,” Besaratinia said.
The research team now plans to replicate the findings in a larger group of participants and to study other biological effects resulting from DNA damage that are even more closely related to the onset of chronic disease.
The findings were published Feb. 14 in the journal Nicotine & Tobacco Research.
The study was supported by the U.S. National Cancer Institute, the National Institute of Dental and Craniofacial Research, and the University of California Tobacco-Related Disease Research Program.
The U.S. Centers for Disease Control and Prevention has more on e-cigarettes.
SOURCE: Keck School of Medicine of USC, news release, Feb. 13, 2023
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