Vaping shows comparable DNA damage in oral cells to smoking

Exclusive smokers and exclusive vapers had comparable increases in DNA damage of their oral epithelial cells, according to study results published in Nicotine & Tobacco Research.

Further, heavy smokers or vapers, “pod” users and sweet-flavored e-liquid users had the highest levels of DNA damage compared with nonusers, according to researchers.

“There is a misconception that electronic cigarettes (e-cigarettes) are benign and cause little to no harm,” Ahmad Besaratinia, MPH, PhD, professor in the department of population and public health sciences at the Keck School of Medicine of USC, told Healio. “Our study provides compelling evidence against this misconception; we demonstrate that e-cigarettes are not only not risk-free, but also have comparable DNA-damaging effects to those of tobacco cigarettes. Most importantly, we show that the use of the most popular e-cigarette device type (pod) and e-liquid flavor type (sweet) is associated with the highest levels of DNA damage in vapers.”

Besaratinia and colleagues examined 72 healthy adults matched for age, gender and race and categorized as vapers who never smoked (n = 24), smokers who never vaped (n= 24) or as nonusers (n = 24), to compare their DNA damage in the cells that line the mouth, or oral epithelial cells, using a long-amplicon quantitative polymerase chain reaction assay.

Researchers gathered information on the frequency and length of smoking/e-cigarette use — with minimum use criteria set at 6 months for vapers and 1 year for smokers — as well as the device and flavor of e-liquid that vapers used by having study participants complete questionnaires, interviews and biochemical tests.

Compared with nonusers, researchers found that mean levels of DNA damage increased by 2.6-fold in vapers (P = .005) and by 2.2-fold in smokers (P = .02).

Looking at usage levels and their link to damage, vapers and smokers classified as heavy users had higher DNA-damage levels than light users, signaling a dose-dependent relationship.

Additionally, researchers observed varying damage levels among vapers according to the device type they used. Specifically, those who used “pods” — or fourth-generation devices such as JUUL — showed 3.3-fold greater mean levels of DNA damage, whereas vapers who used “mods,” or third-generation devices, showed a 2.6-fold increase in damage compared with nonusers.

Among users of fruit-, sweet-, mint/menthol-, tobacco- and multiple-flavored e-liquids, users of sweet-flavored e-liquids had the most damage when compared with nonusers (P < .05), according to researchers.

Further, the amount of DNA damage found in exclusive vapers was not related to the e-liquid’s nicotine content, results showed.

“This study demonstrates that relying on measurement of concentrations of a limited number of chemicals in e-cigarette liquid or vapor is not an informative way of evaluating the health effects of vaping,” Besaratinia told Healio. “Chemical analyses of e-cigarette vapor have revealed the presence of some of the same toxicants and carcinogens as those found in cigarette smoke, although mostly at substantially lower levels. E-cigarette vapor also contains chemicals that are not found in cigarette smoke. The reduced levels of toxicants and carcinogens in e-cigarette vapor has led to the perception that e-cigarette use is safe or less harmful than tobacco smoking. While the lower levels of toxicants and carcinogens in e-cigarette vapor may imply a reduced health risk, they cannot, however, equate to no risk.”

Besaratinia told Healio he hopes his findings help protect both adults and teens who vape by raising awareness of the biological consequences of vaping and encouraging further regulation of these products.

“Science-based evaluation of the safety of e-cigarettes and comprehensive health risk analysis of vaping are urgently needed to inform the FDA’s regulation of tobacco products to protect public health,” Besaratinia told Healio. “The findings of our study will guide clinicians and other health professionals in advising the general public on the pros and cons of e-cigarette use (vaping) relative to smoking.”

For more information:

Ahmad Besaratinia, MPH, PhD, can be reached at ahmad.besaratinia@med.usc.edu.

Reference:

• DNA damage levels similar in vapers and smokers, study finds. https://keck.usc.edu/dna-damage-levels-similar-in-vapers-and-smokers-study-finds/. Published Feb. 13, 2023. Accessed Feb. 15, 2023.