Since they hit the market, e-cigarettes have been touted as a safe alternative to tobacco cigarettes for adult smokers.
When research began to suggest otherwise, many questioned whether smoking was still to blame for adverse effects, since most vapers are either “dual users” who also smoke cigarettes or have a prior history of smoking.
Now, a team of researchers at the Keck School of Medicine of USC has demonstrated that – independent of the effects of prior smoking – using e-cigarettes is linked to adverse biological changes that can cause disease. The study, published in Scientific Reports, revealed that vapers experience a similar pattern of changes to gene regulation as smokers do, although the changes are more extensive in people who smoke.
Isolating the effects of vaping from smoking
The researchers recruited a diverse group of 82 healthy adults and separated them into three categories: current vapers, with and without a prior history of smoking; people who exclusively smoke cigarettes; and a control group of never-smokers and never-vapers. They conducted comprehensive in-person interviews to get a detailed vaping and smoking history from each participant. The team verified the histories by performing biochemical analyses on the participants’ blood to measure the concentration of cotinine, a breakdown product of nicotine.
Using next generation sequencing and bioinformatic data analysis, researchers then conducted a genome-wide search for changes in gene regulation in the blood cells of each of the participants. When the normal regulation of genes is disrupted and genes become dysregulated, that dysregulation can interfere with gene function, leading to disease.
For current vapers, they further performed computational modeling to determine whether the detected gene dysregulation was associated with the intensity and duration of their current vaping or the intensity and duration of their past smoking.
“We found that more than 80% of gene dysregulation in vapers correlated with the intensity and duration of current vaping,” said Besaratinia. “Whereas none of the detected gene dysregulation in vapers correlated to their prior smoking intensity or duration.”
Effects of vaping mirror those of smoking
In previous research, Besaratinia and his team have shown that e-cigarette users develop some of the same cancer-related molecular changes in oral tissue as cigarette smokers. They also discovered vapers had the same kind of cancer-linked chemical changes to their genome as smokers.
Tommasi, S., et al. – Keck School of Medicine of USC – 2021-11-24.
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