Vaping alters thousands of genes, and the type of flavour used appears to be the most significant factor driving these changes, according to new research. The study, published in the journal Frontiers in Oncology, found that people who vape regularly show altered activity in 3,124 genes across the genome compared with non-users.
Flavour and Device Type Matter Most
While some of the genetic changes (28.8%) relate to how often or how much people vape, scientists say two-thirds (66.6%) are linked to the type of flavours and devices they use. This highlights the role of flavour and device type in the biological effects of vaping, which could have implications for future regulations.
Because vapes, or e-cigarettes, are relatively new, their long-term health risks remain unclear. However, changes in expression of disease-related genes can provide early clues about potential harms. Previous research has already shown that vaping is linked to changes in gene expression involved in cancer development, as well as certain heart and lung diseases.
Study Details
Study senior author Professor Ahmad Besaratinia from the University of Southern California's Keck School of Medicine said: “One major question still remains: what is driving these changes? Is it the act of vaping itself - or is it the intensity and duration of vaping, the characteristics of the products used, or some combination of these?”
The research team compared changes in gene expression among 83 people, including vapers, smokers and non-users. They found that two-thirds of changes in gene activity could be explained by vape flavour and device type, suggesting the chemical makeup of vaping products and the design and configuration of devices play a major role in their biological effects.
Among vapers, those who used fruit flavours or multiple flavours, as well as advanced refillable devices (sometimes called “mods”), showed more changes in gene expression compared with other groups. Prof Besaratinia said: “The implication is that each flavour has unique attributes that produce different biological effects. This is something regulators should carefully consider when evaluating the health risks or potential benefits of each flavoured e-cigarette product.”
Gene Expression by Flavour
The analysis showed that different vape flavours produced different changes in gene regulation:
- Sweet flavours: linked to changes in 2.9% of affected genes
- Mint or menthol flavours: linked to changes in 0.9% of affected genes
- Fruit flavours: linked to changes in 31% of affected genes
- Multiple flavours: linked to changes in 64.3% of affected genes
Higher-generation devices, such as mods, were also associated with the strongest and most consistent changes in gene regulation. Prof Besaratinia said: “These product differences explained more of the variation in gene regulation than how much or how often people vaped.”
Disease Risks
The research team conducted a bioinformatics analysis to identify molecular processes and diseases linked to the gene expression changes. Among vapers, cancer was linked to the highest number of gene expression changes, followed by endocrine disorders, gastrointestinal diseases and neurological diseases.
The findings have particular relevance as the US Food and Drug Administration (FDA) finalises official guidance on flavoured e-cigarette products. Prof Besaratinia said: “Regulators have been tasked with verifying that the benefits of using e-cigarettes for adults outweigh the risks posed to youth. But we show here that vaping flavoured products is associated with disease-related molecular changes, regardless of the user’s age.”
The research team recommends regulators evaluate products in a more granular way, with greater attention to flavours and device characteristics. They say mods and other newer devices can deliver higher nicotine levels than earlier-generation vapes and often contain potentially toxic additives designed to make vaping smoother and more appealing.
Prof Besaratinia and his team are now conducting a follow-up study of the chemicals used in vaping liquid to determine which compounds are linked to changes in gene expression. He added: “Once we identify these chemicals, policymakers could instruct manufacturers to either eliminate these chemicals or reduce their level in e-cigarette products to minimise potential harm.”
