Inhaled or Ingested, Which Is Worse, E-Vaping or High-Fat Diet?

Area of Science:

• Biomedical Science
• Toxicology
• Inflammation Research

Background:

• Long-term e-cigarette vaping is linked to inflammation, independent of nicotine.
• High-fat diet (HFD) consumption also causes systemic low-grade inflammation.
• E-cigarette use for weight control is increasing with rising obesity rates.

Purpose of the Study:

• To investigate the inflammatory effects of nicotine-free e-cigarette vapor exposure in mice on a long-term HFD.
• To compare the inflammatory impact of nicotine-free e-vapor versus HFD.
• To identify specific inflammatory markers affected by these exposures.

Main Methods:

• Mice were fed a HFD for 16 weeks.
• During the final 6 weeks, groups were exposed to nicotine-free e-vapor or ambient air.
• Serum, lung, liver, and epididymal fat were analyzed for inflammatory markers.

Main Results:

• Both e-vapor and HFD independently increased serum inflammatory markers (IFN-γ, CX3CL1, IL-10, CCL20, CCL12, CCL5).
• Nicotine-free e-vapor exposure resulted in higher levels of IFN-γ, CX3CL1, and IL-10 compared to HFD alone.
• Epididymal fat mRNA expression mirrored serum inflammatory patterns, suggesting fat tissue as a source.
• No significant changes in lung cytokines were observed.
• The anti-inflammatory cytokine IL-10 increased in the liver when e-vapor and HFD were combined.

Conclusions:

• Short-term nicotine-free e-vapor exposure is more potent in inducing systemic inflammation than long-term HFD consumption.
• The inflammatory response appears to originate from adipose (fat) tissue.
• Further research is required to understand the long-term health consequences of nicotine-free e-cigarettes.