Chinese Research Team Finds: E-cigarettes have less impact on respiratory system than traditional cigarettes

On October 8, 2022, the School of Pharmacy at Sun Yat-Sen University published a paper in the global core toxicology journal “Archives of Toxicology,” which stated that under the same nicotine dosage, the harm of e-cigarette aerosol to the respiratory system is less than that of traditional cigarette smoke.

In recent years, the impact of e-cigarettes and traditional cigarettes on health has been a hotly debated issue in the field of public health. In this study, the research team at Sun Yat-Sen University compared the differences and similarities of the effects of traditional cigarettes and e-cigarettes on mouse lung function, inflammatory factors, and protein expression under the same nicotine content, filling the gaps in related scientific research.

The researchers used RELX YK watermelon-flavored e-cigarettes and a certain brand of traditional cigarettes as samples, randomly dividing 32 mice into four groups, respectively exposing them to clean air, low-dose e-cigarette aerosol, high-dose e-cigarette aerosol and traditional cigarette smoke for 10 weeks, and analyzed multiple indicators.

Pathological section results of lung tissue showed that the lung coefficient of mice exposed to traditional cigarettes was significantly increased, and the shape of the trachea changed, suggesting that there may be lesions in the respiratory system. In contrast, the lung coefficient of mice exposed to e-cigarettes did not change significantly, and the shape of the trachea did not change.

Lung function tests found that exposure to traditional cigarettes led to significant abnormalities in several lung function indicators in mice, but the e-cigarette group had only one indicator that decreased. At the same time, pathological results showed that both traditional cigarettes and e-cigarettes may cause abnormalities in the mouse lungs, but the damage caused by traditional cigarettes was more obvious.

Serum inflammatory factor detection and transmission electron microscopy found that both traditional cigarettes and e-cigarettes can cause airway inflammation, but the extent of harm caused by traditional cigarettes is greater. Even at a nicotine content twice that of traditional cigarettes, e-cigarettes caused smaller pathological damage to the mouse trachea.

Finally, the researchers also conducted proteomic analysis of mouse lung tissue. The results showed that the difference in protein changes caused by traditional cigarettes was more concentrated in inflammation-related pathways, while the abnormal expression caused by e-cigarettes was less, and the impact on the inflammation signal pathway was smaller.

The researchers stated that the research results clearly show that exposure to traditional cigarettes and e-cigarettes with larger inhalation doses can be harmful to the respiratory system. However, under the same nicotine dosage, the harm of e-cigarette aerosol to the respiratory system is less than that of traditional cigarette smoke.

Since e-cigarettes do not need to be burned, they do not produce tar, which is why they are generally regarded as a reduced-harm substitute by the medical community. The Centers for Disease Control and Prevention (CDC) in the United States clearly stated on its official website that switching from traditional cigarettes or other combustible tobacco products to e-cigarettes may have potential benefits for non-pregnant adult smokers.

However, due to the short time since their appearance, research on e-cigarettes is not yet sufficient. In recent years, many scientific research institutions and public health organizations have focused on the potential impact of e-cigarettes.

In January 2022, researchers from the US Food and Drug Administration (FDA) published a paper in “Tobacco Control” which stated that e-cigarettes were less harmful than traditional cigarettes. For smokers who switch to e-cigarettes, the levels of biomarkers of various carcinogens in their urine will be reduced, up to 95%.

In September 2022, the UK Department of Health and Social Care released the “Eighth Independent Report on Nicotine E-Cigarette Research,” which stated that compared with traditional cigarettes, e-cigarettes significantly reduced exposure to harmful substances, and could significantly reduce biomarkers related to cancer, respiratory and cardiovascular diseases.

The research team at Sun Yat-Sen University stated that this study comprehensively and systematically analyzed the relative safety of e-cigarettes at the animal level, and hopes to conduct more clinical research in the future to objectively and thoroughly evaluate the long-term effects of e-cigarettes.