Menthol in e-cigs could hurt lungs, UH research finds

University of Hawaiʻi at Mānoa

Contact:

Virtual media availability with UH Mānoa professor Yi Zuo on Sunday, August 7, 10-11 a.m. (Hawaiʻi Standard Time). Contact Marc Arakaki at [email protected] or 808-228-3215 to schedule.

Menthol in e-cigarettes may be harmful to respiratory health, according to new research by a team of University of Hawaiʻi at Mānoa experts. The findings come as e-cigarette use is on the rise among Hawaiʻi's youth.

Yi Zuo, UH Mānoa professor of mechanical engineering and adjunct professor of pediatrics, has invented a groundbreaking method that allows the study of the health impact of e-cigarette aerosols. This breakthrough research was published in June 2022 in the American Journal of Physiology-Lung Cellular and Molecular Physiology, "Menthol in Electronic Cigarettes Causes Biophysical Inhibition of Pulmonary Surfactant."

Zuo's research found that flavorings used in e-cigarettes, especially menthol, impaired a lipid-protein film at the air-water surface of the lung. This film is called the lung surfactant. It plays a central role in maintaining the normal respiratory mechanics of the lung. Therefore, Zuo's research indicated that menthol in e-cigarette aerosols may cause an adverse impact on the respiratory health of the user.

"E-cigarettes were initially advertised as a healthier and safer alternative to conventional tobacco smoking when they first appeared in the mid-2000s," Zuo said. "However, increasing research evidence, especially long-term (more than 10 years) toxicological data that emerged only in recent years, has suggested that e-cigarettes are not as safe as originally promised."

E-cigarette use is on the rise among Hawaiʻi's youth, according to a Youth Behavior Risk Survey by the UH Mānoa College of Education. Survey respondents who reported they used an e-cigarette or vaping product at least one day during the previous 30 days before taking the survey increased from 25.1% to 30.6% from 2015 to 2019. Respondents who used vapor products for more than 20 days in the past 30 days before taking the survey increased from 3.6% in 2015 to 10.4% in 2019.

Flavor is a main attraction to e-cigarette users, especially youth. As of 2018, there were more than 15,000 different e-cigarette flavor blends available on the market. Although most flavorings used in e-cigarettes are food-grade additives and scents, their safety and health impact on the respiratory system, at levels inhaled by e-cigarette users, have been largely unknown, until now.

Menthol is a substance found in peppermint, spearmint and other mint plants. It gives a cooling and soothing sensation, and is used to relieve minor pain and irritation. Menthol is added to products as a flavoring including cough drops, beverages, gum and candy. However, none of these products are smoked or inhaled when used. E-cigarette companies, contrastingly, add menthol to their products to make them more appealing and seemingly less harmful when used.

Zuo hopes this research finding may contribute to a better understanding of the health impact of e-cigarettes, especially on youth, and a better regulation of e-cigarette products. This research was a collaborative effort between Zuo's lab and Professors Ellinor Haglund and Rui Sun in the UH Mānoa Department of Chemistry. This research was supported by a National Science Foundation award and the George F. Straub Trust and Robert C. Perry Fund of the Hawaiʻi Community Foundation.

Other stories from UH News involving e-cigarettes:

Public link

Please use the above public link if you want to share this noodl on another website.