Electronic cigarettes alter the inflammatory state of the brain, heart, lungs and colon
Newswise – Researchers at the University of California, San Diego School of Medicine report that daily use of pod e-cigarettes alters the inflammatory state of multiple organ systems, including the brain, heart, lungs, and lungs. colon. Effects also vary depending on the flavor of the e-cigarette and may influence how organs respond to infections, such as SARS-CoV-2.
The study, published on April 12, 2022 in the journal eLifeis the first to review JUUL devices and their flavoring agents in a multi-organ fashion.
“These pod-based e-cigarettes have only become popular in the past five years or so, so we don’t know much about their long-term health effects,” said Laura Crotty Alexander, MD, professor Fellow of Medicine at UC San Diego School of Medicine and Section Chief of Pulmonary Critical Care at San Diego Veterans Health System.
More than 12 million adults in the United States currently use e-cigarettes, with the highest usage rates among 18-24 year olds. Despite their popularity, research on e-cigarettes has largely been limited to short-term use studies, older devices, such as vape pens or box mods, and e-liquids with concentrations of nicotine significantly lower than those of modern systems based on refillable pods.
Crotty Alexander’s team focused on today’s hottest e-cigarette brand, JUUL, and its most popular flavors: mint and mango. To model chronic e-cigarette use, young adult mice were exposed to flavored JUUL aerosols three times daily for three months. The researchers then looked for signs of inflammation throughout the body.
The authors saw the most striking effects in the brain, where several inflammatory markers were elevated. Additional changes in neuroinflammatory gene expression were noted in the nucleus accumbens, a brain region critical for motivation and reward processing. The findings raise major concerns, they said, because neuroinflammation in this region has been linked to anxiety, depression and addictive behaviors, which could further exacerbate substance use and addiction.
“Many JUUL users are teenagers or young adults whose brains are still developing, so it’s pretty terrifying to learn what may be going on in their brain considering how it could affect their mental health and their behavior,” Crotty Alexander said.
Inflammatory gene expression also increased in the colon, particularly after a month of e-cigarette exposure, which may increase the risk of gastrointestinal disease. In contrast, the heart showed decreased levels of inflammatory markers. The authors said this state of immunosuppression could make heart tissue more vulnerable to infection.
While the lungs did not show signs of tissue-level inflammation, numerous gene expression changes were observed in the samples, calling for further study of the long-term effects of pod e-cigarettes on lung health.
The researchers also found that each organ’s inflammatory response varied depending on the JUUL flavor used. For example, the hearts of mice that inhaled mint aerosols were significantly more susceptible to the effects of bacterial pneumonia than those that inhaled mango aerosols.
“It was a real surprise for us,” Crotty Alexander said. “This shows us that chemical flavorings themselves also cause pathological changes. If someone who frequently uses menthol-flavored JUUL e-cigarettes were infected with COVID-19, it’s possible their body would react differently to the menthol. infection.
Each organ has its own finely tuned immune environment, so disrupting this balance through e-cigarette use could lead to numerous long-term health effects, the authors wrote.
“It’s clear that every e-cigarette device and flavor needs to be studied to determine how it affects health throughout the body,” Crotty Alexander said.
Co-authors include: Alex Moshensky, Cameron S. Brand, John Shin, Jorge A. Masso-Silva, Ira Advani, Deepti Gunge, Aditi Sharma, Sagar Mehta, Arya Jahan, Sedtavut Nilaad, Jarod Olay, Wanjun Gu, Tatum S Simonson, Josephine Pham, Samantha Perera, Kenneth Park, Rita Al-Kolla, Hoyoung Moon, Soumita Das, Min Kwang Byun and Joan Heller Brown, all at UC San Diego, as well as Hasan Alhaddad, Daniyah Almarghalani, Zahoor Shah and Youssef Sari at the University of Toledo.
This work was supported, in part, by the National Institutes of Health (grants R01HL137052, R01HL145459, T32HL007444), American Heart Association (grants 16BGIA27790079, 19POST34430051), ATS Foundation Award for Outstanding Early Career Investigators, VA Merit Award (1I01BX004767), the Tobacco Disease Research Program (T30IP0965, 26IP-0040, 28IP-0024), and UC San Diego (grant RS169R).