Vaping mice study reveals that e-cigarettes hurt lungs and raise infection risk
Scientists who used mice to investigate the health impacts of vaping have made some troubling discoveries, according to a study published on Wednesday.
Researchers from Baylor College of Medicine in Houston, Texas, found that prolonged exposure to e-cigarette vapor hurts normal lung functioning and makes it tougher for mice to fight off viral infections. Those harmful impacts occurred even in mice that were not exposed to nicotine, and were instead exposed only to the supposedly safe solvents used in e-cigarettes, according to a news release from the school.
The study shows further investigation is needed to understand “the effects the allegedly safe-to-use solvents in e-cigarettes have on people,” the researchers said. Their findings were published in the Journal of Clinical Investigation.
“E-cigarettes currently are the most commonly consumed tobacco substitute in the adolescent population,” corresponding author Dr. Farrah Kheradmand, a pulmonologist and professor at Baylor College of Medicine, said in a statement released by the school. “More than 3 million high school age adolescents as well as about 10 million adults in the U.S. are active users.”
Researchers said that “some e-cigarette-related studies have reported negative effects of vaping on health, while other reports stand for the safety of the products when compared to tobacco cigarettes.”
To complete the study, the researchers split the mice into four groups — the first exposed to tobacco smoke, the second to vapors with nicotine and e-cigarette solvents, the third to vapors with solvents but no nicotine and the last to just clean air.
Some results in the Baylor study were expected: For example, the mice exposed to four months of tobacco smoke proved more likely to develop emphysema-like symptoms, severely damaged lungs and inflammation, according to the researchers.
But researchers said the study also “unexpectedly” revealed that “e-cigarette vapors made of propylene glycol and vegetable glycerin solvents only (no nicotine), which are currently considered to be safe solvents, also damaged the lungs. In this case, the researchers did not observe inflammation and emphysema; instead, they found evidence of abnormal buildup of lipids (fats) in the lungs that disrupted both normal lung structure and function.”
Kheradmand said the experiment showed that even without nicotine, inhaling e-cigarette vapor over time “reduces the ability of resident immune cells to respond to infection, increasing the susceptibility to diseases such as influenza.”
The Baylor researchers’ findings come amid growing health concerns around vaping and e-cigarettes in the United States, as health officials in Oregon and Illinois investigate suspected vaping-linked lung illness deaths. More than 200 cases of vaping-related illnesses have appeared recently across roughly 25 states, largely in teenagers and young people, Oregon health officials said in announcing the investigation into the recent death.
Symptoms of the illness include shortness of breath, chest pain, fatigue, vomiting, diarrhea and cough — and though the U.S. Centers for Disease Control and Prevention has not named a cause of the outbreak, each sufferer had vaped before falling ill, Oregon officials said.
“We don’t yet know the exact cause of these illnesses — whether they’re caused by contaminants, ingredients in the liquid or something else, such as the device itself,” Dr. Ann Thomas, public health physician at OHA’s Public Health Division, said in a statement Tuesday.
Nicotine and marijuana can both be vaped, but nearly all of the three dozen vaping-linked illnesses reported recently in Wisconsin were tied to THC products, according to the Associated Press. The Oregon death was also linked to an e-cigarette purchased at a cannabis dispensary, state officials said.
This story was originally published September 4, 2019 at 4:42 PM with the headline "Vaping mice study reveals that e-cigarettes hurt lungs and raise infection risk."
