Smoking e-cigarettes could disrupt the lungs' ability to fight off infection, even if a vaping product contains no nicotine, according to a study published Sept. 4 in The Journal of Clinical Investigation.
To conduct the study, researchers exposed four groups of mice to e-cigarette vapors containing nicotine, vapors with only solvents but no nicotine, tobacco smoke and clean air, respectively. They later compared results among the four groups.
The mice exposed to cigarette smoke had damaged lungs and emphysema-like inflammation, as expected. Surprisingly, however, the researchers also found lung damage in mice exposed to nicotine-free e-cigarettes, which contained two solvents usually considered a safer alternative to nicotine. The mice in this group did not have inflammation; instead, they had a buildup of fats that disrupted their lungs' normal functioning.
When the mice were exposed to influenza virus, they struggled to fight off the infection, suggesting e-cigarettes increase people's susceptibility to diseases regardless of nicotine content.