Findings on e-cigarette flavors and their implications for human health: a systematic review

Objectives This systematic review evaluated the scientific evidence on the effects of flavors in electronic cigarettes in animal models and their impact on human health, aiming to understand the potential risks associated with their use. Methods A PubMed search was conducted using MeSH terms such as “e-cigarettes AND flavor AND nicotine AND e-liquid AND cytotoxicity AND cellular damage and health AND adolescent AND young people.” We selected original studies that evaluated tissue damage, inflammation, oxidative stress, and DNA damage in animal models, as well as health outcomes in humans. In vitro studies, studies with conflicts of interest related to the tobacco industry, and studies that did not meet our objectives were excluded. Results Fruity, menthol/mint, and sweet flavors increase nicotine consumption and preference for e-cigarettes in animal models and are also linked to inflammation, cellular damage, and cardiovascular changes. In humans, these flavors have been associated with respiratory symptoms, reduced lung function, and DNA damage in oral cells. Neurological effects, such as activation of reward circuits, have also been observed. Conclusion The evidence available to date suggests that these products can be as harmful to health as combustible cigarettes. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420261346170 .