Vaping of electronic cigarettes (e-cigarettes) has increased dramatically over the past decade. Vaping is often marketed as a safer alternative to traditional tobacco smoking. While e-cigarettes are perceived to pose fewer respiratory and cardiovascular risks than conventional cigarettes, growing evidence suggests they may have adverse effects on cognitive functions, particularly memory and learning. Health-care workers should be aware the impact of e-cigarette exposure on cognition and the associated mechanisms.
Recent studies in animals demonstrate that e-cigarette exposure can impair cognitive performance. For example, mice exposed to e-cigarette aerosols for short durations exhibited deficits in tasks that require memory and learning, such as novel object recognition and maze navigation tests. These findings suggest that even brief exposure to e-cigarette vapor can disrupt hippocampal-dependent cognitive processes, highlighting the potential risks of these products to brain health.1,2 (The hippocampus is often referred to as the brain's librarian. While physical libraries may be becoming less common, we must ensure that our brains don’t follow the same path.)
Understanding cognitive changes with vaping
One proposed mechanism for these cognitive changes is neuroinflammation. E-cigarette vapor contains numerous chemicals, including nicotine, flavoring agents, and byproducts of heating such as formaldehyde and acetaldehyde. These compounds can activate microglia—the brain's resident immune cells—leading to the release of proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Chronic neuroinflammation is a well-known contributor to cognitive decline, particularly in conditions like Alzheimer’s disease.3
Additionally, oxidative stress appears to play a significant role in the cognitive effects of e-cigarettes. The production of reactive oxygen species (ROS) during vapor inhalation can overwhelm the brain's antioxidant defenses and lead to neuronal damage. Oxidative stress is particularly damaging to the hippocampus, where high metabolic activity renders neurons especially vulnerable to oxidative damage.4
Nicotine, a primary component of most e-cigarette formulations, has complex effects on the brain. While nicotine can transiently enhance attention and working memory, its chronic exposure disrupts normal acetylcholine signaling, potentially impairing long-term cognitive functions. In young users whose brains are still developing, the impact of nicotine may be even more pronounced, raising concerns about the long-term cognitive risks for adolescents who use e-cigarettes.5-7
Research on e-cigarette users reports reduced attention spans, increased susceptibility to cognitive errors, and impaired memory recall compared to nonusers. While these studies face challenges in isolating e-cigarette effects from confounding factors such as prior smoking history or polysubstance use, the consistency of results between animal studies and human studies highlights the plausibility of these risks.8-10
Educate your patients about vaping
The public health implications are significant, particularly given the rapid rise in e-cigarette use among adolescents and young adults. Cognitive changes linked to e-cigarettes may affect not only academic performance and daily functioning but could also predispose users to neurodegenerative diseases later in life. Further research is needed to reveal the full extent of cognitive risks and to identify specific compounds in e-cigarette vapor responsible for these effects.
Even though e-cigarettes may offer a harm reduction alternative for current smokers, their potential to impair cognitive functions should not be overlooked. Mechanisms such as neuroinflammation, oxidative stress, and nicotine’s effects on neural signaling appear to underlie these risks, emphasizing the need for caution and regulatory policies.
We must strive to minimize e-cigarette exposure in vulnerable populations. Public health campaigns should address misconceptions about their safety so people are aware of the risks associated with e-cigarettes.
References
1. Prasedya ES, Ambana Y, Martyasari NWR, Aprizal Y, Nurrijawati, Sunarpi. Short-term e-cigarette toxicity effects on brain cognitive memory functions and inflammatory responses in mice. Toxicol Res. 2020;36(3):267-273. doi:10.1007/s43188-019-00031-3
2. Alzoubi KH, Batran RM, Al-Sawalha NA, et al. The effect of electronic cigarettes exposure on learning and memory functions: behavioral and molecular analysis. Inhal Toxicol. 2021;33(6-8):234-243. doi:10.1080/08958378.2021.1954732
3. Zelikoff JT, Parmalee NL, Corbett K, Gordon T, Klein CB, Aschner M. Microglia activation and gene expression alteration of neurotrophins in the hippocampus following early-life exposure to e-cigarette aerosols in a murine model. Toxicol Sci. 2018;162(1):276-286. doi:10.1093/toxsci/kfx257
4. Tobore TO. On the potential harmful effects of e-cigarettes (EC) on the developing brain: the relationship between vaping-induced oxidative stress and adolescent/young adults social maladjustment. J Adolesc. 2019;76:202-209. doi:10.1016/j.adolescence.2019.09.004
5. Yuan M, Cross SJ, Loughlin SE, Leslie FM. Nicotine and the adolescent brain. J Physiol. 2015;593(16):3397-3412. doi:10.1113/JP270492
6. Dai HD, Doucet GE, Wang Y, et al. Longitudinal assessments of neurocognitive performance and brain structure associated with initiation of tobacco use in children, 2016 to 2021. JAMA Netw Open. 2022;5(8):e2225991. doi:10.1001/jamanetworkopen.2022.25991
7. Lechner WV, Murphy CM, Colby SM, Janssen T, Rogers ML, Jackson KM. Cognitive risk factors of electronic and combustible cigarette use in adolescents. Addict Behav. 2018;82:182-188. doi:10.1016/j.addbeh.2018.03.006
8. Novak ML, Wang GY. The effect of e-cigarettes on cognitive function: a scoping review. Psychopharmacology (Berl). 2024;241(7):1287-1297. doi:10.1007/s00213-024-06607-8
9. López-Ojeda W, Hurley RA. Vaping and the brain: effects of electronic cigarettes and e-liquid substances. J Neuropsychiatry Clin Neurosci. 2024;36(1):A41-A45. doi:10.1176/appi.neuropsych.20230184
10. Novak ML, Gyawali P, Wang GY. Association between e-cigarettes, cognition and mood in adolescents. Substance Use & Misuse. 2024;59(12):1820–1827. doi:10.108/10826084.2024.2383597
