Vaping impairs brain function in adults

The use of electronic cigarettes appears to worsen cognitive function among US adults, according to a recent study.

“[I]n this study, we provided the very first evidence about the potential cross-sectional association of e-cigarette use with subjective cognitive complaints, which should raise concerns about possible cognitive effects of e-cigarette use, and further emphasize the importance of tobacco regulatory policy on flavoured e-cigarettes to protect public health,” the researchers said.

Drawing from the 2016 and 2017 versions of the Behavioural Risk Factor Surveillance System (BRFSS) national survey, the current study included 886,603 adults with available information regarding their smoking and vaping status.

The principal outcome was any subjective cognitive complaint, defined in the survey as having “serious difficulty concentrating, remembering, or making decisions,” and dichotomized according to the participants’ yes or no answers.

Based on the survey responses alone, smoking and vaping behaviours significantly correlated with having subjective cognitive complaints (p<0.0001). [PLoS One 2020;15:e0241599]

For instance, the percentages of dual users and current smokers reporting such a complaint were 27.53 percent and 20.37 percent, respectively. In never users, only 8.02 percent had subjective cognitive problems. Exclusive vapers were similarly affected, with complaint rates of 18.68 percent and 16.16 percent among current vapers who were ex-smokers and never smokers, respectively.

These interactions were confirmed in subsequent multivariable weighted logistic regression analyses. Compared to never users, participants who were currently using both electronic and combustible cigarettes were more than twice as likely to have a subjective cognitive complaint (odds ratio [OR], 2.07, 95 percent confidence interval, 1.66–2.60).

Similar estimates were obtained for current exclusive smokers (OR, 1.49, 95 percent CI, 1.32–1.69) and current vapers who were ex-smokers (OR, 1.94, 95 percent CI, 1.40–2.71) or who had never smoked (OR, 1.96, 95 percent CI, 1.16–3.30).

Even ex-smokers were at a higher risk of reporting subjective cognitive complaints than never users (OR, 1.25, 95 percent CI, 1.11–1.41).

Stratifying the above analyses according to age groups revealed important differences. Particularly, despite having a strong effect in the overall cohort, an exclusive history of vaping showed no significant impact on subjective cognitive complaints across all tested age groups. In the oldest category (≥65 years), such an exposure even had a protective effect (OR, 0.04, 95 percent CI, 0.01–0.27).

“Current vapers who never smoked in some age groups (for example, 35–49, 50–64, and ≥65) had a relatively small sample size, which might result in the inconclusive results in these age groups,” the researchers explained. In the two younger age groups (18–24 and 25–34 years), a relatively shorter time of exposure to electronic cigarettes or a more robust neurology may explain the null findings.

On the whole, “[t]here are several possible different interpretations for the association of vaping with subjective cognitive complaints,” they added. “One is that vaping or smoking could increase the risk of subjective cognitive complaints mainly through nicotine exposure. Another possible explanation is that patients having subjective cognitive complaints might use smoking or vaping to reduce cognitive symptoms.”

However, the present study is underpowered to determine the direction of the association or to establish causality. Future studies are required to elucidate more clearly the pathways between vaping and subjective cognitive impairments, and to better understand the role age plays.