A pair of large observational studies are suggesting a possible link between e-cigarette use and cognitive complaints such as memory impairments and brain fog. The cross-sectional research does not present evidence for a causal link between vaping and cognitive problems but instead calls for further longitudinal investigation into the potential relationship.
Rates of teenage tobacco use have dramatically declined over the past few decades. E-cigarette use, on the other hand, has rapidly grown in recent years. In 2018 the US Surgeon General even declared e-cigarette use among America's youth a national epidemic. But debates are ongoing over whether e-cigarettes are a gateway to traditional tobacco smoking and scientists are still investigating the long-term health effects of vaping.
Looking at data from two big population surveys, researchers from the University of Rochester Medical Center have detected a novel association between specific self-reported cognitive complaints and e-cigarette use, in both adults and adolescents. The first study, published in the journal Tobacco Induced Diseases, looked at data from more than 18,000 US high school students.
The research revealed those adolescents who smoked tobacco or used e-cigarettes self-reported higher levels of difficulty concentrating, remembering, or making decisions. This association was stronger the earlier a subject started vaping, with those using e-cigarettes between the ages of eight and 13 most likely to report cognitive complaints.
The second study, published in the journal Plos One, looked at two years of data from an annual phone survey called the Behavioral Risk Factor Surveillance System. More than 800,000 adults were surveyed in the study, and again a distinct association was detected between e-cigarette use and cognitive complaints.
Traditional tobacco smokers and e-cigarette users both reported a similar higher frequency of cognitive complaints compared to non-smokers but dual users (those who smoked tobacco and vaped) were even more likely to report problems. These results were based on a single yes/no survey question asking if a subject has, “serious difficulty concentrating, remembering, or making decisions?”
Of course, correlation is not causation, and the researchers stress there is no clear indication that e-cigarette use is directly causing these attentional deficits. In fact, the Plos One study clearly points out it is possible this observed association is due to those with pre-existing cognitive complaints hypothetically being more likely to take up smoking or vaping in the first place.
“[A] possible explanation is that patients having subjective cognitive complaints might use smoking or vaping to reduce cognitive symptoms,” the researchers hypothesize. “Several studies showed that mental health problems (such as anxiety, depressive, and substance use symptoms) could lead to the initiation of e-cigarette use. One possible reason is that smokers or vapers believe smoking or vaping could help with their mental health problems.”
Dongmei Li, lead researcher on the two studies, says the only way to fully understand the causal relationship is to conduct detailed longitudinal research. E-cigarette use is relatively new so the long-term health effects are still unclear.
In the short term, Li suggests more public health interventions may be necessary to prevent e-cigarette use in very young populations. While it is increasingly clear e-cigarettes are not as generally harmful as traditional tobacco smoking, they are certainly not harmless, and it is that message Li is most keen to convey.
“Our studies add to growing evidence that vaping should not be considered a safe alternative to tobacco smoking,” says Li. “With the recent rise in teen vaping, this is very concerning and suggests that we need to intervene even earlier. Prevention programs that start in middle or high school might actually be too late.”
The adult study was published in the journal PLOS ONE, while the high school study was published in the journal Tobacco Induced Diseases.
