Nicotine use in youth linked to altered brain blood flow, study finds

In a recent study, researchers discovered that frequent use of nicotine products by young adults and adolescents is associated with changes in brain blood flow, particularly in areas critical to addiction and cognitive function. The findings have been published in Brain Imaging and Behavior.

For years, public health experts have been concerned about the high use of nicotine and tobacco products among young people. Despite numerous efforts to curb this trend, the popularity of e-cigarettes and traditional smoking persists. Prior research has highlighted the potential risks associated with nicotine use, particularly its impact on the developing brain. Building on this knowledge, researchers sought to investigate how nicotine use might affect brain health, specifically focusing on blood flow within the brain, a key factor for healthy brain function.

“We still don’t fully understand how nicotine use affects the brain, particularly during late adolescence/young adulthood (ages 16-22) when the brain is undergoing rapid neural development,” said study authors Kelly Courtney and Joanna Jacobus, who are both associate professors of psychiatry at UC San Diego.

“This is also the time period when many individuals begin using nicotine products for the first time. Cerebral blood flow is one measure of brain health that is particularly relevant as it supplies oxygen and energy substrates throughout the brain and supports the changes that occur during normal neural development. This study investigated whether there was a difference between adolescent/young adult nicotine users and non-users to see if there is any indication of nicotine-related effects on cerebral blood flow.”

The study involved 194 participants between the ages of 16 and 22, recruited from various educational institutions and via social media in San Diego County. The participants were divided into two groups based on their use of nicotine products: those who used such products at least weekly and those who used them less frequently.

The researchers conducted thorough assessments, including interviews, self-report surveys on substance use and mental health, and urine tests to measure nicotine metabolites. Importantly, participants underwent magnetic resonance imaging (MRI) scans to measure blood flow in the brain.

In the brains of frequent nicotine users, researchers noted a decrease in blood flow in specific areas: the left and right precuneus, left posterior cingulate cortex, and right anterior cingulate cortex. These areas are known to be crucial in the development of nicotine dependence and in managing cognitive functions like attention and memory.

Interestingly, the study found that as these young nicotine users got older, the decrease in blood flow in these areas became more pronounced, diverging from the pattern seen in non-users, who showed an increase in blood flow with age in these regions.

Moreover, the study observed that the decrease in brain blood flow correlated with higher levels of nicotine metabolites in urine and greater severity of nicotine dependence. However, there was no correlation between recent nicotine use and changes in blood flow, suggesting that these changes are a result of chronic, rather than acute, nicotine use.

“Results from our study suggest that nicotine use during adolescence may affect the normal changes to cerebral blood flow that occur during neural development,” Courtney and Jacobus told PsyPost. “The results also suggest that specific brain regions, known as the precuneus, posterior cingulate cortex, and anterior cingulate cortex, are potential key regions involved in the development of nicotine dependence.”

While the study offers valuable insights, it is important to note its limitations. Its cross-sectional nature means it can’t definitively prove that nicotine use causes these changes in brain blood flow—only that there’s a link. Also, the study didn’t find any differences in effects based on the sex of the participants, which is inconsistent with some previous research. The researchers acknowledge that more complex factors, such as the interaction between sex, age, and nicotine use, could not be fully explored due to the study’s design.

Looking forward, longitudinal studies could track changes over time to better understand the causal relationships and potentially uncover sex-specific effects. This research is a step towards comprehending how nicotine use during critical developmental periods can influence the brain, ultimately aiding in the development of more effective public health strategies to address nicotine and tobacco use in youth.

The study, “The effects of nicotine use during adolescence and young adulthood on gray matter cerebral blood flow estimates“, was authored by Kelly E. Courtney, Rachel Baca, Courtney Thompson, Gianna Andrade, Neal Doran, Aaron Jacobson, Thomas T. Liu, and Joanna Jacobus.