Brain Structure, Cognitive Ability Linked to Childhood Tobacco Use

After a 2-year follow-up period, children who started tobacco use before age 10 had significantly worse cognitive performance and smaller brain structures, a cohort study reported.

According to JAMA Network Open.

at baseline and 2-year follow-up, Crystallized cognition composite scores were also significantly lower in former users.

In addition, structural MRI showed significant reductions in whole-brain measurements of cortical regions in former users at baseline and cortical volumes in former users at baseline and 2 years decrease, Hongying Daisy reports, Dr. Dai and colleagues at the University of Nebraska Medical Center in Omaha.

The researchers also found other reduced regions and volumes of multiple frontal, parietal and temporal lobes in tobacco users.

These results may be clinically important because childhood through early adolescence are critical periods of brain development.

The authors note that more and more youth use e-cigarettes and other non-cigarette tobacco products, with e-cigarettes overtaking cigarettes as the most used tobacco product among youth in 2014. They cite that in 2020, 19.6 percent of high school students reported using e-cigarettes in the past 30 days.

“Children’s exposure to nicotine risks long-term cognitive outcomes beyond self-management,” Dr. Steven R. Laviolette of the University of Western Ontario, Canada, noted in an editorial.

He cited previous evidence for a link between children’s exposure to parental secondhand smoke and deficits in midlife episodic memory function and associative learning, as well as impairments in short-term and spatial working memory.

“[I] Nicotine dependence is well known to be associated with a wide range of neuropsychiatric disorders, including mood and anxiety disorders, schizophrenia and other substance use disorders such as alcohol and marijuana use, although these combined Little is known about the mechanistic associations between diseases,” Laviolette said.

“Together, from preclinical and cclinical studies highlighting the neurotoxic effects of nicotine exposure during sensitive periods of brain development and highlighting the pathological interference of nicotine with many of the cognitive outcomes for health and long-term mental health,” he concluded.

This observational cohort study was conducted using 9 data from 21 sites in the United States. Data from the Adolescent Brain and Cognitive Development (ABCD) study of children up to 10 years of age.

Data were collected on 11,729 participants (mean age 9.9 years, 52.1% boys, 52.1% non-Hispanic whites) from October 2016 to October 2018 and conducted 2 year follow-up. Findings were adjusted for age, sex at birth, race and ethnicity, other substance use, puberty, parental supervision and school environment.

Tobacco use was assessed through questions on e-cigarettes, cigarettes, cigars, smokeless tobacco, hookahs, pipes, and nicotine substitute use. Participants who answered affirmatively to any of these questions were classified as former users.

Dai’s group acknowledges that ABCD study participants may not be fully nationally representative. Tobacco use is self-reported and can be influenced by social desirability bias, especially among adolescents. A causal relationship cannot be established based on the data in this study either.