In the largest study of the associations between smoking and cardiovascular disease on cognitive function, researchers found that both impair the ability to learn and memorise, according to research published in the journal Scientific Reports. The effects of smoking are more pronounced among females, while males are more impaired by cardiovascular disease.
Previous attempts to quantify cognitive function among smokers and assess sex differences produced mixed results. Researchers from the Translational Genomics Research Institute (TGen), as well as universities in the United States and Norway, attribute this to the limited size of previous data sets.
By analysing data representing more than 70,000 individuals worldwide – generated through TGen’s online cognitive test called MindCrowd – the current study produced results that indicate definitive trends, writes Steve Yozwial in a TGen article published on 13 May 2021.
“These results suggest that smoking and cardiovascular disease impact on verbal learning and memory throughout adulthood, starting as early as age 18,” said Matt Huentelman, TGen Professor of Neurogenomics, a MindCrowd founder, and the study’s senior author.
“Smoking is associated with decreased learning and memory function in women, while cardiovascular is associated with decreased learning and memory function in men.”
Besides Alzheimer’s disease, the most significant cause of cognitive decline is known as “vascular contributions to cognitive impairment and dementia” or VCID, which arises from stroke and other vascular brain injuries that cause significant changes to memory, thinking and behaviour: smoking and cardiovascular disease exacerbate VCID.
“The reasons for these sex-modification effects are not entirely understood,” said Dr Candace Lewis, a Postdoctoral Fellow in Huentelman’s Lab and the study’s lead author. “Our findings highlight the importance of considering biological sex in studying vascular contributions to cognitive impairment and dementia.”
This study’s findings are important, Lewis said, since cigarette smoking is the nation’s leading cause of preventable disease and death, accounting for nearly one in five deaths, and cardiovascular disease is the leading cause of disease and death worldwide, and is an important predictor of cognitive decline and VCID.
Vascular diseases also are associated with increased risk of Alzheimer’s, which is the nation’s sixth leading cause of death.
Because the study included a wide range of adults, aged 18 to 85, it allowed researchers to assess the relationship between smoking, cardiovascular disease, and verbal memory in the broadest single study age range used to date.
The researchers noted that few studies have previously assessed the effects of cardiovascular disease in younger adults, and that understanding the relationship between cardiovascular disease and cognitive function in young adults may be necessary for understanding possible treatment and intervention opportunities.
“This study points out some unpredicted but important differences between the sexes relating to cognitive decline,” said Dr Brian Tiep, City of Hope director of pulmonary rehabilitation and smoking cessation.
“The impact on mental acuity seems progressive over time – some more rapid than others. Living habits related to diet, exercise and smoking certainly are consequential and may differ between men and women. People undergoing cancer care may be cognitively effected by the cancer and its treatment.
“This study supports the importance of maintaining cardiovascular health and quitting smoking not only in support of their cancer care but to improve brain function,” Tiep added.
Also contributing to this study were: the Arizona Alzheimer’s Consortium, the Norwegian University of Science and Technology, the Evelyn F McKnight Brain Institute at the University of Miami, the Miami Clinical and Translational Science Institute, and the University of Arizona.
Study details
Smoking is associated with impaired verbal learning and memory performance in women more than men
CR Lewis, JS Talboom, MD De Both, AM Schmidt, MA Naymik, AK Haberg, T Rundek, BE Levin, S Hoscheidt, Y Bolla, RD Brinton, M Hay, CA Barnes, E Glisky, L Ryan and MJ Huentelman.
Published by Scientific Reports, Volume 11, article number 10248 (2021), on 13 May 2021.
Abstract
Vascular contributions to cognitive impairment and dementia (VCID) include structural and functional blood vessel injuries linked to poor neurocognitive outcomes. Smoking might indirectly increase the likelihood of cognitive impairment by exacerbating vascular disease risks.
Sex disparities in VCID have been reported, however, few studies have assessed the sex-specific relationships between smoking and memory performance and with contradictory results.
We investigated the associations between sex, smoking, and cardiovascular disease with verbal learning and memory function. Using MindCrowd, an observational web-based cohort of ~ 70,000 people aged 18-85, we investigated whether sex modifies the relationship between smoking and cardiovascular disease with verbal memory performance.
We found significant interactions in that smoking is associated with verbal learning performance more in women and cardiovascular disease more in men across a wide age range.
These results suggest that smoking and cardiovascular disease may impact verbal learning and memory throughout adulthood differently for men and women.
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