Scientists from Mass General Brigham explored the associations between telomere length—which decreases as a person ages or is exposed to unhealthy environments—and the risk for age-related brain diseases. The research team found evidence suggesting that healthier lifestyle choices could mitigate telomere length-associated risks. Their results are published in Neurology , the medical journal of the American Academy of Neurology.
"Reducing risk factors like weight and alcohol consumption as well as getting more sleep and exercise can all help reverse the risk of age-related brain diseases, even for people who are already showing signs of biological aging," said lead author Tamara Kimball, MD, from the Center for Neurotechnology and Neurorecovery at Massachusetts General Hospital, a founding member of the Mass General Brigham healthcare system. "In short, it is never too late to start taking better care of your brain."
The risk of stroke, dementia, and late-life depression (LLD) increases for people as they get older. Likewise, telomeres, which are protective caps on chromosomes, naturally shorten with age, or exposure to adverse environmental conditions, like stress and pollution, increasing the risk for DNA damage. This study sought to determine the association between these age-related brain diseases and leukocyte telomere length (LTL), and whether LTL was a direct causal factor or merely a predictive marker for brain diseases.
To investigate this relationship, the research team analyzed data from 356,173 participants in the UK Biobank. They also used the McCance Brain Care Score (BCS), which accounts for factors like blood pressure, blood sugar levels, cholesterol, and lifestyle behaviors, and social-emotional aspects that influence risk factor profiles.
Their findings showed that individuals with shorter LTLs and lower BCSs, reflecting less optimal lifestyle choices, were at greater risk for these brain diseases. Notably, those with shorter LTLs but healthier lifestyle scores (high BCS) did not show a significantly increased risk, suggesting that a high BCS may mitigate the effects of short telomeres.
One notable limitation of the study was that LTL was only measured at the initial visit, and so telomere shortening could not be tracked over time. Additionally, the study only included individuals of European descent, which limits its generalizability. Nevertheless, reducing risk factors appears to mitigate the negative effects of shorter telomeres on cerebral health, which sets the stage for future studies to explore whether lifestyle interventions can in fact slow aging's effects on the brain.
Authorship: In addition to Kimball, Mass General Brigham authors include Savvina Prapiadou, Reinier WP Tack, Benjamin YQ Tan, Jasper R. Senff, Chrisna Kourkoulis, Sanjula D. Singh, Jonathan Rosand, Christopher D. Anderson.
Disclosures: None.
Funding: This study was funded in part by the National Institutes of Health (T32 Fellowship NS100663-06A1, R01NS103924, and U01NS069673), the American Heart Association (18SFRN34250007), the American Heart Association (21SFRN812095), and the MGH McCance Center for Brain Health.
Paper Cited: Kimball, T et al. "Association of Leukocyte Telomere Length with Stroke, Dementia, and Late-Life Depression: The Role of Modifiable Risk Factors" Neurology DOI: 10.1212/WNL.0000000000213794
