Recent research has indicated that individuals with shorter telomeres—protective caps located at the ends of chromosomes in their white blood cells—may face higher risks of strokes, dementia, and late-onset depression. However, engaging in healthy lifestyle practices, such as maintaining a balanced diet and regular exercise, may mitigate these risks. These findings were recently shared at the International Stroke Conference held by the American Stroke Association in Los Angeles, though they are considered preliminary pending publication in a peer-reviewed journal.
Dr. Tamara N. Kimball, a postdoctoral research fellow at the Henry and Allison McCance Center for Brain Health at Massachusetts General Hospital in Boston and one of the study’s co-authors, emphasized that previous research has not thoroughly investigated how the length of telomeres in white blood cells relates to age-associated brain conditions like stroke and dementia. Kimball pointed out that all three conditions are connected to cerebral small vessel disease, which is often a result of aging and the buildup of vascular risk factors.
As a person ages, leukocyte telomeres shorten, reducing their capacity to safeguard genetic material, thus accelerating cell aging and enhancing vulnerability to diseases typically associated with older age. While factors such as genetics, ancestry, and gender influence telomere length—elements that are beyond an individual’s control—lifestyle choices and external environmental stressors, like pollution, can be modified for potential health benefits. Kimball remarked that assessing leukocyte telomere length could help identify individuals who may benefit from more rigorous health monitoring or preventive strategies, potentially leading to personalized lifestyle changes and treatments for better overall health.
However, given that the connection between leukocyte telomere length and stroke risk is still in its exploratory phase, Kimball advocates against adopting this measurement as routine practice for health assessments. The study involved an analysis of data from 356,173 participants enlisted in the UK Biobank, a significant population-based project that recruited individuals from 22 health centers across the United Kingdom between 2006 and 2010, with a mean age of 57 at enrollment. Blood samples were utilized to evaluate leukocyte telomere length, categorizing them into shortest, intermediate, and longest groups.
Additionally, a Brain Care Score was employed to measure modifiable risk factors, including blood pressure, diet, exercise habits, stress, and the quality of social ties. At the outset, no participants had received diagnoses for stroke, dementia, or depression. Over a median follow-up period of 12 years, those with shorter leukocyte telomeres exhibited an 11% increased risk of developing at least one of the three age-related conditions compared to those with longer telomeres. Specifically, there was an 8% higher risk for strokes, 19% for dementia, and a 14% increased risk for depression diagnosed in individuals aged 60 or older.
Remarkably, the research inferred that adopting healthier lifestyles might help alleviate the risks linked to shorter telomeres. For instance, individuals with shorter leukocyte telomeres and low Brain Care scores, indicative of poor health behaviors, faced an 11% heightened risk of stroke, dementia, and depression. Conversely, those with higher scores—reflective of healthier lifestyle choices—did not show an increased risk for any of the three conditions despite having shorter telomeres.
Kimball highlighted that the research did not establish a direct causal relationship between telomere shortening and the conditions, but rather suggested that telomere length might serve as a marker for underlying biological processes and cellular stress that precede age-related ailments. She encouraged that it is never too late to adopt healthier practices to care for one’s brain, reinforcing the idea that healthier lifestyle choices may counteract the adverse effects associated with shorter telomeres.
The researchers also identified certain limitations in the study, including the fact that telomere lengths and Brain Care scores were solely assessed at the beginning, meaning any subsequent changes weren’t accounted for. Furthermore, the study’s focus on individuals with European ancestry may limit the broader applicability of the results.
Dr. Costantino Iadecola remarked on the study’s implications, noting the well-established connection between aging and conditions such as stroke and dementia. He pointed out that the findings regarding telomere shortening in white blood cells as a potential indicator of aging hold significant potential for evaluating risks and predicting health outcomes. Iadecola, the director of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine, explained that emerging research suggests various parts of the body age at different rates, each operating on distinct “aging clocks,” linking longer telomeres in white blood cells to a reduced risk of major age-related brain diseases, thereby establishing a connection between immune system aging and brain health.
