A study published in Neurology®, the journal of the American Academy of Neurology, on June 11, 2025, has found that short leukocyte telomere length is linked to a higher risk of stroke, dementia, and late-life depression. However, the study also highlighted that individuals with healthy lifestyle habits, including good diet, low cholesterol, and controlled blood pressure, did not show this increased risk.
While the research establishes an association, it does not prove that shorter telomeres directly cause these brain diseases. The findings underscore the importance of maintaining a healthy lifestyle to reduce the risk of age-related brain conditions, even in those showing signs of biological aging, according to study author Dr. Christopher D. Anderson, MD, MMSc, of Harvard Medical School.
Telomeres, which are protective caps at the ends of chromosomes, shorten each time a cell divides, making them a key marker of biological aging. This study focused on the length of telomeres in white blood cells (leukocytes) to assess the relationship between telomere length and brain health.
Researchers analyzed data from 356,173 people in the United Kingdom, with an average age of 56. Participants were categorized based on their telomere length—short, medium, or long—and their health factors, such as diet and smoking habits. A modified Brain Care Score, which evaluates risk factors for stroke, dementia, and depression, was also used to gauge overall brain health.
After following participants for an average of seven years, 25,964 developed at least one of the three brain diseases. The study found that individuals with the shortest telomeres had 5.82 cases of brain diseases per 1,000 person-years, compared to 3.92 cases per 1,000 person-years in those with the longest telomeres. Adjusting for factors like age, blood pressure, and smoking, researchers found that those with shorter telomeres were 11% more likely to develop brain diseases than those with longer telomeres.
However, when factoring in the Brain Care Scores, individuals with short telomeres who had higher scores did not show a higher risk of developing these brain conditions. This suggests that a healthy lifestyle may help delay cellular aging and reduce the likelihood of age-related brain diseases, especially for those at higher risk.
One limitation of the study is its focus on participants of European ancestry, which may limit the applicability of the findings to other populations. The research was funded by the American Heart Association-Bugher Foundation Centers of Excellence, the National Institutes of Health, and the Massachusetts General Hospital McCance Center for Brain Health.
Related Topics
