A new study led by Anya Topiwala of Oxford Population Health, part of the University of Oxford, UK, and published in the journal PLOS One found that shortening of telomeres, the protective caps on the ends of chromosomes, shortens with age and is associated with changes in the brain caused by Alzheimer’s disease.
More than 31,000 people who participated in the UK Biobank, a large-scale biomedical database and research resource containing anonymized genetic, lifestyle, and health information from half a million UK participants, had their white blood cell telomere length compared to results from brain MRIs and electronic health records for the new study.
This study found that patients with longer telomeres also had better overall brain health. Both the total volume of gray matter in the brain and the size of the hippocampus were greater in these people than in Alzheimer’s patients.
The outer, folded layer of gray matter (the cerebral cortex) thins with the onset and development of Alzheimer’s disease, but longer telomeres were also linked to a thicker cortex. Because of this, the researchers hypothesize that longer telomeres may protect patients from developing dementia, though there was no correlation with stroke or Parkinson’s disease.
The results link shorter telomeres to several dementia-related brain changes. This is the most comprehensive analysis to date of the associations between telomere length and brain MRI markers. The correlations raise the possibility that shorter telomeres, an indicator of faster brain aging, represent a biological pathway leading to neurodegenerative disease.