Researchers Identify Link Between Alzheimer's and Telomere Length in Brain

A new study led by Anya Topiwala of Oxford Population Health, part of the University of Oxford, UK, has found that brain alterations induced by Alzheimer’s disease are associated with the shortened telomeres. The study, published in the journal PLoS ONE, is the largest study of the relationships between telomere length and MRI markers in the brain. The analysis revealed that patients with longer telomeres also tended to have better brain health, with a larger volume of grey matter and a larger hippocampus, both of which shrink in Alzheimer’s patients. Longer telomeres were also associated with a thicker cerebral cortex, which thins as Alzheimer’s disease progresses. 

These findings suggest that shorter telomeres can be linked to multiple neuronal changes associated with dementia, and that accelerated aging in the brain, as indicated by telomere length, could represent a biological pathway leading to neurodegenerative disease.

Telomeres on chromosomes protect from DNA degredation, but every time a cell divides, the telomeres lose some of their length. Short telomeres are a sign of stress and cellular aging, and are associated with a higher risk of neurological and psychiatric disorders. Currently, little is known about the links between telomere length and changes that occur in the brains of people with neurological conditions. Understanding those relationships could offer insights into the biological mechanisms that cause neurodegenerative disorders.

The study compared telomere length in white blood cells to results from brain MRIs and health records from more than 31,000 participants 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. Longer telomeres were protective against certain related clinical manifestations, namely all-cause dementia, but not stroke or Parkinson’s disease.

The findings of the study suggest that LTL is associated with multiple MRI endophenotypes of neurodegenerative disease, suggesting a pathway by which longer LTL may confer protection against dementia. Peripheral blood markers of cell aging are the most practical markers to obtain for epidemiological studies. The study offers insights into the biological mechanisms of neurodegenerative disorders, which could be used to develop new treatments and therapies for those suffering from dementia and other neurological conditions.