Researchers at the University of Oxford’s Big Data Institute, along with colleagues at the Wellcome Centre for Integrative Neuroimaging at the University of Oxford, King’s College London, and the University of Leicester, have found associations between telomere length and endophenotypes, or markers, of neurodegenerative disease that suggest longer telomeres may have protective effects against dementia. The results are published in PLOS ONE.
Telomeres are the protective caps on the end of chromosomes that protect their DNA from degrading and enable our bodies to function properly. As cells age and continue to divide, telomeres become progressively shorter. Shorter telomeres are a marker of biological ageing and may increase likelihood of age-related diseases such as dementia but it is unclear why this occurs.
Previous studies have shown that changes in the brains of people with neurodegenerative diseases often occur before they experience symptoms. To understand how changes in the brain that are associated with neurodegenerative disease can be linked to biological ageing, researchers compared telomere length in white blood cells with results from brain MRI scans and electronic health records from 31,661 UK Biobank participants.
- People with longer telomeres tended to have larger volumes of grey matter in their brains and a larger hippocampus, the part of our brain that plays a vital role in learning and memory and gets progressively smaller in people with dementia;
- Longer telomeres were associated with a thicker cerebral cortex, which is the outer, folded layer of grey matter that becomes thinner with cognitive decline;
- There was no association between telomere length and people who experienced strokes or developed Parkinson’s disease.
Dr Anya Topiwala, Wellcome Clinical Career Development Fellow at the Big Data Institute and consultant psychiatrist at Oxford Health NHS Foundation Trust, said ‘Understanding the biological mechanisms that cause neurodegenerative disease is an important first step to developing new treatments to either prevent or slow down disease progression. These findings suggest that telomere length may have protective effects against dementia and provide a pathway for future research.’