Shorter telomeres linked to higher risk of stroke and dementia, but healthy habits may cancel it out
People with shorter telomeres – protective caps on the ends of chromosomes found in white blood cells – may be at greater risk of stroke, dementia and depression in later life, new research suggests.
But individuals with healthy lifestyle habits appear to face no added risk, despite having this biological marker of ageing.
The study tracked the health records of 356,173 people in the UK, with an average age of 56. It examined the length of telomeres in leukocytes (white blood cells) and followed their health outcomes over seven years.
Telomeres protect chromosomes from damage and shorten as cells divide over time. This process is thought to reflect biological ageing and the accumulation of stress over a person’s lifetime.
Researchers divided participants into three groups based on telomere length and assessed their lifestyle choices using a modified Brain Care Score – a 19-point system evaluating diet, exercise, sleep, alcohol use and the management of blood pressure and cholesterol. Scores of 15 or higher were considered good brain care, while 10 or below indicated poor brain care.
Over the follow-up period, 25,964 participants were diagnosed with at least one age-related brain condition. Those with the shortest telomeres saw 5.82 cases per 1,000 person-years, compared to 3.92 cases among those with the longest.
After accounting for factors such as age, smoking and high blood pressure, individuals with short telomeres were found to be 11 per cent more likely to develop stroke, dementia or depression later in life than those with longer telomeres.
However, this increased risk was not seen among people who scored 15 or higher on the Brain Care Score, regardless of their telomere length.
The study does not show that shorter telomeres cause these brain conditions – only that there is an association.
“Our findings support the potential benefits of working to improve your risk factors such as maintaining a healthy weight, limiting alcohol and getting enough sleep and exercise in reducing the risk of age-related brain disease even in people who are already showing signs of damaging biological ageing,” said study author Christopher D. Anderson, MD, MMSc.
The results suggest that certain lifestyle behaviours – including regular exercise, good sleep habits and healthy weight management – may help offset cellular ageing and reduce the risk of brain-related diseases.
“These results suggest that healthy lifestyle behaviours could delay the ageing of our cells and reduce the frequency of these diseases, especially in people who are at greater risk,” said Anderson.
Participants were followed for an average of seven years, during which time researchers monitored three specific outcomes: stroke, dementia and late-life depression.
The study only included people of European ancestry, which researchers acknowledged as a limitation.
It was supported by the American Heart Association-Bugher Foundation Centres of Excellence in Hemorrhagic Stroke Research, the National Institutes of Health and the Massachusetts General Hospital McCance Centre for Brain Health.
