New Study Shows Biological Age Could Predict Risk of Dementia and Stroke
As we journey through life, the risk of developing chronic diseases, including cancer, heart disease, and neurological disorders, increases significantly. However, while we all grow older chronologically at the same pace, biologically, our clocks can tick faster or slower. Relying solely on chronological age – the number of years since birth – is inadequate to measure the body’s internal biological age.
This discrepancy has prompted scientists to find ways to determine a person’s biological age. One way is to look at “epigenetic clocks” which consider chemical changes that occur in our DNA as we age. Another approach uses information from medical tests, such as blood pressure, cholesterol levels, and other physiological measurements.
By using these “biomarkers”, researchers have discovered that when a person’s biological age surpasses their chronological age, it often signifies accelerated cell aging and a higher susceptibility to age-related diseases.
New research suggests that biological age, more than the years lived, may predict the risk of dementia and stroke in the future. Previous studies have shed light on this association but they were often limited in scale. This has left gaps in our understanding of how biological ageing relates to various neurological disorders, including Parkinson’s disease and motor neuron disease.
To bridge this gap, a recent study published in the Journal of Neurology, Neurosurgery and Psychiatry examined over 325,000 middle-aged and older British adults. Researchers investigated whether advanced biological age increases the future risks of developing neurological diseases, including dementia, stroke, Parkinson’s disease, and motor neuron disease.
To assess biological age, 18 biomarkers collected during medical checkups were analyzed. These included blood pressure, blood glucose, cholesterol levels, inflammation markers, waist circumference, and lung capacity. Participants were followed for nine years to see who developed neurological diseases. Those with older biological ages at the study’s start had significantly higher risks of dementia and stroke over the next decade – even after considering differences in genetics, sex, income, and lifestyle.
The study found a strong association between advanced biological age and dementia and stroke, with weaker links to motor neuron disease and even an opposite direction for Parkinson’s disease. This suggests that biological ageing processes probably contribute substantially to dementia and stroke later in life.
Assessing biological age from routine blood samples could someday become standard practice. Those with accelerated ageing could be identified decades before dementia symptoms arise, providing opportunities for preventive lifestyle changes and close monitoring. Lifestyle interventions including exercise, sleep, diet, and nutritional supplements could potentially slow down or even reverse biological age.
The results of the study suggest that monitoring internal ageing processes could empower people to delay cognitive decline, providing hope for a healthier and more fulfilling life in later years.
Jonathan Ka Long Mak, PhD Candidate, Karolinska Institutet and Sara Hägg, Associate Professor, Molecular Epidemiology, Karolinska Institutet