Summary: A large longitudinal study indicates that people whose biological age is older than their chronological age face a higher risk of developing dementia. Biological age—estimated from biomarkers such as lung function, blood pressure, cholesterol and blood cell measures—reflects how the body’s organs and systems are aging and may help identify individuals at increased risk of cognitive decline.
Researchers found that advanced biological age was associated with brain changes commonly linked to dementia, including reduced gray matter volume. While the study demonstrates a clear association, it does not prove causation; nevertheless, the findings suggest that slowing biological aging through healthier lifestyles could be one way to reduce dementia risk.
Key facts
- About 30% higher risk: Participants with the most advanced biological age had roughly a 30% greater likelihood of developing dementia than those with the lowest biological age, after adjusting for other risk factors.
- Brain structure differences: Advanced biological age correlated with changes in brain structure, including loss of gray matter volume associated with dementia.
- Biological age is modifiable: Biomarkers that determine biological age are influenced by lifestyle factors such as diet, physical activity and other health behaviors.
Study overview
This research drew on a large United Kingdom database including 280,918 participants who were, on average, 57 years old at baseline and free of dementia. Participants were followed for an average of 14 years, during which time 4,770 developed dementia. The investigators used two established methods to estimate each person’s biological age from a combination of physiological and blood biomarkers—measures that capture the functional status of multiple organ systems, such as metabolism, immunity, liver and kidney function, and cardiovascular health.
Compared with participants who remained free of dementia, those who later developed the condition had higher chronological ages at baseline and notably higher biological ages as estimated by the biomarker algorithms. When participants were divided into four groups based on biological age, those in the highest group had about a 30% increased risk of dementia compared with those in the lowest group, even after accounting for chronological age, education, smoking and other potential confounders.
Interpretation and implications
The lead author, Yacong Bo, PhD, of Zhengzhou University in China, emphasized the urgency of identifying modifiable risk factors for dementia as its global impact grows. The study’s findings support the idea that biological aging, as captured by routine clinical and laboratory measures, may help identify individuals at elevated risk and could serve as a target for preventive strategies.
Importantly, the researchers report that changes in brain structure—such as gray matter loss—account for some, but not all, of the link between advanced biological age and dementia. This suggests that accelerated aging across body systems may contribute to dementia through several pathways, some observable on brain imaging and others reflected in bodily health markers.
What this means for individuals
Although chronological age cannot be changed, biological age may be influenced by lifestyle choices. Diet, regular physical activity, smoking cessation, maintaining healthy blood pressure and cholesterol, and managing chronic conditions are established ways to support overall health and may help slow biological aging. While this study does not prove that modifying biological age will prevent dementia, it strengthens the rationale for comprehensive risk-reduction efforts that promote healthier aging across multiple systems.
Limitations
The authors note important limitations. Participants in the database tended to be more health conscious than the general population, which could affect the absolute risk estimates and limit generalizability. The observational design cannot establish a direct cause-and-effect relationship between biological age and dementia. Residual confounding and measurement limitations are possible despite statistical adjustments.
Funding
The study received support from the Henan Province and Zhengzhou city governments in China.
About this aging and dementia research news
Author: Renee Tessman
Source: AAN
Contact: Renee Tessman – AAN
Image: The image is credited to Neuroscience News
Original research: The findings are scheduled to appear in Neurology