Researchers have discovered that individuals whose bodies age faster than their chronological age face a significantly higher risk of developing dementia, according to a comprehensive study published April 30 in the journal Neurology.
The study found that people with advanced biological aging are approximately 30% more likely to develop dementia compared to those whose biological age more closely matches their chronological age, even after accounting for established risk factors such as education level and smoking history.
"These results support the hypothesis that advanced biological age may contribute to the development of dementia by causing a widespread change in brain structure," said lead researcher Yacong Bo from Zhengzhou University in China.
Biological vs. Chronological Aging
Biological age reflects the cumulative damage to bodily systems over time, while chronological age simply measures years since birth. The distinction is crucial because biological aging can be influenced by lifestyle factors.
"While none of us can change our chronological age, we can influence our biological age through lifestyle factors such as diet and exercise," Bo explained.
The research team analyzed medical data from nearly 281,000 participants in the UK Biobank, a long-term health study of United Kingdom residents with an average chronological age of 57 at the study's commencement. During the average 14-year follow-up period, approximately 4,800 participants developed dementia.
Measuring Biological Age
To estimate biological age, researchers employed two established methodologies that considered multiple physiological factors including:
- Lung function
- Blood pressure
- Cholesterol levels
- Blood chemistry markers
These measurements provide insight into how different bodily systems—including metabolism, immune function, and major organs—work together during the aging process.
Brain Structure Changes
MRI scans revealed that participants with advanced biological aging exhibited significant shrinkage of gray matter, the brain tissue responsible for information processing. However, these structural changes only partially explained the connection between accelerated aging and dementia risk.
"These brain structure changes explain some, but not all, of the association between advanced biological age and dementia," Bo noted, suggesting multiple pathways may be involved in this relationship.
Dementia Risk Factors Emerge Early in Life
In a complementary study published in the May issue of The Lancet: Regional Health Americas, researchers found that risk factors for dementia may begin affecting cognitive function decades earlier than previously thought—as early as a person's 20s and 30s.
This groundbreaking research examined young adults between ages 24 and 44, finding that those with higher Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) scores performed worse on cognitive tests.
"Previously, research on Alzheimer's disease risk factors has focused on individuals aged 50 and older," said lead researcher Allison Aiello, a professor of epidemiology at the Columbia University Aging Center. "Our findings show that well-established risk factors and blood biomarkers for dementia appear to start affecting cognitive function even before middle age."
Biomarkers Present Decades Before Symptoms
The study also revealed that certain Alzheimer's biomarkers—including amyloid beta and tau proteins that form characteristic brain plaques and tangles—were associated with cognitive function prior to middle age.
"Our overall findings suggest that blood-based biomarkers associated with Alzheimer's disease are linked to differences in cognitive function decades before clinical symptoms and impairments even appear, highlighting the importance of early prevention strategies across the life course," Aiello explained.
Implications for Prevention and Treatment
These studies collectively emphasize the importance of early intervention in dementia prevention. The identification of biological aging as a risk factor opens new avenues for potential treatments and preventive strategies.
Health experts suggest that addressing modifiable risk factors early in life—including cardiovascular health, education, physical activity, and diet—may help slow biological aging and potentially reduce dementia risk.
"Identifying the early pathways to Alzheimer's disease and cognitive impairment before older age is critical to slowing the expected rise of Alzheimer's disease in the coming decades," Aiello concluded.
The findings represent a significant advancement in understanding dementia's developmental trajectory and may ultimately lead to earlier interventions that could delay or prevent cognitive decline in vulnerable populations.
