Age has traditionally been measured by calendar years, but emerging research suggests that the body’s internal clock—biological age—may offer more meaningful insights into health risks, particularly for neurological conditions like dementia.
A groundbreaking study published in Neurology on April 30, 2025, has revealed that individuals whose biological age exceeds their chronological age face a significantly higher risk of developing dementia, highlighting the importance of understanding how our bodies age beyond simple calendar years.
This comprehensive research, led by scientists at Zhengzhou University in China, provides compelling evidence that addressing biological aging factors may offer new avenues for dementia prevention.
With more than 6 million Americans currently living with dementia and global numbers projected to reach 139 million by 2050, these findings could have profound implications for public health strategies and individual wellness approaches.
Understanding the Age Divide: Biological vs. Chronological
What Is Biological Age?
Biological age reflects how well the body’s systems are functioning relative to chronological age. Unlike chronological age, which simply counts years since birth, biological age provides insight into the actual physiological state of the body based on various biomarkers. These biomarkers measure the health and performance of multiple bodily systems, including:
- Cardiovascular function
- Metabolic health
- Immune system efficiency
- Respiratory capacity
- Cellular integrity
Biological age is determined through measurements of specific biomarkers such as:
- Lung function
- Blood pressure
- Cholesterol levels
- Blood cell metrics (average cell volume, white blood cell count)
- Metabolic indicators
- Inflammatory markers
Why the Distinction Matters
The distinction between biological and chronological age has profound implications for health assessment and disease risk prediction.
Two individuals of the same chronological age may have vastly different biological ages based on genetics, lifestyle choices, and environmental exposures. This divergence can translate to significantly different health trajectories and disease risks.
Dr. Yacong Bo, the study’s lead author, emphasizes this point: “While none of us can change our chronological age, we can influence our biological age through lifestyle factors such as diet and exercise.” This highlights the modifiable nature of biological age, offering potential avenues for intervention to reduce disease risk.
The Landmark Study: Design and Findings
Research Methodology
The research team analyzed health data from the UK Biobank, a massive biomedical database containing in-depth genetic and health information. The study included 280,918 participants with an average age of 57 at baseline who did not have dementia when the study began. Researchers followed these individuals for an average of 14 years, during which 4,770 participants developed dementia.
To calculate biological age, the researchers employed two well-established methods:
- Klemera–Doubal Method Biological Age (KDM-BA): Uses blood test results and other biomarkers
- PhenoAge: Draws on clinical data tied to aging and mortality
These methods evaluate how different bodily systems—including metabolism, immunity, liver, kidneys, and cardiovascular function—operate collectively during the aging process.
Key Findings
The results revealed several significant patterns:
- Participants who later developed dementia had an average chronological age of 65 at the start of the study (compared to 57 for those who remained dementia-free)
- Their biological age averaged 55 by one measurement method (compared to 45 for those without dementia)
- When divided into four groups based on biological age, those with the most advanced biological age were approximately 30% more likely to develop dementia than those in the lowest group
Importantly, these results held true even after adjusting for other factors that could affect dementia risk, such as age, education level, and smoking status.
“With the rising impact of dementia around the world, identifying risk factors and implementing preventive measures is essential,” Dr. Bo noted in the study’s press release. (*Source: Medical News Today)
Biological Age and Brain Health: The Connection Explained
Observable Brain Changes
One of the most compelling aspects of the study was the identification of specific brain changes associated with advanced biological age. Researchers discovered that participants with higher biological age showed measurable structural differences in their brains, including:
- Reduced gray matter volume
- Changes in cortical thickness
- Alterations in brain surface area
Gray matter plays a crucial role in cognitive function, including memory, decision-making, and information processing. Previous research has linked gray matter volume loss with increased risk for Alzheimer’s disease and other forms of dementia.
The Causation Question
While the study demonstrates a clear association between advanced biological age and dementia risk, researchers caution that it does not prove causation. However, Dr. Bo and colleagues suggest that “advanced biological age may contribute to the development of dementia by causing a widespread change in brain structures.”
These brain structure changes explain some—but not all—of the link between biological aging and dementia, indicating that multiple mechanisms are likely involved in this complex relationship.
The Global Impact of Dementia
Current Statistics and Future Projections
Dementia represents a growing global health challenge:
- More than 6 million Americans currently live with dementia
- Approximately 100,000 deaths annually in the US are attributed to dementia
- Globally, 55 million people were living with dementia in 2020
- This number is projected to reach 78 million by 2030
- By 2050, global dementia cases could reach 139 million
Despite a 13% decline in dementia rates per decade due to improved education, heart health, and lifestyle factors, the total number of cases continues to rise as the population ages, placing increasing pressure on healthcare systems worldwide.
The Economic and Social Burden
The impact of dementia extends far beyond individual health concerns:
- Caregiving demands place enormous strain on families
- Healthcare costs for dementia care are substantial and growing
- Productivity losses affect the broader economy
- Social isolation affects both patients and caregivers
These factors underscore the urgency of identifying effective prevention strategies and interventions.
Slowing Biological Aging: Practical Approaches
Lifestyle Modifications
Research suggests several evidence-based approaches to potentially slow biological aging:
Physical Activity
Regular exercise has been consistently linked to lower biological age and reduced dementia risk. Recommendations include:
- At least 150 minutes of moderate-intensity aerobic activity weekly
- Muscle-strengthening activities at least twice weekly
- Reducing sedentary time throughout the day
Dietary Patterns
Nutritional approaches associated with healthier biological aging include:
- Mediterranean Diet: Rich in fruits, vegetables, whole grains, fish, olive oil, and limited red meat
- MIND Diet: Combines Mediterranean and DASH diet principles, specifically targeted at neural health
- Maintaining adequate hydration
- Limiting processed foods, added sugars, and excessive alcohol
Dr. Rehan Aziz, a geriatric psychiatrist at Jersey Shore University Medical Center, emphasizes: “A nutritious diet rich in fruits, leafy green vegetables, whole grains, and lean proteins can help control cholesterol levels, reduce inflammation, and lower blood pressure.” (*Source: Medical News Today)
Sleep Quality
Optimizing sleep may help maintain a more youthful biological age:
- Aiming for 7-8 hours of quality sleep nightly
- Maintaining consistent sleep-wake cycles
- Addressing sleep disorders promptly
Stress Management
Chronic stress accelerates biological aging through multiple pathways:
- Regular mindfulness or meditation practice
- Spending time in nature
- Nurturing social connections
- Pursuing meaningful activities and hobbies
Medical Monitoring and Management
Regular medical care plays a vital role in managing biological age:
- Consistent monitoring of key biomarkers like blood pressure and cholesterol
- Proper management of chronic conditions
- Preventive screenings appropriate for age and risk factors
- Medication adherence when prescribed
Dr. Cheng-Han Chen, a board-certified interventional cardiologist, notes: “To help improve overall health and potentially reduce the risk of developing dementia, we recommend that people engage in regular physical activity, eat a healthy balanced diet, get an adequate amount of quality sleep, maintain a healthy weight, avoid tobacco and alcohol, reduce their stress, maintain strong social connections, and control their blood pressure and cholesterol numbers.” (*Source: Medical News Today)
Biological vs. Chronological Age: Key Differences
The following table summarizes the fundamental distinctions between biological and chronological age:
| Aspect | Chronological Age | Biological Age |
|---|---|---|
| Definition | Years since birth | Physiological state of the body |
| Measurement | Calendar date | Biomarkers (e.g., blood pressure, lung function) |
| Variability | Constant across individuals of the same birth date | Varies based on genetics, lifestyle, environment |
| Modifiability | Cannot be changed | Can be influenced by lifestyle and medical interventions |
| Health Prediction | Limited correlation with health status | Stronger predictor of disease risk and mortality |
| Assessment Methods | Birth certificate, ID documents | Blood tests, physiological measurements, and advanced algorithms |
| Relevance to Dementia | Less predictive than biological age | 30% increased risk when advanced beyond chronological age |
| Clinical Application | Used for basic health screening timing | Emerging tool for personalized risk assessment |
Future Directions in Research and Clinical Practice
Emerging Research
The connection between biological aging and dementia opens several promising research directions:
- Development of standardized, accessible biological age testing
- Investigation of interventions specifically targeting biological age reduction
- Exploration of sex-specific factors in biological aging
- Integration of genetic risk factors with biological age assessment
- Longitudinal studies examining whether biological age reduction translates to dementia risk reduction
Dr. John Thomson Smith, senior medical advisor at AI-powered longevity research network Rejuve AI, highlights the potential: “Focusing on biological age offers a more accurate, personalized understanding of an individual’s health. In clinical settings, this could guide more tailored treatment plans, while in consumer wellness, it could provide personalized wellness recommendations to improve quality of life and longevity.” (*Source: Decrypt)
Clinical Applications
Healthcare providers are increasingly interested in incorporating biological age assessment into clinical practice:
- Early identification of individuals at higher dementia risk
- More personalized prevention recommendations
- Potentially earlier intervention in high-risk individuals
- Monitoring the effectiveness of lifestyle modifications
- Integration with other risk assessment tools
Dr. Aziz notes that “the next steps I’d like to see include conducting longitudinal studies to examine whether specific interventions targeted at reducing biological age (like targeted diet, exercise, or medications) can actually decrease the incidence of dementia and actually improve biological age scores. The development of standardized clinical tools for easy measurement of biological age in routine medical practice could also help to enable real-time clinical discussions and tailored patient recommendations.” (*Source: Medical News Today)
Conclusion: Reframing Aging and Dementia Risk
The groundbreaking research linking biological age to dementia risk offers a paradigm shift in how we understand aging and disease prevention. While chronological age remains a fixed aspect of human existence, biological age represents a dynamic, modifiable factor that may significantly influence neurological health outcomes.
The finding that individuals with advanced biological age face approximately 30% higher dementia risk underscores the importance of addressing modifiable factors throughout the lifespan. Regular physical activity, nutritious dietary patterns, quality sleep, stress management, and consistent medical monitoring represent practical approaches to potentially slow biological aging processes.
As research continues to evolve, biological age assessment may increasingly become an integral component of personalized healthcare, enabling more targeted interventions for those at heightened dementia risk. The emerging understanding of how biological aging affects brain structure offers promising avenues for developing novel preventive strategies and therapeutic approaches.
By recognizing that age is more than just a number on a calendar, individuals and healthcare providers can work together to promote healthier aging trajectories and potentially reduce the growing global burden of dementia. As Dr. Bo aptly noted in the study’s conclusion, “While none of us can change our chronological age, we can influence our biological age through lifestyle factors such as diet and exercise.”
Frequently Asked Questions (FAQs)
Chronological age is the number of years since birth, while biological age reflects how well the body’s systems are functioning based on various biomarkers like blood pressure, lung function, and cholesterol levels.
Researchers use methods such as the Klemera-Doubal Method Biological Age (KDM-BA) and PhenoAge, which analyze biomarkers including lung function, blood pressure, cholesterol, blood cell metrics, and other indicators of physiological health.
Biological age provides a more accurate picture of overall health status and disease risk because it reflects how well the body is actually functioning rather than simply counting years lived.
Yes, unlike chronological age, biological age can be influenced through lifestyle modifications including diet, exercise, sleep quality, stress management, and proper medical care.
Advanced biological age is associated with reduced gray matter volume, changes in cortical thickness, and alterations in brain surface area—all of which are linked to increased dementia risk.
The study found that individuals with the most advanced biological age were approximately 30% more likely to develop dementia compared to those with the lowest biological age.
Research indicates potential sex differences in biomarkers as people age and go through hormonal changes like menopause, though more studies are needed to fully understand these differences.
Advanced biological aging may contribute to dementia through multiple pathways including chronic inflammation, oxidative stress, impaired cellular repair mechanisms, mitochondrial dysfunction, and compromised cerebrovascular health.
Genetic risk factors like APOEε4 may accelerate certain aspects of biological aging, particularly those related to brain health. Research shows APOEε4 carriers had higher levels of specific biomarkers including phosphorylated tau 181 and glial acidic proteins.
Current methods face challenges including standardization across populations, limited understanding of how specific biomarkers interact with environmental factors, potential selection bias in research cohorts, and the need for longitudinal validation to confirm predictive accuracy over time.