New study discovers how biological age affects dementia risk

• The impact of biological age: Findings from a new study highlight an association with advanced biological age and an increased risk of dementia. 

• Estimating biological age: The researchers analyzed data from nearly 300,000 adults with an average age of 57 and utilized two different methods of biological age estimation to understand the connection with dementia. 

• Changes to the brain: The study found that those with the oldest biological age had a 30% higher risk of dementia, and scans also showed changes to their brain structure consistent with dementia.   

A new study conducted by the American Academy of Neurology explored how biological age, versus chronological age, can impact dementia risk. 

Their work found an association between those with a higher biological age and a higher risk of developing dementia. 

“With the rising impact of dementia around the world, identifying risk factors and implementing preventive measures is essential,” study author Yacong Bo, Ph.D., said in a news release. 

“While none of us can change our chronological age, we can influence our biological age through lifestyle factors such as diet and exercise.”

The study

The researchers analyzed data from over 280,000 participants with an average age of 57 enrolled in the U.K. Biobank. The participants were followed for an average of 14 years, and none of them had any history of cognitive decline or dementia when the study began. 

From there, the researchers calculated each participant’s biological age using two method: 

• The Klemera-Doubal method biological age (KDM-BA): This method uses biomarkers in the blood, like white blood cell count and average cell volume to estimate biological age. 

• PhenoAge Algorithms: An algorithm that uses specific biometrics, including lung function, blood pressure, and cholesterol, to estimate biological age. 

The team also evaluated the participants’ brain health and function, and incorporated genetic risk factors of dementia, to assess cognition throughout the study. 

Biological age plays a role

The researchers divided the participants into four groups based on their biological age, and they learned that advanced biological age was associated with a higher risk of dementia. 

Those with the oldest biological age had a 30% higher risk of developing dementia compared to those with the youngest biological age. 

On top of that, higher biological age was associated with changes in brain structure that are closely linked with Alzheimer’s. These participants were more likely to have less gray matter – the outer layer of the brain that controls thinking, learning, memory, motor control, and decision-making. 

“These brain structure changes explain some, but not all, of the association between advanced biological age and dementia,” Dr. Bo said. “These results support the hypothesis that advanced biological age may contribute to the development of dementia by causing a widespread change in brain structures.”