Does Your Biological Age Affect Your Risk of Dementia?

People whose biological age is higher than their chronological age may develop dementia more often than people whose biological age is the same as or lower than their chronological age. This is according to a study published online in Neurology^®, the medical journal of the American Academy of Neurology. Biological age is based on biomarkers of aging such as lung function, blood pressure, and cholesterol. The study does not prove that advanced biological age causes dementia, but merely shows a correlation.

Chronological Versus Biological Age

Chronological age does not necessarily correspond to biological age. Chronological age refers to the number of years that have passed since birth, i.e., how old a person actually is. Biological age, on the other hand, defines the condition of the body, i.e., how healthy a person is or what physical limitations they have. A definition could therefore be that biological age shows the true condition of the body. The functionality of important systems, including the cardiovascular and immune systems, metabolism, and cell aging, plays a significant role in this. Many factors can influence biological age, such as personal lifestyle, stress, and genetic conditions. A person who maintains a healthy lifestyle may therefore be biologically younger than their chronological age suggests. Conversely, unhealthy habits can increase biological age.

People With the Highest Biological Age Had an Approximately 30% Higher Risk of Developing Dementia

“Given the growing global importance of dementia, it is essential to identify risk factors and take preventive measures,” said the study’s author, Dr. Yacong Bo of Zhengzhou University in China. ”While no one can change their chronological age, we can influence our biological age through lifestyle factors such as diet and exercise.” The study involved 280,918 people from a British database who had an average age of 57 at the start of the study and did not have dementia at that time. They were followed for an average of 14 years. During this time, 4,770 people developed dementia.

The researchers used two methods to measure biological age. In addition to lung function, blood pressure, and cholesterol levels, other biomarkers in the blood were measured, such as average cell volume and white blood cell count. These methods show how different parts of the body, such as metabolism, immunity, liver, kidneys, heart, and other systems, work together as we age. While people who developed dementia later in life had an average chronological age of 65 at the start of the study, compared to 57 for those who did not develop dementia, their average biological age according to one of the methods was 55, compared to 45 for people without dementia.

When dividing participants into four groups based on their biological age, the researchers found that those with the highest biological age had a roughly 30% higher risk of developing dementia than those in the lowest group. These results were adjusted for other factors that could influence dementia risk, such as age, education level, and smoking status. The researchers also found that people with advanced biological age also had changes in the brain associated with dementia, such as a loss of gray matter. “These changes in brain structure explain some, but not all, of the links between advanced biological age and dementia,” Bo said. These findings support the hypothesis that advanced biological age may contribute to the development of dementia through widespread changes in brain structures. One limitation of the study is that participants in the database tend to be more health-conscious than the general population and may therefore be less susceptible to dementia.