Higher Biological Age Associated with Increased Dementia Risk, Study Reveals

A recent extensive study published in the journal Neurology reveals a significant correlation between biological age and the risk of developing dementia. The research indicates that individuals with a biological age that exceeds their chronological age face a higher likelihood of dementia compared to those whose biological age aligns with or is lower than their chronological age. Biological age is determined by various aging biomarkers, including lung function, blood pressure, and cholesterol levels.

While this study establishes a link between advanced biological age and dementia risk, it does not confirm that an increased biological age directly causes dementia. As noted by researchers, understanding risk factors and implementing preventative strategies is crucial given the growing prevalence of dementia globally. Factors influencing biological age, which can be modified through lifestyle changes such as diet and physical activity, are of particular interest.

The study analyzed data from 280,918 participants within a United Kingdom database, all of whom were dementia-free at the outset and had an average chronological age of 57. Over an average follow-up period of 14 years, 4,770 participants developed dementia.

To assess biological age, researchers employed two distinct methodologies, which included evaluating lung function, blood pressure, cholesterol levels, and additional blood biomarkers like average cell volume and white blood cell count. These measurements provided insights into the interrelated functioning of various bodily systems--metabolism, immunity, and organ health--as they age.

Notably, among those who subsequently developed dementia, the average chronological age was 65 at the start of the study, contrasting with 57 for participants who remained dementia-free. However, their average biological age was recorded as 55, while those without dementia had an average biological age of 45.

When stratified into four categories based on biological age, participants with the most advanced biological age exhibited approximately a 30% higher risk of developing dementia compared to those in the lowest category. These findings were adjusted to account for additional variables that could influence dementia risk, such as educational attainment and smoking habits.

The research also identified structural brain changes linked to dementia in individuals with higher biological ages, including reductions in gray matter volume. These changes may elucidate some, but not all, of the relationship between elevated biological age and dementia, supporting the theory that advanced biological age might lead to widespread changes in brain architecture.

However, it is essential to acknowledge a limitation of the study: the participant population generally exhibits higher health consciousness, which could result in a lower likelihood of developing dementia compared to the broader population.

This research underscores the importance of understanding biological age dynamics and their potential impact on cognitive health as society continues to confront the challenges posed by dementia.