A recent international study has provided new insights into how structural changes in the brain are linked to memory decline as people age. The research analyzed more than 10,000 MRI scans and over 13,000 memory assessments from 3,700 cognitively healthy adults who participated in 13 separate studies.
The study found that the connection between shrinking brain tissue and declining memory is not straightforward. It is stronger in older adults and does not appear to be solely influenced by genes commonly associated with Alzheimer's disease, such as APOE ε4. These results indicate that the process of brain aging involves multiple factors and affects several regions of the brain.
Published in Nature Communications under the title "Vulnerability to memory decline in aging revealed by a mega-analysis of structural brain change," the research concluded that memory decline is related to widespread changes across many parts of the brain rather than being limited to one area. While the hippocampus showed the strongest link between volume loss and reduced memory performance, other cortical and subcortical regions also played significant roles. This suggests that cognitive decline reflects a broader vulnerability throughout much of the brain.
The study also reported that the relationship between regional brain atrophy and memory loss varies among individuals and follows a nonlinear pattern. People with higher rates of structural loss experienced greater declines in memory, indicating that once brain shrinkage reaches a certain point, cognitive effects become more pronounced. This trend was seen across various brain regions.
"Cognitive decline and memory loss are not simply the consequence of aging, but manifestations of individual predispositions and age-related processes enabling neurodegenerative processes and diseases. These results suggest that memory decline in aging is not just about one region or one gene - it reflects a broad biological vulnerability in brain structure that accumulates over decades. Understanding this can help researchers identify individuals at risk early, and develop more precise and personalized interventions that support cognitive health across the lifespan and prevent cognitive disability."
The research team included scientists from institutions such as the University of Oslo, Danish Research Centre for Magnetic Resonance, University of Barcelona, Max Planck Institute for Human Development, University of Milan, University of Geneva, University of Cambridge, Umeå University, Oslo University Hospital, among others.
