Public Health

Area of Science:

• Neuroscience
• Gerontology
• Public Health

Background:

• Cognitive reserve (CR) and brain maintenance (BM) are key to preserving cognitive function with aging and disease.
• Physical activity is a potential pathway to BM and CR, but mechanisms linking fitness to brain health are unclear.

Purpose of the Study:

• To investigate the association between physical fitness and brain pathology in older adults.
• To examine if physical fitness moderates the impact of brain pathology on cognitive performance.

Main Methods:

• 167 cognitively unimpaired older adults underwent assessments of cognitive performance, aerobic capacity (VO2max), and muscular capacity.
• Collected biomarkers included plasma Alzheimer's markers, serum plasticity markers, and PET/MRI measures of brain pathology (e.g., medial temporal lobe tau, white matter hyperintensities, perivascular spaces).

Main Results:

• Higher aerobic capacity correlated with lower basal ganglia perivascular space volumes and better global cognition.
• Medial temporal lobe tau burden was associated with poorer verbal memory.
• No significant associations were found between physical fitness and Alzheimer's or plasticity biomarkers, or hippocampal volume.

Conclusions:

• Aerobic fitness is associated with reduced cerebrovascular burden (perivascular spaces) and may act as a cognitive reserve proxy against medial temporal lobe tau pathology.
• Physical fitness may help maintain brain structure and function, potentially mitigating age-related cognitive decline.