Association between driving a car and retention of brain volume in Japanese older adults

Background: Driving cessation is a major negative life event that has been associated with a decline in health conditions including dementia. The increase in activity owing to the expansion of life space is a possible explanation for the positive relationship between driving and brain health. The present study examined the association between driving, life space, and structural brain volume in older individuals. Methods: High-resolution magnetic resonance imaging was employed to examine the brain volume in 1063 older adults. Participants were classified as non-drivers, those who drove <7 days a week, and everyday drivers. They were further classified into a non-driving group, an active group (drove 10 km at least once a week), and a less-active group (drove 10 km less than once a week). Results: The hippocampal volume was greater in drivers than in non-drivers. Occipital cortex volume was greater in low-frequency drivers than in non-drivers and high-frequency drivers. Active drivers exhibited larger temporal cortex volumes than less-active drivers, larger cingulate cortex volumes than non-drivers and less-active drivers, and larger hippocampal volumes than non-drivers. Conclusion: Driving was associated with hippocampal brain atrophy attenuation, with active drivers exhibiting decreased brain atrophy in the temporal and cingulate cortices.