Older adults' driving habits can offer early clues about brain health and cognitive decline, according to a preliminary study to be presented at the American Stroke Association's International Stroke Conference 2026. The research, involving 220 adults aged 65 and older, tracked driving behavior over more than five years and found that greater white matter damage in the brain was associated with decreased driving, fewer trips, repetitive routes, and more driving errors, particularly among those who later developed dementia.
White matter hyperintensities, areas of damage caused by reduced blood flow to brain tissue, were measured using MRI scans. The study found that participants with more white matter damage tended to drive less and showed sharper declines in their willingness or ability to vary driving routes. Over the follow-up period, 17% of participants developed cognitive impairment, most diagnosed with Alzheimer's disease. Among these individuals, higher white matter burden was linked to unsafe driving practices such as hard braking and more crashes.
Notably, white matter damage in the back part of the brain, which processes visual information and coordinates movement, was most strongly tied to unsafe driving and crashes. “Participants with white matter hyperintensities located in the back of the brain were at even higher risk of crashes than those with changes in other brain areas,” said study author Chia-Ling Phuah, M.D., M.M.Sc., an associate professor at Barrow Neurological Institute.
However, the study also revealed a protective effect: participants taking blood pressure medications, especially ACE inhibitors, were less likely to exhibit risky driving behaviors even when brain damage was present. “One especially promising finding was that people taking blood pressure medications, particularly ACE inhibitors, tended to maintain safer driving habits even when their brain scans revealed more damage,” Phuah noted. This effect was observed regardless of whether blood pressure levels were at target, suggesting these medications may help support brain health as we age.
Nada El Husseini, M.D., M.H.Sc., FAHA, chair of the American Heart Association's 2023 scientific statement on cognitive impairment after stroke, commented, “What's surprising about these findings is that people taking ACE inhibitors were less likely to have impairment in their driving despite the extent of white matter disease. The impact of ACE inhibitors on cognitive function and driving safety requires further investigation.”
The study, part of the Driving Real-World In-Vehicle Evaluation System (DRIVES) project at Washington University in St. Louis, used car sensors to track driving behavior including speeding, collisions, hard braking, and hard cornering. Participants underwent annual cognitive assessments and brain imaging. The findings suggest that monitoring driving behavior with commercial in-vehicle data loggers may help identify older adults at higher risk for unsafe driving and subtle cognitive problems.
Key limitations include a small sample size, with most participants being white and college-educated, limiting generalizability. Medication use was self-reported, which could introduce errors. Larger, more diverse studies are needed to confirm these findings.
According to the American Heart Association 2026 Heart and Stroke Statistics, about 6.9 million adults 65 or older in the U.S. were living with Alzheimer's disease in 2024. This study underscores the potential of everyday driving habits as early indicators of brain health changes, offering a window into cognitive decline before traditional symptoms appear.
