Older adults' driving habits may offer early clues about brain health and cognitive decline, according to preliminary research presented at the American Stroke Association's International Stroke Conference 2026. The study, which followed 220 adults aged 65 and older over five years, 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.
"Driving habits in older adults can reveal early changes in brain health. How often people drive, where they go, and how much they vary their routes may signal underlying damage to the brain's white matter, which is linked to cognitive decline and dementia," said study author Chia-Ling Phuah, M.D., M.M.Sc., an associate professor of neurocritical care and co-director of the Neuro Analytics Center at Barrow Neurological Institute in Phoenix.
Researchers used car sensors to track driving behavior, including speeding, collisions, hard braking, and hard cornering, over more than five years. Brain imaging within the first year measured white matter hyperintensities—areas of damage caused by reduced blood flow. The analysis revealed that older adults with more white matter hyperintensities tended to drive less and showed sharper declines in their willingness or ability to change driving routes and habits. Over the follow-up period, 17% of participants developed cognitive impairment, most diagnosed with Alzheimer's disease.
Among those with cognitive impairment, higher white matter hyperintensity burden was linked to unsafe driving practices, such as hard braking, and more crashes. Notably, damage in the back part of the brain, which helps process visual information and coordinate 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, making them more likely to experience unsafe driving episodes and car accidents over time," Phuah explained.
Interestingly, participants taking blood pressure medications, especially angiotensin-converting enzyme (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. This effect was observed regardless of whether their blood pressure levels were at target levels," Phuah said. "This suggests that 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 in people with white matter disease requires further investigation."
The study's limitations include a small sample size, with most participants being white and college-educated, and medication use was self-reported. Larger, more diverse studies are needed to confirm these findings. The research was part of the Driving Real-World In-Vehicle Evaluation System (DRIVES) project based at Washington University in St. Louis, with data collected from 2016 to 2024.
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. The findings underscore that subtle changes in everyday driving habits may serve as early warning signs of brain changes and higher dementia risk, sometimes before traditional memory and thinking symptoms appear.
