Research Highlights:
- A study of over 200 adults followed for five years found that greater white matter damage in the brain was linked to decreased driving, fewer trips, repetitive routes and having more driving errors, especially in those who later developed dementia.
- In contrast, adults ages 65 and older who were taking blood pressure medicines, particularly ACE inhibitors, were less likely to show risky driving behaviors, even when brain damage was present (evidence of white matter damage caused by reduced blood flow to brain tissue).
- Subtle changes in everyday driving habits may be early warning signs of brain changes and higher dementia risk, even before traditional memory and thinking symptoms appear, the researchers noted.
- White matter damage in the back part of the brain, which helps people process what they see and coordinate movement, was most strongly tied to unsafe driving and crashes, pointing to a potential early warning marker for higher driving risk in older adults.
- Note: The study featured in this news release is a research abstract. Abstracts presented at the American Heart Association/American Stroke Association's scientific meetings are not peer-reviewed, and the findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
DALLAS, Jan. 29, 2026 — Older adults' driving habits revealed clues about their brain health and may provide early warning signs of cognitive decline or dementia, according to a preliminary study to be presented at the American Stroke Association's International Stroke Conference 2026. The meeting is in New Orleans, Feb. 4-6, 2026, and is a world premier global event dedicated to advancing stroke and brain health science.
"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. "These findings suggest that even small shifts in daily driving patterns can offer important clues about brain changes — sometimes before traditional memory and thinking symptoms are noticeable."
According to the American Heart Association 2026 Heart and Stroke Statistics, about 6.9 million (10.9%) – or 1 in 9 - adults 65 years or older in the United States were living with Alzheimer's disease in 2024.
Researchers reviewed driving habits for 220 adult volunteers, ages 65 and older, living independently in St. Louis, Missouri. Detailed cognitive assessments indicated participants were free of dementia at the start of the study. Car sensors were used to track participants' driving behavior (including speeding, collisions, hard braking or hard cornering) for more than five years. They conducted additional brain imaging studies within the first year of the study to measure changes in the brain's white matter, specifically white matter hyperintensities — areas of white matter damage caused by reduced blood flow to brain tissue.
The analysis found:
- Older adults who had more white matter hyperintensities tended to drive less and show sharper declines in their willingness or ability to change driving routes and habits.
- Over more than five years of follow-up, 17% of participants developed cognitive impairment and most of these individuals were later diagnosed with Alzheimer's disease.
- Among the 17% of participants who developed cognitive impairment, higher white matter hyperintensity burden on brain imaging was linked to a greater likelihood of unsafe driving practices, such as hard braking, and to more crashes.
- "Participants with white matter hyperintensities located in the back of the brain — a region responsible for processing what people see and how they move — 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.
- Participants taking medications to manage high blood pressure, especially angiotensin-converting enzyme (ACE) inhibitors, were less likely to exhibit risky driving when compared with those who were not taking any blood pressure medication.
Overall, the study's findings suggest that monitoring driving behavior with commercial in-vehicle data loggers may help identify older adults at higher risk for unsafe driving, loss of independence and subtle cognitive problems, Phuah noted.
"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, Cognitive Impairment After Ischemic and Hemorrhagic Stroke said, "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. Also, these results suggest cognitive screening and brain imaging might be considered for people with driving difficulties." El Husseini is an associate professor of neurology at Duke University Medical Center in Durham, North Carolina and was not involved in this study.
Normal blood pressure is less than 120/80, and treatment is recommended for people with blood pressure levels 140/90 mm Hg or higher (stage 2 hypertension). Recent research confirms that blood pressure affects brain health, including cognitive function and dementia, so early treatment is recommended for people diagnosed with high blood pressure to maintain brain health and cognition, according to the 2025 American Heart Association High Blood Pressure Guideline.
Key limitations include a small study size, most participants were white, college-educated adults, so results may not generalize to people from more diverse backgrounds, and medication use was self-reported, which could introduce errors.
The next step will be larger studies that include more diverse participants to confirm and extend these findings.
Study details, background and design:
- The study included 220 adults (average age of 73 years; 54% men, 46% women, 88% white and 12% Black) living in St. Louis, Missouri, who did not have dementia when they enrolled in the study.
- Data was collected over a nine-year period, from 2016 to 2024, as part of the Driving Real-World In-Vehicle Evaluation System (DRIVES) project based at Washington University in St. Louis.
- Participants were monitored for continuous in-vehicle driving metrics, such as trip frequency, distance and destination, as well as safety events, including time spent speeding, collisions, hard braking or hard cornering.
- All participants had brain magnetic resonance imaging (MRI) scans to measure white matter hyperintensities at enrollment, which was around the time they started their driving assessments. About half (102 participants) had a second MRI scan at least 12 months after their first scan. Participants also underwent annual clinical and cognitive assessments.
- Researchers analyzed the relationship between total and regional white matter hyperintensities and driving patterns and safety.
- Statistical models were used to adjust for demographics, social/economic factors and health factors.
Patient perspective: A caregiver's view of driving and cognitive decline
For Larry Duncan, a retired business owner from Pinehurst, North Carolina, driving was part of his independence. But subtle changes began to appear before his Alzheimer's diagnosis in 2023. "Larry was fine driving in familiar areas," recalls his wife and caregiver, Pam Duncan. "But in new places where he had to make quick decisions, he became anxious."
As his cognitive challenges progressed, Duncan's doctor advised him to stop driving, a decision she describes as heartbreaking but necessary.
"In early-stage cognitive impairment, symptoms can be subtle, and driving is one of them," said Pam Duncan, who now volunteers for the American Stroke Association, a division of the American Heart Association. "Don't ignore these changes. As caregivers, our role is to support independence while having the courage to make tough decisions. You can live well with dementia, but it starts with awareness and action."
Co-authors, disclosures and funding sources are listed in the abstract.
Statements and conclusions of studies that are presented at the American Heart Association/American Stroke Association's scientific meetings are solely those of the study authors and do not necessarily reflect the Association's policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association's scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.
