Turns out, older people who have higher blood pressure may have more signs of brain disease, specifically brain lesions.
Researchers also found a link between higher blood pressure and Alzheimer's.
Study author Zoe Arvanitakis said, "Blood pressure changes with aging and disease, so we wanted to see what kind of impact it may have on the brain."
He added, "We researched whether blood pressure in later life was associated with signs of brain aging that include plaques and tangles linked to Alzheimer's disease, and brain lesions called infarcts, areas of dead tissue caused by a blockage of the blood supply, which can increase with age, often go undetected and can lead to stroke."
Healthy blood pressure is less than 120/80 millimeters of mercury (mmHg). High blood pressure is above 140/90 mmHg. The higher number is called systolic blood pressure, the pressure in the blood vessels when the heart beats.
The lower number is called diastolic blood pressure, the pressure when the heart is at rest.
Researchers found that the risk of brain lesions was higher in people with higher average systolic blood pressure across the years.
The results did not change when researchers controlled for other factors that could affect the risk of brain lesions, such as whether they used high blood pressure drugs.
When looking for signs of Alzheimer's disease in the brain at autopsy, researchers found a link between higher average late-life systolic blood pressure across the years before death and a higher number of tangles, but not plaques.
However, the limitations of the study include that researchers did not have access to the blood pressure of participants in middle age, only in later life, and that blood pressure information was recorded only once a year and not more frequently.
The full findings are published in the journal- Neurology.