Scientists from the University of Miami have made an important discovery about blood pressure and brain health.
Their new study shows that the lower number in a blood pressure reading—called diastolic blood pressure—may be just as important as the top number when it comes to protecting the brain from damage that can lead to memory problems, strokes, or even dangerous falls.
Blood pressure is measured using two numbers. The top number is called systolic blood pressure. It shows how much pressure is in the arteries when the heart is beating. The bottom number is called diastolic blood pressure, which shows the pressure in the arteries when the heart is resting between beats.
Most doctors focus on the top number to check for heart disease, but this new research suggests that the bottom number might also play a big role, especially in keeping the brain healthy as we age.
The study looked at 1,205 people who were 50 years old or older. The researchers measured their blood pressure and also examined their brains using MRI scans.
They were searching for tiny scars in the brain called white matter lesions. These lesions can interrupt how the brain sends and receives messages, leading to trouble with thinking, memory, walking, and balance.
The results showed that people with lower diastolic blood pressure—under 80—had fewer of these white matter lesions than people with high diastolic pressure—above 90. This means that having high diastolic pressure could lead to more brain damage over time.
It was already known that high systolic blood pressure (the top number) could lead to narrowed arteries, which also contributes to these brain lesions. But this new research adds that the diastolic number matters too—especially in brain areas linked to memory and thinking.
White matter in the brain is made up of nerve fibers that allow different parts of the brain to communicate. When white matter lesions form, that communication breaks down. This can lead to problems like confusion, memory loss, or a higher chance of falling.
The American Heart Association says that about 10 to 20% of people have white matter lesions by the age of 60. These lesions become even more common in people over 90.
The new study suggests that by keeping an eye on both systolic and diastolic blood pressure, doctors might be able to spot people at higher risk for brain damage earlier. This could be especially important for a type of brain lesion called periventricular white matter lesions, which are strongly linked to memory loss and cognitive decline.
Different parts of the brain get blood from different arteries. That means high blood pressure can affect each area of the brain in unique ways. By learning more about how this works, scientists hope to find better ways to prevent strokes and dementia.
The researchers, led by Michelle R. Caunca, say it’s important for everyone to know their blood pressure numbers and to talk to their doctor about the best ways to manage them. This study was published in the journal Stroke and could lead to new ways to protect brain health in the future.
If you care about stroke, please read research about Research finds a better high blood pressure treatment for stroke patients and findings of Scientists find a better drug than statins for stroke patients.
For more about stroke, please read studies about Half of people with heart rhythm diseases dying of heart attack, stroke and findings of New method reduces heart attacks and strokes over five years.
Copyright © 2025 Knowridge Science Report. All rights reserved.
