Scientists at the University of Miami have made an important discovery: a part of your blood pressure reading that many people overlook could actually help doctors understand your risk for serious brain problems.
This part is called the diastolic blood pressure — it’s the lower number in a blood pressure test.
This new research shows that this number might offer important clues about brain health, especially when it comes to the risk of strokes, memory problems, or dangerous falls in older adults.
To understand why this matters, let’s first look at what blood pressure actually is. Blood pressure is measured using two numbers. The top number, called systolic pressure, shows how hard your heart is pushing blood through your arteries when it beats.
The bottom number, called diastolic pressure, shows the pressure when your heart is resting between beats. Most doctors pay close attention to the top number because it is strongly linked to heart disease. But now, scientists are realizing that the bottom number matters too — especially for your brain.
In this study, researchers looked at more than 1,200 people who were 50 years old or older. They checked their blood pressure and took MRI scans of their brains.
They were especially interested in finding white matter lesions — small damaged areas in the brain that can interrupt how signals move between different parts of the brain. These lesions are known to increase the chances of memory loss, trouble walking, and strokes.
What the scientists found was surprising. People with lower diastolic blood pressure — below 80 — had fewer of these white matter lesions. On the other hand, people with higher diastolic pressure — above 90 — had more brain damage. This suggests that keeping the bottom blood pressure number in a healthy range might help protect the brain.
We already knew that having high systolic blood pressure (the top number) can narrow the arteries and hurt the brain. But this study shows that high diastolic pressure (the bottom number) may also play a harmful role. It especially affects parts of the brain that help us think clearly and remember things.
White matter is like the communication cables in your brain. It helps different parts of the brain send messages to each other. When this white matter is damaged, those messages don’t get through as well. That’s when people may start to have trouble with balance, memory, or even simple daily tasks.
According to the American Heart Association, white matter lesions are already found in 10 to 20 percent of people by the time they are 60 years old. In people over 90, they are very common. That’s why this study is so important. It could help doctors spot risks earlier and find better ways to prevent brain damage before it leads to more serious problems.
This study was led by Dr. Michelle Caunca and published in the journal Stroke. The scientists believe that paying more attention to the lower blood pressure number could give doctors another tool to help protect brain health as people age.
They suggest that people should regularly check their blood pressure and talk to their doctors about what those numbers mean — both the top and the bottom.
If you care about blood pressure, please read studies that changing blood pressure readings is a hidden sign of heart disease and switching blood pressure drugs may treat the condition better.
For more health information, please read studies about the arm squeeze test: could your blood pressure reading be wrong and bedtime medication more effective for high blood pressure.
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