Imagine going to the doctor and getting your blood pressure checked. You know, the machine that squeezes your arm and then shows two numbers?
Most people know that these numbers are important for heart health. But now, scientists are discovering that one of these numbers might also give us clues about how healthy our brain is.
A team of researchers from the University of Miami, led by Michelle R. Caunca, published a study in the journal Stroke. Their work looked at the second number from the blood pressure test – the one called diastolic blood pressure. This number measures the pressure in your arteries when your heart is resting between beats. It’s usually the smaller number of the two.
Doctors usually focus more on the first number, called systolic blood pressure, because it’s linked to heart attacks and strokes. But this study showed that the diastolic number might be just as important, especially when it comes to brain health.
The researchers studied 1,205 adults aged 50 and older. They used MRI scans to check for tiny scars in the brain called white matter lesions. These scars are not something you can feel, but they can cause big problems. They can affect memory, thinking, movement, and even increase the risk of falling or having a stroke.
Here’s what they found: People who had lower diastolic blood pressure—below 80—had fewer of these brain scars. But people with higher diastolic blood pressure—above 90—had more of these scars. That means having a higher number might be quietly harming your brain over time.
White matter is the part of the brain that helps messages travel between different areas. When white matter gets damaged, those messages don’t travel properly. This can make it harder to think clearly, remember things, or move around safely.
By age 60, up to one in five people may already have these white matter scars, and they become even more common as we age. By the time people are over 90, most of them will have some white matter damage.
The study also showed that where these scars appear in the brain matters. In particular, scars in the periventricular region—a deep part of the brain—are more likely to cause memory and thinking problems.
So what should we take from this? It means we should pay attention to both blood pressure numbers, not just the top one. It also reminds us to talk to our doctors about what our blood pressure numbers mean for our overall health—including our brain.
Keeping that lower number in a healthy range might be one simple way to protect your brain as you get older. It’s a small number that could make a big difference.
If you care about high blood pressure, please read studies about unhealthy habits that may increase high blood pressure risk, and drinking green tea could help lower blood pressure.
For more information about high blood pressure, please see recent studies about what to eat or to avoid for high blood pressure, and 12 foods that lower blood pressure.
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