Scientists at the University of Miami have found an important clue that could help us understand how blood pressure affects the aging brain.
Their recent research suggests that the lower number in a blood pressure reading, called the diastolic pressure, may help predict a person’s risk of developing brain damage linked to dementia, strokes, memory loss, or even falls. This finding could change how doctors think about blood pressure and brain health.
Blood pressure is measured using two numbers. The top number is the systolic pressure, and it shows how much force the blood pushes against artery walls when the heart beats. The bottom number is the diastolic pressure, which shows the pressure inside the arteries when the heart is resting between beats.
For many years, doctors have focused mainly on the top number because high systolic pressure is strongly tied to heart disease and stroke. But this study shows that the bottom number also plays an important role, especially in brain health.
To learn more, the researchers studied 1,205 adults aged 50 and older. They measured each person’s blood pressure and used MRI scans to look closely at their brains. They were searching for something called white matter lesions. These are tiny scars in the brain that affect how nerve signals move from one part of the brain to another.
Even though they are small, they can slow down or interrupt communication inside the brain. Over time, this can cause problems with memory, balance, and thinking clearly. White matter lesions also increase the risk of strokes, dementia, and falls.
The results of the study were striking. People with lower diastolic blood pressure, meaning below 80, had fewer white matter lesions. In contrast, people with higher diastolic pressure, above 90, had more of these brain scars. This suggests that keeping the lower blood pressure number in a healthy range may help protect the brain from damage as people age.
Previous research has shown that high systolic blood pressure can narrow arteries and reduce blood flow to the brain. That lack of blood flow can damage brain tissue over time.
However, this new study shows that diastolic pressure may affect different parts of the brain, especially areas involved in memory and thinking. This means that both numbers matter, and doctors should pay attention to the whole blood pressure reading, not just the top number.
White matter plays a major role in how the brain works. It contains bundles of nerve fibers that act like “information highways,” helping different parts of the brain communicate quickly and smoothly. When white matter becomes damaged, those pathways slow down or break. Imagine a busy road system with potholes or broken bridges.
Traffic slows, detours appear, and everything becomes harder to navigate. The same thing happens in the brain when white matter lesions form. This can lead to poor balance, confusion, forgetfulness, and difficulty focusing.
White matter lesions become more common with age. The American Heart Association reports that about 10 to 20 percent of people have them by age 60, and they appear in the majority of people over 90. Because these lesions are so strongly linked to dementia and stroke, learning how to prevent them is extremely important.
The new study, led by researcher Michelle R. Caunca, suggests that controlling diastolic blood pressure may be one way to protect the brain. It also highlights the need for doctors to watch both blood pressure numbers and not ignore the lower one.
The study also points out that different parts of the brain receive blood from different arteries. When blood pressure is too high, it may damage specific brain regions in different ways. Understanding these patterns could help doctors create better treatments to keep the brain healthy.
The message from the researchers is clear: everyone should know their blood pressure numbers and talk with their doctor about how to keep them in a healthy range. Managing blood pressure properly does not only protect the heart. It may also be one of the most important steps a person can take to protect their brain as they age.
If you care about high blood pressure, please read studies that early time-restricted eating could help improve blood pressure, and natural coconut sugar could help reduce blood pressure and artery stiffness.
For more health information, please see recent studies about added sugar in your diet linked to higher blood pressure, and results showing vitamin D could improve blood pressure in people with diabetes.
This research was published in the journal Stroke.
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