Most people know that high blood pressure can increase the risk of heart attacks and strokes.
When doctors talk about blood pressure, they often pay close attention to the top number, known as systolic blood pressure.
However, new research suggests that the lower number in a blood pressure reading may also play an important role, especially when it comes to protecting the brain as people grow older.
Scientists from the University of Miami have discovered evidence that diastolic blood pressure, the lower number in a blood pressure reading, may help predict the risk of developing damage inside the brain that is linked to dementia, memory problems, strokes, and even falls.
Their findings add to growing evidence that both blood pressure numbers are important and that focusing only on the top number may overlook valuable information about brain health.
Blood pressure readings contain two numbers. The top number, called systolic pressure, measures the force of blood pushing against artery walls when the heart beats. The lower number, called diastolic pressure, measures the pressure in the arteries when the heart relaxes between beats.
For many years, doctors have paid more attention to systolic pressure because it is strongly linked to cardiovascular disease. However, researchers are now learning that diastolic pressure may also have a significant effect on the brain.
To better understand this connection, the research team studied 1,205 adults who were at least 50 years old. The participants had their blood pressure measured and also underwent magnetic resonance imaging, commonly known as MRI scans.
These detailed brain scans allowed scientists to look for white matter lesions, which are small areas of damage or scarring in the brain.
White matter is a vital part of the brain. It contains millions of nerve fibers that connect different brain regions and allow them to communicate with one another. These connections help people think, remember, move, and maintain balance.
White matter can be compared to a network of highways that carries information throughout the brain. When damage develops along these pathways, communication becomes slower and less efficient.
White matter lesions may be tiny, but they can have serious effects over time. They are linked to problems with memory, concentration, balance, and clear thinking. Research has also connected them to an increased risk of stroke, dementia, and falls in older adults.
As people age, these lesions become more common. According to the American Heart Association, about 10% to 20% of people have white matter lesions by the age of 60, and they are found in most people over the age of 90.
The researchers found a clear pattern. People whose diastolic blood pressure was below 80 tended to have fewer white matter lesions. In contrast, those whose diastolic pressure was above 90 showed more signs of brain damage.
This finding suggests that maintaining a healthy diastolic blood pressure may help reduce damage to the brain and support healthy aging.
Previous studies have already shown that high systolic blood pressure can damage blood vessels, narrow arteries, and reduce blood flow to the brain. Over many years, this reduced blood supply can harm brain tissue.
The new study suggests that diastolic pressure may affect the brain in different ways and may be especially important for areas involved in memory and thinking.
The researchers also noted that different parts of the brain receive blood from different arteries. High blood pressure may affect these blood vessels differently depending on their location.
As a result, certain brain regions may be more vulnerable to damage. Understanding these patterns could help scientists develop better ways to prevent brain disease and protect mental function in older adults.
The study was led by researcher Michelle R. Caunca and provides another reminder that blood pressure affects much more than the heart. Healthy blood vessels are essential for delivering oxygen and nutrients to brain cells. When blood pressure remains too high for long periods, the risk of damage increases.
The findings may encourage doctors to pay closer attention to both numbers in a blood pressure reading rather than focusing mainly on systolic pressure. They also highlight the importance of regular blood pressure checks, especially for middle-aged and older adults.
Keeping blood pressure in a healthy range often involves a combination of healthy habits, such as regular physical activity, a balanced diet, maintaining a healthy weight, limiting excess salt, avoiding smoking, and following medical advice when treatment is needed.
These steps are commonly recommended for heart health, but they may also help protect the brain.
The researchers believe that learning more about how blood pressure affects different parts of the brain could lead to improved prevention strategies in the future. As the global population ages and the number of people living with dementia continues to rise, understanding the factors that contribute to brain damage becomes increasingly important.
The study was published in the journal Stroke. Its findings suggest that the lower number in a blood pressure reading may provide valuable clues about future brain health. The message is simple: knowing and managing both blood pressure numbers may help people not only protect their hearts but also maintain healthier brains 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 information about blood pressure, please see recent studies about How to eat your way to healthy blood pressure and results showing that Modified traditional Chinese cuisine can lower blood pressure.
Copyright © 2026 Knowridge Science Report. All rights reserved.
