A new Australian study suggests that sudden changes in blood pressure may increase the risk of dementia and other serious blood vessel problems in older adults.
The findings add to growing evidence that brain health is closely connected to the health of the heart and blood vessels.
For many years, doctors have known that high blood pressure, also called hypertension, is a major risk factor for dementia, stroke, and heart disease. However, the new research suggests that another factor may also be important: how much blood pressure changes throughout the day and over time.
The study was led by researchers from the University of South Australia and published in the journal Cerebral Circulation – Cognition and Behaviour.
The scientists found that older adults whose blood pressure fluctuated more often showed weaker thinking and memory abilities and signs of stiffer arteries, even though they did not yet have dementia.
Researchers say the findings may help doctors identify people at higher risk much earlier, before serious symptoms begin.
The study focused on something called blood pressure variability. Blood pressure naturally changes during the day depending on activity, stress, sleep, exercise, emotions, and other factors. However, some people experience larger swings than others.
Doctors usually focus mainly on whether blood pressure is too high or too low. But according to the researchers, large ups and downs in blood pressure may place extra stress on blood vessels and reduce stable blood flow to important organs like the brain.
Daria Gutteridge, a PhD student from UniSA’s Cognitive Ageing and Impairment Neuroscience Laboratory, explained that blood pressure variability is often overlooked in routine healthcare.
She said many treatments for hypertension are designed to lower blood pressure overall, but they may not fully address frequent fluctuations. According to Gutteridge, these swings may make blood vessels and brain tissue more vulnerable to damage over time.
To investigate the issue, the researchers studied 70 healthy adults between the ages of 60 and 80. None of the participants had dementia or noticeable memory problems when the study began.
Over time, the team carefully monitored participants’ blood pressure patterns. The volunteers also completed cognitive tests designed to measure thinking ability, memory, and mental performance. In addition, researchers examined the stiffness of the participants’ arteries.
The results showed a clear connection. People whose blood pressure varied more strongly tended to perform worse on cognitive tests. They also had stiffer arteries, especially when the systolic blood pressure showed large fluctuations.
Systolic blood pressure is the top number in a blood pressure reading. It measures the pressure inside arteries when the heart pumps blood out to the body. Researchers found that swings in this number appeared particularly linked to blood vessel stiffening and reduced cognitive performance.
Stiff arteries are a serious health concern because they can interfere with healthy blood flow. Normally, arteries are flexible and help maintain smooth circulation. But when arteries become stiff, blood flow to organs like the brain may become less stable and less efficient.
The brain needs a constant and reliable supply of oxygen and nutrients carried by the blood. If blood flow becomes unstable over time, brain cells may not function as well, which could gradually affect memory, concentration, and thinking abilities.
Researchers believe this may help explain why blood pressure variability could contribute to dementia risk.
One important finding from the study is that these changes were detected in people who still appeared healthy and had no dementia symptoms. This suggests that blood pressure fluctuations could act as a very early warning sign long before noticeable memory decline begins.
The researchers say this may open new opportunities for prevention. If doctors can identify people with unstable blood pressure patterns earlier, they may be able to recommend treatments or lifestyle changes before major brain damage occurs.
The study also highlights the growing understanding that dementia is not caused by only one factor. Instead, experts now believe dementia often develops through a combination of aging, blood vessel health, inflammation, genetics, and lifestyle factors such as diet, exercise, smoking, sleep, and stress.
Because blood pressure monitors are simple and widely available, researchers say monitoring blood pressure variability could become a practical way to assess future brain health risk.
The researchers hope the findings encourage doctors to pay closer attention not just to average blood pressure levels, but also to how much blood pressure changes from day to day or even hour to hour.
Although the study was relatively small, involving only 70 participants, experts say the findings are important because they support growing evidence linking vascular health to dementia risk.
Future research will be needed to confirm whether reducing blood pressure variability can directly lower the risk of dementia and cognitive decline. Scientists also want to better understand what causes some people to experience greater blood pressure swings than others.
In the meantime, the study serves as another reminder that protecting heart and blood vessel health may also help protect the brain.
Researchers believe that maintaining stable blood pressure through healthy lifestyle habits, regular medical care, exercise, stress management, and proper treatment may play an important role in healthy aging.
Copyright © 2026 Knowridge Science Report. All rights reserved.
