Research has demonstrated that fluctuating blood pressure can be a harbinger for both dementia and heart disease. Ups and downs within 24 hours or even over several days or weeks were linked with impaired thinking, scientists from Australia reported.

Higher variations in systolic blood pressure, the top number, were linked with stiffening of the arteries, which is associated with heart disease.

Researchers studied this in 70 healthy older adults ages 60 to 80 who had no signs of dementia or thinking impairment. The team monitored participants’ blood pressure, gave them a cognitive test, and measured arterial stiffness in their brains and arteries.

“We found that higher blood pressure variability within a day, as well as across days, was linked with reduced cognitive performance. We also found that higher blood pressure variations of the systolic BP [blood pressure] were linked with higher blood vessel stiffness in the arteries,” said lead author Daria Gutteridge, a Ph.D. candidate at the University of South Australia’s Cognitive Ageing and Impairment Neuroscience Laboratory.

“These results indicate that the different types of BP variability likely reflect different underlying biological mechanisms, and that systolic and diastolic blood pressure variation are both important for cognitive functioning in older adults.”