A recent study from the University of Southern California reveals that fluctuations in blood pressure may significantly impact brain health in older adults. Researchers discovered that the variability in blood pressure between heartbeats is linked to cognitive decline, particularly in regions of the brain associated with memory.
The findings indicate that older adults experiencing greater beat-to-beat changes in blood pressure had smaller brain volumes in memory-related areas. This correlation raises concerns about the effects of such fluctuations, even when overall blood pressure readings appear normal. According to Daniel Nation, a professor at USC and senior author of the study, “Even when blood pressure is well-controlled with medication, the rapid fluctuation in blood pressure from heartbeat to heartbeat is associated with worse memory and signs of brain shrinkage and brain cell injury.”
Research Methodology and Findings
The study involved 105 adults aged between 55 and 89. Researchers measured participants’ blood pressure continuously for several minutes while conducting brain scans. They specifically assessed arterial stiffness and variations in blood pressure between heartbeats. The results showed that individuals with erratic blood pressure readings and stiffer arteries exhibited significant signs of brain aging, despite having average blood pressure within healthy ranges.
Notably, the research identified smaller volumes in the hippocampus and entorhinal cortex, two brain regions that are often affected in the early stages of Alzheimer’s disease. Participants with greater blood pressure variability also had elevated levels of neurofilament light, a biomarker indicative of nerve-cell damage. These findings were significant even after adjusting for age, sex, and average blood pressure, suggesting that the fluctuations themselves may represent a key risk factor for cognitive decline.
Published online in the Journal of Alzheimer’s Disease on October 17, 2023, the study shifts the focus from high blood pressure alone to the instability of blood pressure as a potential contributor to the risk of dementia.
Implications and Future Research
The implications of this research are profound. While it has long been established that high blood pressure increases the risk of dementia, this study highlights how even those with “normal” readings may experience detrimental fluctuations that could affect brain health. Nation emphasized that these rapid variations in blood pressure were linked to brain injury, regardless of whether individuals had hypertension or were receiving treatment with blood pressure-lowering medications.
Nation noted, “Someone could have good readings at the doctor’s office and still have dangerous spikes and dips that quietly stress the brain’s delicate blood vessels.” Over time, this instability could lead to memory decline and neurodegeneration.
The researchers caution that their findings demonstrate correlation rather than causation, indicating a need for further studies to explore how these rapid fluctuations evolve over time and whether they predict future brain changes and cognitive decline. Nation stated, “Future studies should examine how these rapid blood pressure fluctuations change over time and whether they predict future brain shrinkage, brain cell injury, and memory decline.”
Currently, there are no specific treatments for managing blood pressure fluctuations. Nation urges individuals to monitor their blood pressure and adhere to prescribed medications to mitigate the risk of brain injury and cognitive decline. He also advocates for the development of therapies targeting rapid blood pressure fluctuations, suggesting that existing treatments focusing solely on lowering average blood pressure may not adequately address this issue.
As research continues to explore the intricate relationship between cardiovascular health and cognitive function, these findings underscore the importance of a holistic approach to health, particularly for aging populations.
