Scientists at the University of California, Irvine, have made a surprising discovery that may change how we think about brain bleeding, especially in older adults.
Their research shows that aging red blood cells might be directly causing tiny brain bleeds, also known as cerebral microbleeds.
For a long time, experts believed that these small brain hemorrhages mainly happened because of damaged blood vessels. But this new study, led by Dr. Mark Fisher and Dr. Xiangmin Xu, shows a different cause—older red blood cells getting stuck in the brain’s tiniest blood vessels.
These small vessels, called capillaries, are essential for bringing oxygen and nutrients to the brain. But they are also delicate and can easily be damaged. To understand what happens with aging red blood cells, the researchers first made the cells undergo a process called oxidative stress. This simulates what naturally happens to red blood cells as people age.
Next, they labeled the stressed red blood cells with glowing markers and injected them into mice. What they saw was unexpected: the aged red blood cells got trapped in the brain’s capillaries. This triggered an immune response in the brain.
The brain has special immune cells called microglia. Normally, these cells clean up waste and protect the brain. But in this case, the microglia tried to remove the trapped red blood cells. That process caused inflammation and led to tiny bleeds in the brain.
This new understanding is important because cerebral microbleeds have been linked to serious conditions like high blood pressure, Alzheimer’s disease, and certain types of strokes. If aging red blood cells are a key cause, then future treatments could focus on preventing this buildup and the resulting inflammation.
Dr. Fisher explained that this discovery could lead to better ways of managing and possibly preventing brain hemorrhages as people get older. The research team plans to keep studying how the brain handles damaged red blood cells and whether this process plays a role in other stroke types.
This study could lead to new treatments that help protect the aging brain. By focusing on how old red blood cells behave, doctors may find ways to reduce the risk of brain damage in older adults.
For those concerned about brain health, this research adds another piece to the puzzle. It also supports other studies showing how lifestyle factors like a healthy diet can protect the brain. For example, the Mediterranean diet and foods like wild blueberries have been shown to support both brain and heart health.
If you care about stroke, please read studies that diets high in flavonoids could help reduce stroke risk, and MIND diet could slow down cognitive decline after stroke.
For more health information, please see recent studies about antioxidants that could help reduce the risk of dementia, and tea and coffee may help lower your risk of stroke, dementia.
The full study can be found in the Journal of Neuroinflammation.
Copyright © 2025 Knowridge Science Report. All rights reserved.
