Cerebral blood flow is associated with plasma and PET biomarkers of tau pathology in middle age.

Summary: Alzheimer's disease might start damaging the brain long before memory loss actually begins. Researchers wanted to know if poor blood flow in the brain is connected to this early damage. They looked at a group of middle-aged adults, around 55 years old, to see how their brain blood flow relates to a harmful protein called "tau," which is known to cause Alzheimer's.

Using brain scans and blood tests, the scientists discovered a clear link: people with lower blood flow in their brains had higher levels of the harmful tau protein. This connection was found both in their blood and in specific areas of the brain where Alzheimer's usually starts. The researchers believe that poor blood flow and the buildup of tau proteins likely make each other worse. Finding this connection early in midlife could help doctors figure out new ways to prevent Alzheimer's before it causes serious memory problems.