The constriction of cells surrounding blood vessels may cause decreased blood flow to the brain linked to Alzheimer’s disease. File Photo by Riff/Shutterstock

June 20 (UPI) -- Researchers may be closer to discovering a cause of cognitive decline brought on by Alzheimer's disease, a new study says.

The constriction of cells surrounding blood vessels may cause decreased blood flow to the brain, which has already been linked to Alzheimer's disease, according to research published Thursday in the journal Science.


"Since reduced blood flow is the first clinically detectable sign of Alzheimer's, our research generates new leads for possible treatments in the early phase of the disease," Ross Nortley, a researcher at University College London and study lead author, said in a news release.

The researchers analyzed capillaries in human brain tissue affected by Alzheimer's and in mice engineered to grow a pathology for the disease. They applied a protein that grows in the brains of Alzheimer's disease patients called amyloid beta to healthy tissues in the brain -- finding that capillaries were squeezed after the application.

"In clinical trials, drugs that clear amyloid beta from the brain have not succeeded in slowing mental decline at a relatively late phase of the disease," said David Attwell, a researcher at University College London and study senior author. "We now have a new avenue for therapies intervening at an earlier stage."

Since blood delivers glucose and oxygen to energize the brain, the researchers suggest this contributes to cognitive decline.

They found the constriction was tight enough to cut blood flow in half, resembling reduced blood flow in other regions of the brain affected by Alzheimer's.

"In clinical trials, drugs that clear amyloid beta from the brain have not succeeded in slowing mental decline at a relatively late phase of the disease," Attwell said. "We now have a new avenue for therapies intervening at an earlier stage."