A barrier of blood capillaries in the brain that becomes permeable with age facilitates the onset of Alzheimer's disease, according to a study conducted in California that highlights the importance of discovery for disease prevention.
The research, published today, highlighted the importance of strengthening these capillary vessels to prevent the passage of harmful, pathogenic and other toxic substances to the brain, which in turn may delay or contain the progression of Alzheimer's.
The study was conducted by the Keck School of Medicine of the University of Southern California (USC), which followed 161 older adults for five years.
"We are finding that the blood capillaries of the brain show permeability when people have medium-level cognitive deficits," said one of the study's authors, Berislav Zlokovic, director of the Zilkha Neurogenetic Institute at USC Keck.
He noted that filtrations in this brain barrier "occur independently of changes in (proteins) tau and amyloid", characteristic of Alzheimer's disease.
The study showed that people with multiple memory problems also have the highest amount of loss in their brain blood tissues, regardless of whether they both show abnormal conditions.
In healthy brain tissues, the cells that form the blood vessels cluster so tightly that they form a barrier that prevents the passage of loose cells, pathogens, metals and other substances harmful to the brain, the report states.
In contrast, "in some aging brains, this firmness is lost creating permeability in these tissues" which facilitates the passage of harmful cells to the brain.
"If the barrier of cerebral blood vessels does not work properly, there is the possibility of damage," added Arthur Toga, co-author of the report and director of the Stevens Institute of Informatics and Neuroimaging at USC Keck.
Daniel Nation, an assistant professor of psychology at the USC School of Arts and Science Dornsife and lead author of the research, said the discovery shows "another independent factor" in the cognitive problems of the elderly.
However, the study warns that a broader analysis is needed to better understand the damage of these brain losses and the most appropriate way to prevent them.