Scientists in Canada have discovered that Alzheimer’s disease could be linked to a surplus of blood vessels in the brain. Researchers at the University of British Columbia studied brain tissue from mice bred to mimic Alzheimer’s, and found they had nearly double the number of capillaries compared to normal mice.
The team then looked at brain samples from people who had died with Alzheimer’s, and found that they also had more capillaries than samples taken from healthy people. The researchers believe that in people with Alzheimer’s, blood vessel growth may be stimulated by the toxic protein called amyloid – one of the hallmarks of the disease. They suggest that as the blood vessels grow, the blood-brain barrier could be made temporarily weaker, allowing amyloid to reach the brain where it builds and destroys brain cells. Commenting on this news, Dr Marie Janson, director of development at Alzheimer’s Research UK, said: “It is not yet clear whether increases in blood vessels are to blame for Alzheimer’s, but it will be interesting to see if drugs that tackle vessel growth could act as a treatment. Meanwhile, in the US, researchers have found that brain scans could help identify the early signs of Alzheimer’s disease before symptoms begin to show. Researchers at the Mayo Clinic, in Minnesota, studied 311 cognitively healthy people in their 70s and 80s. They carried out a series of tests to assess their memory, thinking and language skills, as well as two sets of brain scans. PET scans were used to track levels of amyloid. A second brain imaging technique, called proton magnetic resonance spectroscopy (H-MRS), was used to measure several brain metabolites. They found that people with high levels of amyloid in their brains tended to have high levels of some brain metabolites. People with a high ratio of certain metabolites, choline/ creatine, also scored lower in cognitive tests, whether or not they had high levels of amyloid. The researchers believe H-MRS imaging could be used to identify people at risk of developing Alzheimer’s disease before symptoms appear, and want to see follow-up studies to test this theory.
