The disease

Alzheimer's is the leading cause of dementia worldwide. The incurable disease slowly impairs cognitive function, such as the ability to think and remember. Because of these devastating effects on the brain, it has long been assumed that Alzheimer's originates in the brain. But new research has found that Alzheimer's might be a disease that originates in other parts of the body and travels to the brain.

The breakthrough

Amyloid-beta is a protein linked to Alzheimer's disease. It is present in all healthy people, but when it builds up or becomes over-produced in the brain, it becomes toxic and starts to inflict the type of damage associated with Alzheimer's. But amyloid-beta is found throughout the body, not just the brain. It exists in many other body parts including the liver and kidneys, spinal fluid and muscles. In the experiment, Dr. Weihong Song, a Professor of Psychiatry and Canada Research Chair in Alzheimer's at the University of British Columbia, fused two mice together so that they shared the same blood supply for several months. One mouse was completely normal; the other was modified to carry a mutant human gene that produces high levels of amyloid-beta. After a period of time, the amyloid-beta from the modified mouse had travelled to the brain of the normal mouse, where it began to create damage. The experiment demonstrated the ability of amyloid-beta to travel, similar to cancer, from one part of the body to the brain.

The future

In the future, the treatment of Alzheimer's disease may begin in other parts of the body, apart from the brain. A build up of amyloid-beta in the liver or kidneys for example may be easier to treat than a similar accumulation in the brain. Now that it is known that amyloid-beta can travel throught the blood-brain barrier like this, Alheimer's drugs of the future may also target other places in the body.