According to the researchers from the University of British Columbia and Chinese scientists, Alzheimer’s disease could be triggered by breakdowns elsewhere in the body. Drug therapies might be able to stop or slow the disease without acting directly on the brain. However, drugs could target the kidney or liver, ridding the blood of a toxic protein before it ever reaches the brain. The findings are published in Molecular Psychiatry.

With the aid of a technique called parabiosis, researchers demonstrated the cancer-like mobility. The two specimens are surgically attached so that they share the same blood supply for several months.

Dr Weihong Song, UBC Psychiatry Professor and Yan-Jiang Wang, Neurology Professor at Third Military Medical University conducted the study.  In the study, they attached normal mice to genetically modified mice. The genetically modified mice were altered to produce high levels of amyloid-beta (the protein present in Alzheimer's disease).

On examination, the researchers found that the normal mice that were joined to the genetically modified mice for 12 months contracted Alzheimer’s disease. The amyloid-beta was transferred from the genetically- modified mice to the brains of the normal mice, accumulated and began to inflict damage.

The normal mice developed plaques as well as pathology similar to "tangles". Eventually, the mice died due to the disrupted function in their brain. Brain cell degeneration, microbleeds, inflammation, impairment of learning and memory were characteristics of Alzheimer disease.

Amyloid-beta is produced in blood platelets, muscles, blood vessels, and its precursor protein are found in several other organs. It was unclear whether amyloid-beta from outside the brain contributed to Alzheimer's disease. However, Song proved that amyloid-beta from outside also caused the disease in the present study.

"The blood-brain barrier weakens as we age." Thus, more amyloid beta could be infiltrated in the brain, besides that is produced by the brain itself and speeding up the deterioration.

A drug was found to bind amyloid-beta throughout the body and eliminate out through the liver or kidneys. Although Alzheimer's disease is the disease of the brain, the researchers have to consider the whole body to understand where it comes from, and how to stop it, Song added.

The study concluded that Alzheimer’s disease could be triggered by breakdowns from other parts of the body