Japanese and Australian researchers have developed a simple and affordable blood test to diagnose Alzheimer's disease, they reported in the science journal Nature on Wednesday.

The new method to check the buildup of a protein in the brain, which is believed to be linked to the disease, will potentially enable "broader clinical access and efficient population screening," said the team that includes Nobel chemistry laureate Koichi Tanaka of Shimadzu Corp.

While the cause of Alzheimer's, the most common form of dementia, is not exactly known, abnormal buildup of the protein amyloid-beta is said to be one of the factors that lead to its development.