Researchers in Japan say they have developed a simple technique to detect Alzheimer's disease before symptoms appear.
The National Center for Geriatrics and Gerontology, or NCGG, and precision machinery firm Shimadzu Corporation carried out the joint project.
Alzheimer's is a cause of dementia. A substance called beta-amyloid is known to start accumulating in patients' brains more than 20 years before symptoms develop. But it requires expensive testing to diagnose the disease at an early stage.
The researchers say the new technique is based on their discovery that the amount of beta-amyloid in blood decreases when the substance builds up in the brain.
They say they were able to detect a beta-amyloid build-up with about a 90 percent accuracy rate in a clinical study involving about 230 elderly people in Japan and Australia.
Koichi Tanaka, who won the Nobel Prize for Chemistry 16 years ago, is a member of the Shimadzu side of the project.
He said he will continue working so that the technique for measuring a tiny amount of substances can be applied to treatment and examination of diseases.
NCGG Research Institute Director Katsuhiko Yanagisawa said the new method will be used for research purposes for the time being. But he added he hopes it will have a role in health checkups in the future.