A group of Japanese experts announced Tuesday they have developed a blood test measure to detect signs of Alzheimer’s disease before patients show symptoms.

The discovery by a team led by Koichi Tanaka, a Nobel laureate in chemistry and a senior fellow of Kyoto-based Shimazu Corp., and the Aichi-based National Center for Geriatrics and Gerontology, was announced in a journal published by the Japan Academy.

One of the causes of Alzheimer’s disease is abnormal accumulation of the protein amyloid beta inside the brain. With the newly developed test, the team will examine how the protein builds up and how it harms a person’s cognitive functions, as there are some people who accumulate the protein but do not suffer from the disease.

“The accumulation of amyloid beta is the start of Alzheimer’s disease. So we’d like to develop medicines or treatment to deal with it,” said Katsuhiko Yanagisawa, vice director of the center.

The team is monitoring the brain conditions of 62 male and female examinees aged 65 to 85 by using positron emission tomography (PET). They analyzed their blood after confirming that their amyloid beta had accumulated.

Using a device for quality and quantity analysis developed by Tanaka and other experts, the team can detect small amounts of a protein related to amyloid beta that had never been detected before.

They are able to judge with high accuracy whether amyloid beta is accumulating by checking the ratio of this related protein as well as another type of related protein.

In the past, the only way to check if amyloid beta had built up was via PET, which is costly, or an examination of cerebrospinal fluid taken from a patient’s spinal cord.

“The amount of blood necessary for a test is just 0.5 cc. We’d like to make it one of the options attached to regular health checks in the future,” Tanaka said.