New PNAS research shows that the symptoms of dementia are written in the blood

Studies have shown that compared with elderly people without any health conditions, the levels of 33 metabolites in patients with dementia are different

"Metabolites are chemicals produced by important chemical reactions occurring in cells and tissues," said first author Dr.

Dementia is not a single disease, but a general term used to describe a series of symptoms, including slow but usually irreversible declines in memory, thinking, decision-making, or daily activities

Although scientists know that dementia is caused by nerve damage, the exact cause of this damage and how to detect and treat this damage are still elusive

In this study, the research team analyzed blood samples from 8 dementia patients and 8 healthy elderly people

"Blood cells are difficult to process because if they are not treated, even for a short period of time, they will undergo metabolic changes," Dr.

However, the research team recently developed a method to stabilize the metabolites in red blood cells, allowing them to examine the relationship between red blood cell activity and dementia for the first time

Scientists measured the levels of 124 different metabolites in whole blood and found 33 metabolites, divided into 5 different subgroups, which are related to dementia

Professor Mitsuhiro Yanagida, senior author of the study and head of the OIST G0 cell unit, said: "Identifying these compounds means that we are one step closer to being able to diagnose dementia with molecules

The 7 metabolites that are elevated in dementia patients are found in the plasma and belong to the subgroup A of metabolites

Professor Yanagida said: "It is too early to say this, but this may indicate the possible mechanism of dementia, because these compounds may cause brain damage

The research team plans to test this idea in the next study, by observing whether the increase in these metabolites can induce dementia in animal models such as mice

Compared with healthy elderly people, the remaining 26 compounds reduced in dementia patients belong to the other 4 metabolite subgroups BE

The 6 metabolites that are reduced in patients with dementia are classified as category B due to their similar structures

"Red blood cells may not only provide oxygen, but also provide key metabolites that protect the nervous system from damage," said Dr.

Researchers believe that the remaining subgroups contain compounds that play a role in providing nutrients, maintaining energy reserves, and protecting neurons from damage

Professor Yanagida said: "In the future, we hope to start some intervention studies, either to supplement patients with dementia with the metabolic compounds of the BE subgroup, or inhibit the neurotoxins in the A subgroup, to see if this can slow down, prevent, or even reverse the symptoms of dementia
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This research was jointly conducted by the Okinawa Graduate School of Science and Technology, Okinawa Ryukyu National Hospital, and Kyoto University
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Journal Reference :

1. Takayuki Teruya, Yung-Ju Chen, Hiroshi Kondoh, Yasuhide Fukuji, and Mitsuhiro Yanagida.
   Whole-blood metabolomics of dementia patients reveal classes of disease-linked metabolites .
   PNAS , 2021 DOI: 10.
   1073/pnas.
   2022857118