Parkinson’s disease is one of the fastest-growing neurological conditions in the world, yet it is usually diagnosed far too late.
By the time most people receive a diagnosis, a large number of brain cells responsible for movement control have already been damaged or lost.
A new study led by researchers at Chalmers University of Technology in Sweden now suggests that the earliest signs of Parkinson’s disease may briefly appear in the blood, long before major damage occurs in the brain. This discovery could open the door to earlier diagnosis and even preventive treatment in the future.
Parkinson’s disease affects more than 10 million people worldwide and is considered an endemic condition, meaning it is widespread and persistent across populations. As societies age, the number of people living with Parkinson’s is expected to more than double by 2050.
Despite this growing burden, there is currently no cure and no routine screening test that can detect the disease before movement problems begin. This makes early intervention extremely difficult.
The new findings were published in the journal npj Parkinson’s Disease by a research team from Chalmers University of Technology and Oslo University Hospital in Norway. The study focuses on the very earliest phase of Parkinson’s disease, often called the prodromal stage.
During this long and quiet phase, which can last up to 20 years, subtle changes are already happening inside cells, even though outward symptoms are mild or completely absent.
The researchers looked closely at two key biological processes that are thought to play a role early in the disease. The first is DNA damage repair, which is the system cells use to detect and fix damage to their genetic material.
The second is the cellular stress response, a protective reaction that helps cells survive difficult conditions by shifting energy away from normal tasks and toward repair and defense. Both processes are essential for keeping cells healthy, especially in the brain.
Using advanced data analysis and machine learning techniques, the team examined patterns of gene activity linked to these processes. They discovered a unique signature that appeared only in people at the very early stage of Parkinson’s disease.
This pattern was not seen in healthy individuals, and it also disappeared in patients who had already developed clear movement symptoms. This suggests that the biological signal exists only for a limited window of time.
According to the researchers, this short-lived signal represents a critical opportunity. Once the typical motor symptoms of Parkinson’s disease appear, such as tremors, stiffness, and slowed movement, between 50 and 80 percent of the relevant brain cells are often already damaged or gone.
Detecting the disease before this point could allow doctors to intervene while the brain is still largely intact.
One of the most important aspects of the study is that these early biological changes can be detected in blood samples.
Many previous attempts to identify early Parkinson’s markers have relied on brain imaging or spinal fluid tests, which are expensive, invasive, and impractical for large-scale screening. Blood tests, by contrast, are simple, affordable, and widely accessible.
The researchers believe this work could lead to the development of blood-based screening tests that identify people at risk before symptoms appear. They estimate that within five years, such tests could begin to be trialed in healthcare settings. This timeline reflects the need for further validation, refinement, and testing in diverse populations.
Beyond diagnosis, the findings may also guide future treatment development. By studying the disease while these early biological mechanisms are active, scientists may gain valuable insight into how Parkinson’s begins and progresses.
This knowledge could help identify drugs that slow or stop the disease process. In some cases, it may even be possible to reuse existing medications developed for other conditions if they target the same cellular pathways.
Parkinson’s disease itself develops slowly and often starts with non-motor symptoms that are easy to overlook. These can include acting out dreams during sleep, a reduced sense of smell, constipation, depression, and anxiety.
Motor symptoms usually appear much later and include tremors, muscle stiffness, slow movement, and balance problems. Because early symptoms are subtle and non-specific, many people are diagnosed only after the disease has caused significant harm.
In reviewing the study’s findings, the message is both hopeful and urgent. The research shows that Parkinson’s disease leaves detectable traces long before classic symptoms appear, but that these signals may fade as the disease advances. This means timing is critical. If early detection tools are not developed and used, this opportunity may be missed.
While more research is needed before blood tests become part of routine care, the study represents a major step toward shifting Parkinson’s diagnosis from late-stage recognition to early prevention. If successful, this approach could change how the disease is managed, reduce long-term disability, and improve quality of life for millions of people worldwide.
If you care about Parkinson’s disease, please read studies that Vitamin B may slow down cognitive decline, and Mediterranean diet could help lower risk of Parkinson’s.
For more information about brain health, please see recent studies that blueberry supplements may prevent cognitive decline, and results showing Plant-based diets could protect cognitive health from air pollution.
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