Scientists in Sweden and Norway have identified a set of blood-based biomarkers that could allow Parkinson’s disease to be detected years – potentially decades – before the onset of movement-related symptoms.
This marks a significant breakthrough in early diagnosis of the neurodegenerative condition.
The research, led by Chalmers University of Technology in Sweden in collaboration with Oslo University Hospital, was published in January 2026 in the journal npj Parkinson’s Disease.
Parkinson’s disease currently affects more than 10 million people worldwide, a figure expected to more than double by 2050 as populations age.
Parkinson’s is diagnosed primarily through clinical examination after motor symptoms such as tremor, stiffness, and slowed movement emerge. By that stage, 50% to 80% of dopamine-producing brain cells may already be severely damaged or lost, limiting the effectiveness of treatment.
The new study focuses on the very early, or “prodromal”, phase of Parkinson’s disease, which can last up to 20 years before motor symptoms become visible.
During this period, subtle changes occur inside cells, particularly in DNA damage repair mechanisms and the cellular stress response, both of which help cells survive and maintain genetic integrity.
Using machine-learning techniques, researchers analysed gene activity patterns in blood samples and identified a distinct molecular signature linked to these two processes.
This signature was present only in individuals believed to be in the earliest stages of Parkinson’s and was absent in both healthy participants and patients with established disease.
According to the researchers, the fact that these biomarkers appear only briefly makes them especially valuable for diagnosis.
The findings point to a narrow but crucial window during which Parkinson’s disease leaves a measurable trace in the blood, before extensive brain damage occurs.