Blood Test Could Detect Parkinson’s Disease Decades Before Symptoms Appear, New Study Finds

Researchers in Sweden and Norway have made a breakthrough discovery that could potentially revolutionize early detection of Parkinson’s disease through simple blood tests, identifying biomarkers up to 20 years before visible symptoms develop.

Scientists from Chalmers University of Technology in Sweden and Oslo University Hospital in Norway found that in the very early stages of Parkinson’s, the body undergoes changes related to DNA repair and cellular stress responses. These changes leave detectable markers in the blood long before significant brain damage occurs.

“We’ve found an important window of opportunity,” explained Annikka Polster, assistant professor at the Department of Life Sciences at Chalmers and the study’s lead researcher. “The disease can be detected before motor symptoms caused by nerve damage in the brain appear.”

This early detection window is particularly significant because by the time traditional Parkinson’s symptoms become apparent, extensive neurological damage has already occurred. Danish Anwer, a doctoral student at Chalmers and the study’s first author, noted: “By the time the motor symptoms of Parkinson’s disease appear, 50% to 80% of the relevant brain cells are often already damaged or gone.”

The research team used advanced machine learning techniques to identify specific patterns linked to DNA repair processes and cellular stress. Crucially, these patterns were not found in healthy individuals or in patients already diagnosed with Parkinson’s, indicating they are unique to the disease’s early development phase.

Parkinson’s disease affects more than 10 million people worldwide, with approximately 90,000 new diagnoses annually in the United States alone. As the second most common neurodegenerative disorder after Alzheimer’s disease, these numbers are expected to rise in coming years, highlighting the urgent need for better diagnostic and treatment approaches.

Currently, diagnosis typically occurs only after visible symptoms emerge, which can include tremors, slowed movement, muscle stiffness, and difficulties with balance and walking. Non-motor symptoms may include loss of smell, sleep disorders, constipation, fatigue, depression, anxiety, and cognitive changes.

Dr. Marc Siegel, a medical analyst not involved in the study, called the research “exciting,” suggesting it “opens the door for earlier and more effective diagnosis and treatment.” He emphasized how devastating the disease progression can be, noting that “by the time you have actual motor symptoms affecting gait, tremor, etc., a large majority of affected cells have been damaged and destroyed.”

The researchers are optimistic about the potential impact of their discovery, predicting that blood tests for early Parkinson’s diagnosis could become common in clinical practice within five years. Their findings, published in the journal npj Parkinson’s Disease, also open new avenues for therapeutic development.

“If we can study the mechanisms as they happen, it could provide important keys to understanding how they can be stopped and which drugs might be effective,” Polster explained. “This may involve new drugs, but also drug re-purposing, where we can use medications developed for other diseases because the same gene activities or mechanisms are active.”

The team acknowledged several limitations to their research. The gene activity measured in blood only partially matches what happens in the brain, and external factors like medication use might have influenced the results. Additionally, the study population may not represent all demographic groups, potentially limiting the broad applicability of the findings.

Despite these limitations, the discovery represents a significant step forward in the battle against a disease that currently has no cure, only treatments to manage symptoms. The ability to detect Parkinson’s decades before symptoms appear could dramatically change treatment approaches, potentially allowing intervention when the disease might be slowed or even prevented.

The researchers plan to further develop tools to more easily detect these active mechanisms and better understand how they work, bringing hope to millions affected by this progressive neurological disorder.