A widely prescribed liver medication awakens first cautious enthusiasm among researchers, as it shows the potential to slow the progression of Parkinson’s disease.
What is UDCA and how does it work in the body?
UDCA or ursodeoxycholic acid is a bile acid that is naturally produced in the liver. It helps to excrete other toxic bile acids and thus protects liver cells. UDCA is also produced synthetically and is used to treat gallstones and liver diseases.
In 2013, a research team led by Professor Oliver Bandmann, a neurologist for movement disorders at the University of Sheffield (UK), identified UDCA as a substance that could restore mitochondrial function in cells of Parkinson patients.
Why does mitochondrial function play a role in Parkinson?
Mitochondria are the “power plants” of cells and produce energy. Without energy, cells die. In certain genetic forms of Parkinson’s disease, mitochondria do not function properly, leading to cellular stress and neurodegenerative processes.
Dopaminergic neurons in the substantia nigra pars compacta (SNc), the area of the brain affected by Parkinson, have a special structure: Their large, heavily branched extensions (axons) form neural networks and transmit information. This process – called axonal arborization – requires a lot of energy and makes these neurons particularly dependent on functioning mitochondria.
UDCA and Parkinson: Early signs from the laboratory
Professor Bandmann found that UDCA normalized the energy production in skin cells of Parkinson patients with mutations in the genes PARK2 and LRRK2. Other researchers discovered that UDCA has anti-inflammatory and antioxidant properties, which have a neuroprotective effect. These effects have been confirmed in studies on flies and rodent models of Parkinson’s disease, which led Bandmann to test UDCA in humans.
Clinical study results: Can UDCA improve Parkinson symptoms?
The UP Study is a clinical study investigating the safety, tolerability, and potential of UDCA to slow Parkinson’s symptoms. In the first phase of the study (Phase 2), 30 Parkinson patients aged 50 to 70 received high doses of UDCA (in capsule form) for over a year. The treatment started with 250 mg (one capsule) daily and was gradually increased to 30 mg/kg body weight (9–10 capsules daily) since UDCA only reaches the central nervous system at this concentration.
Throughout the treatment, motor and non-motor symptoms, gait, side effects, etc. were assessed (see figure below). In addition, researchers analyzed the effect of UDCA on the brain chemistry of the participants using special magnetic resonance imaging (MRI).
The most important results of the UP Study:
- Improved gait: Participants receiving UDCA had better walking speed (+1.5 steps/minute) compared to untreated individuals, whose gait deteriorated (-4.5 steps/minute).
- Higher brain energy: Imaging showed improved energy production in cells, indicating enhanced mitochondrial function through UDCA.
- Good tolerance: The most common side effects were nausea and diarrhea, which subsided within 72 hours. Blood tests during all visits were unremarkable.
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- Disease-modifying potential: UDCA targets pathological mechanisms like mitochondrial dysfunction – unlike dopamine therapies, which only alleviate symptoms.
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- Low side effects and no severe adverse events.
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- Long-term use in liver diseases confirms safety for humans.
It’s important to note that people over 75 years were not included in the study. Also, the UDCA treatment group consisted of 70% men with a short disease duration (< 2 years). This limited sample size underscores the need for larger studies with more women and patients with longer disease history.
How does UDCA compare to other Parkinson therapies?
While early, UDCA offers hope for a treatment that goes beyond symptom relief. Its ability to improve mitochondrial function and potentially slow the progression of Parkinson’s disease makes it a promising candidate for future therapies. Should larger clinical studies confirm these findings, UDCA could become a safe and accessible option to protect brain health in Parkinson patients.