The investigators hypothesise that measuring biomarkers of oxidative damage could better inform investigators on the potential merits (and pitfalls) of CoQ10 supplementation in PD subjects.

Subjects with idiopathic PD will be recruited to a 10-week dose escalation study. Each dosage (400mg/day, 800mg/day, 1200/day and 2400mg/day) will be consumed daily for two weeks. Information on safety and fasting blood/urine samples will be collected. Primary endpoint is plasma F2-isoprostanes (adjusted for arachidonate) while secondary endpoint is the change in the total Unified Parkinson Disease Rating Scale (UPDRS) before and after treatment. Serum phospholipase A2 activities, plasma all trans-retinol, plasma total tocopherol (sum of α-, δ- and γ-tocopherol) and serum uric acid will be measured.

Inclusion Criteria:

• idiopathic Parkinson disease
• age >21 years
• able to provide written informed consent

Exclusion Criteria:

• diabetes mellitus, stroke, cardiac and renal diseases and cigarette smoking
• major psychiatric disorder or drug and/or alcohol abuse/dependence
• regular use of antioxidants, dietary supplements, traditional Chinese remedies, non-steroidal anti-inflammatory drugs or immunosuppressive drugs