Investigating the Effect of Ginger Supplementation on Antioxidant and oxidant Markers, Clinical Outcome and Quality of Life in Patients with Parkinson's Disease: Double-blind, parallel, randomized controlled trial

This study aims to compare demographic, clinical and nutritional characteristics of patients with Parkinson’s disease and to evaluate the effects of ginger supplementation on Antioxidant and oxidant Markers, Clinical Outcome, quality of life and body mass index compared with placebo.

This is a randomized, double blind, parallel, placebo controlled clinical trial using stratified balanced block randomization.

A total of 48 patients will be recruited from the Isfahan Parkinson Charity Association. After a two week run in period, the intervention group will receive 1000 milligrams of ginger powder daily and the control group will receive placebo for 12 weeks.

Patients aged 50 to 80 years with Parkinson’s disease, body mass index above 18.5 and stable medication will be included. Exclusion criteria include special diets, recent ginger or antioxidant supplement intake, thyroid disorders, severe psychiatric or cognitive disorders, smoking, alcohol use, anticoagulant, anti inflammatory, immunosuppressive drugs or insulin use.

Participants will be randomly allocated to ginger or placebo groups.

Serum levels of Superoxide dismutase, Glutathione peroxidase, total antioxidant capacity, total oxidant status, Parkinson’s disease severity using the Movement Disorder Society Unified Parkinson’s Disease Rating Scale and Hoehn and Yahr scale, quality of life, body mass index, energy and nutrient intake and physical activity will be assessed.

Randomization will be performed using stratified block randomization with balanced blocks of size 4 and an allocation ratio of 1:1. The randomization process will be stratified based on sex and disease severity according to the Hoehn and Yahr scale. The random allocation sequence will be generated by the study statistician using the Sealed Envelope online randomization system. The sequence will then be stored in a password‑protected file inaccessible to the research team. Only the clinical officer of the Parkinson Charity Association, who is not involved in assessments or data collection, will have access to the sequence. Based on this sequence, ginger supplement bottles and placebo bottles will be prepared to be visually identical and labeled with sequential numeric codes. The bottles will be placed inside opaque, sealed, and tamper‑proof envelopes. Each participant will receive the envelope corresponding to their assigned code only after confirming eligibility and completing baseline assessments. Researchers, healthcare providers, outcome assessors, and participants will remain fully blinded to group allocation throughout the study. The allocation code will be broken only after data collection is completed and with approval from the ethics committee. This method ensures full allocation concealment and minimizes the risk of selection bias.

This study will employ a double‑blind design. Participants, clinical care providers, investigators, outcome assessors, and data analysts will all be blinded to group allocation. The ginger supplement and placebo will be identical in appearance, smell, packaging, and labeling, and will be distributed in opaque, sealed, and sequentially numbered envelopes. The clinical officer responsible for dispensing the envelopes will not be involved in any aspect of participant assessment, data collection, or analysis. Outcome assessors and laboratory personnel will receive samples and questionnaires labeled only with participant codes, with no indication of intervention status. Data analysts will work with anonymized datasets that contain no allocation information. Unblinding will occur only after completion of data collection and with approval from the ethics committee. This procedure ensures full blinding of all key study personnel and minimizes performance and detection bias.

De-identified Individual Participant Data (IPD), study protocol, statistical analysis plan (SAP), informed consent form, statistical analysis codes, and data dictionary. These materials include de-identified participant-level data, the final protocol, SAP, shareable informed consent form, analysis scripts (without raw data), and the coding structure used in the study. All IPD will be provided only in fully anonymized form.

Data and documents will be available starting 6 months after publication of the primary results and will remain accessible for at least 5 years thereafter.

Qualified researchers affiliated with academic, clinical, or recognized research institutions may request access.

Data may be used only for valid scientific research and secondary analyses. Applicants must: Submit a clear research proposal Sign a data use and confidentiality agreement Agree not to re-identify participants or share the data with others.

Name: Maziar Ghasemi Faculty: School of Nutrition and Food Sciences University: Isfahan University of Medical Sciences, Hezarjarib St., Isfahan, Iran Email: maziar_gh@nutr.mui.ac.ir Alternative email: Maziar.dietitian@gmail.com Phone (optional): +98 921 844 8305

Within 2–4 weeks after receiving a request: The research proposal is reviewed by the study team Ethical compatibility is assessed A Data Use Agreement must be signed De-identified data are prepared and shared via a secure platform

Additional supporting documents may be provided upon justified request.