Mediterranean Diet Effects on Parkinson's Disease (MED-PARK): a Randomized Controlled Trial
Currently, there are no disease-modifying treatments for Parkinson's disease (PD), the second most common neurodegenerative disorder worldwide, making it crucial to find interventions that can change the disease's trajectory. Epidemiological studies suggest that the Mediterranean diet (MD) is linked to improved motor and non-motor symptoms, slower disease progression, and lower mortality in PD patients. However, few interventional studies have explored this connection. This study assesses whether an MD can improve motor and non-motor symptoms in PD patients. Additionally, the study will examine the effects of the diet on a patient's quality of life, gastrointestinal symptomatology, adaptive immune system, fecal and nasal microbiome, and fecal and urinary metabolomics. This is a randomized, controlled, non-pharmacological, single-center, masked trial with two parallel groups. It will evaluate the safety and efficacy of the MD on motor and non-motor symptoms reported by PD patients. Forty-four participants, aged 40-85, meeting the inclusion criteria will be enrolled and block-randomized into two groups: one maintaining their usual diet (control) and the other following a MD for six months (intervention). The primary outcome is patient-reported symptoms, measured using the MDS-UPDRS I+II score. Secondary outcomes include the analysis of adaptive immune system cells, nasal and fecal microbiome composition, and inflammatory and metabolic markers. Additional assessments include disease severity (MDS-UPDRS), non-motor symptoms (Non-Motor Symptoms Scale), participant well-being (36-Item Short Form Health Survey), gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale and Patient Assessment of Constipation Quality of Life), and the intensity of dopaminergic therapy (levodopa equivalents). Evaluations will be performed at baseline and after six months.
• PD diagnosis according to international guidelines;
• Age between 40 and 85 years;
• Naive to medication or with a stable dosage of anti-Parkinson's therapy for at least two weeks;
• Hoehn \& Yahr stage ≤3;
• Normal independent feeding;
• Ability to complete informed consent;
• Willingness to maintain the usual diet in the period between T0 and T1;
• Willingness to maintain the usual diet if randomized to the control group in the T1-T2 period;
• Willingness to make changes in their diet to follow a Mediterranean diet if randomized to the intervention group in the T1-T2 period;
⁃ Willingness to fill out questionnaires;
⁃ Willingness to provide blood samples during the study collection periods;
⁃ Willingness to provide stool samples during the study collection periods;
⁃ Willingness to fast (without food or drink except water, tea or coffee) at least 12 hours before each sample collection;
⁃ Willingness to discontinue taking supplements, probiotics, herbal or high- dose vitamins or minerals that could impact inflammation during the period between T0 and T1 and for the duration of the study protocol;
⁃ No medical and/or social conditions that could interfere with participation in a six-month interventional study.