Nutritional and dietary clinical trials for Parkinson's disease: a narrative review.

This study aims to review clinical trials investigating dietary or nutritional interventions for Parkinson's Disease (PD) and identify potential research gaps. A PubMed search yielded 3378 results, and after applying inclusion and exclusion criteria, 38 studies were selected. Of these, 13 focused on interventions with potential neuroprotective effects against PD, 18 examined symptom improvement, and 7 explored their relationship to antiparkinsonian medication. Most studies were randomized controlled trials (RCTs) and demonstrated promising results. However, they were often limited by small sample sizes and short durations. Large-scale, double-blind, placebo-controlled RCTs are necessary to further investigate the effects of dietary and nutritional interventions in PD. Other nutrients with promising results in preclinical research should be further evaluated in clinical trials. Moreover, research should prioritize dietary pattern interventions, like the Mediterranean and ketogenic diets, while closely monitoring patient adherence to these approaches. Lastly, future research should further explore the role of gut microbiota and its potential pathogenic involvement in PD.