Dietary supplements and bioactive compounds for managing Parkinson's Disease

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by dopaminergic neuronal loss and multisystem pathology involving oxidative stress, mitochondrial impairment, neuroinflammation, proteostasis disruption with α-synuclein aggregation, and gut–brain axis dysfunction. Levodopa remains the most effective symptomatic therapy, yet it does not directly target upstream pathogenic processes and may be limited by long-term complications, motivating interest in adjunct strategies that support multiple disease-relevant pathways. This review integrates mechanistic, preclinical, and clinical evidence on dietary supplements, functional food–derived nutrients, and bioactive compounds that may complement standard pharmacotherapy in PD. A structured search of major scientific databases was conducted to identify studies relevant to PD pathology, with findings synthesized qualitatively using a pathway-based framework that includes proteostasis and α-synuclein biology, mitochondrial bioenergetics and mitophagy, oxidative stress responses, neuroinflammatory signaling, neurotrophic support, and gut–brain communication. Across compound classes, polyphenols, omega-3 fatty acids, mitophagy-associated metabolites, and neurotrophic modulators show consistent mechanistic relevance in experimental models, while human data is still emerging and heterogeneous across study designs, formulations, and outcome measures. Overall, the evidence supports nutraceuticals and functional food–derived bioactives as potential adjuncts—not replacements—to established PD therapies, with translational progress dependent on improved standardization of formulations, bioavailability considerations, and long-term trials using clinically interpretable endpoints.  Novelty of the Study: This review synthesizes dietary supplements, functional food–derived nutrients, and bioactive compounds in Parkinson’s disease (PD) using a multi-pathway framework aligned with Functional Food Science (FFS), linking mechanistic plausibility to translational biomarkers and clinically relevant outcomes. To our knowledge, this is the first structured analysis integrating PD pathology with the FFC functional food development model, including bioactive compound identification, biomarker mapping, and adjunct therapeutic potential. Keywords: Parkinson’s disease; nutraceuticals; bioactive compounds; functional foods; oxidative stress; mitochondrial dysfunction; neuroinflammation; α-synuclein; proteostasis; mitophagy; gut–brain axis; adjunct therapy