A fat chance at neuroprotection: Ketogenic diet and Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by both motor and non-motor symptoms that significantly impair patients' quality of life. While pharmacological therapies provide symptomatic relief, no disease-modifying treatments have been conclusively established. In recent years, there has been increasing interest in non-pharmacological interventions, including dietary strategies, for their potential role in symptom management and disease modification. This literature review aims to examine the emerging role of the ketogenic diet (KD) in the management of PD, exploring its potential to alleviate symptoms and impact disease progression. Preliminary evidence suggests that KD may offer symptomatic benefits in PD through mechanisms such as mitochondrial support, anti-inflammatory effects, neuroinflammation, and impacting gut dysbiosis. Studies have shown promising results, particularly for non-motor symptoms such as urinary function, fatigue and cognition, however consistent improvement in motor outcomes has yet to be demonstrated. It should be noted that existing clinical data are derived from small pilot trials (generally n < 20) with heterogenous dietary protocols and variable ketone targets, limiting definitive conclusions. While the mechanistic rational and early clinical signals are encouraging, larger and longer duration randomized controlled trials with standardized ketogenic protocols are needed to fully characterize KD's potential in PD management.