From Refractory Epilepsy to Neurodegeneration: Emerging Mechanistic and Clinical Insights Into the Ketogenic Diet.

The ketogenic diet (KD), a high-fat, low-carbohydrate intervention, is well established for drug-resistant epilepsy and is increasingly explored in neurodegenerative disorders. KD reduces neuronal hyperexcitability through enhanced γ-aminobutyric acid (GABA)ergic transmission and modulation of neurotransmitter balance, underlying its efficacy in refractory epilepsy. Beyond seizure control, emerging evidence suggests KD may influence disease processes in conditions such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and Huntington's disease. Preclinical studies indicate that KD can modulate mitochondrial bioenergetics, oxidative stress, neuroinflammation, neurotransmitter signaling, and gut-brain interactions, though these effects are highly context-dependent and primarily derived from cellular and animal models. Clinical data remain limited, heterogeneous, and short-term, with small cohorts and variable outcome measures. Sustaining adherence and assessing long-term safety remain significant challenges in patient populations. This review summarizes recent experimental and clinical findings, highlighting the molecular and cellular mechanisms through which KD exerts neuroprotective effects. We also evaluate translational evidence and discuss the potential utility of KD as an adjunctive intervention in neurological disease management.