Ketogenic Diet and Neurological Health: A Narrative Review with Natural Language Processing-Assisted Thematic Mapping Using BERTopic.

BACKGROUND

The ketogenic diet (KD) is an established therapy for drug-resistant epilepsy and is increasingly investigated across other neurological disorders.

OBJECTIVE

To provide an updated narrative synthesis of recent mechanistic and clinical evidence on KD across neurological disorders, including its therapeutic applications, potential mechanisms, and current evidence gaps, and to use BERTopic as a supplementary natural language processing tool to characterize major research themes and temporal changes in research emphasis.

METHODS

Literature published from 2021 to early 2026 was retrieved from Scopus, Web of Science, and PubMed. After deduplication and eligibility screening, 1017 records were included in BERTopic analysis. PubMedBERT, UMAP, HDBSCAN, and c-TF-IDF were used for thematic mapping; interpretation and evidence synthesis remained expert-guided. Temporal analyses were restricted to 2021-2025.

RESULTS

Seven thematic clusters were retained, with increased representation of gut-brain-axis-related publications after 2023. Narrative synthesis highlighted energy metabolism, mitochondrial function, oxidative stress, neuroinflammation, neurotransmitter regulation, and the gut-brain axis as major mechanistic domains. Clinical evidence was strongest for drug-resistant epilepsy, while findings for Alzheimer's disease and migraine were less mature and those for Parkinson's disease remained preliminary.

CONCLUSION

KD is an established therapy for drug-resistant epilepsy and shows potential across other neurological disorders, particularly Alzheimer's disease and migraine. Its effects may involve energy metabolism, mitochondrial function, oxidative stress, neuroinflammation, neurotransmitter regulation, and the gut-brain axis. BERTopic-assisted mapping complemented the narrative synthesis by summarizing major research themes and temporal trends.