Ketogenic interventions restore cognition and modulate peripheral metabolic dysfunctions in Alzheimer's disease mouse models

Lifestyle factors modulate dementia risk. We investigated mechanisms of dementia risk reduction by emerging dietary ketogenic interventions. We show that distinct interventions, a medium-chain triglycerides (MCT)-enriched diet and a carbohydrate-free, high-fat diet (CFHF), improve cognition and dendritic spine density of memory-associated hippocampal neurons in two mouse models of Alzheimers disease (AD). Only the CFHF diet drove increased circulating ketones, suggesting distinct underlying mechanisms. AD mice exhibited baseline and diet-induced susceptibility to peripheral metabolic disturbances that were improved by MCT and exacerbated by CFHF diets. Prominent AD-associated dysregulation of the liver transcriptome was largely restored by both interventions, but MCT also downregulated lipogenic enzymes and did not trigger a CFHF-like inflammatory signature. Novel AD- and diet-induced plasmatic changes in hormones and lipid species were identified. Thus, different ketogenic interventions yield cognitive benefits in AD models while showing intervention-specific modulation of peripheral metabolic defects, with implications for design of therapeutic ketogenic strategies.