Intermittent Fasting Reprograms the Brain Proteome to Prevent Synaptic Degeneration and Cognitive Impairment in Vascular Dementia

Vascular dementia (VaD), driven by chronic cerebral hypoperfusion (CCH), leads to synaptic degeneration and cognitive decline, yet mechanisms linking vascular dysfunction to synaptic loss remain unclear. Intermittent fasting (IF) has emerged as a potential intervention, but its effects on synaptic integrity in VaD are unknown. Using the bilateral common carotid artery stenosis (BCAS) mouse model, we demonstrate that a 16-hour IF regimen preserves cognitive function and cortical synaptic density despite persistent hypoperfusion. Behavioral assays revealed that IF prevented spatial memory deficits in BCAS mice, while electron microscopy confirmed synaptic preservation without altering baseline architecture. Surprisingly, synaptic protein levels remained unchanged, suggesting IF protects synaptic function rather than abundance. Proteomic profiling uncovered dynamic hippocampal adaptations under IF, including upregulation of synaptic stabilizers, enhanced GABAergic signaling, and suppression of neuroinflammatory mediators. IF also attenuated microglial engulfment of synapses, indicating modulation of complement-mediated pruning. Temporal pathway analysis revealed IF’s multi-phase neuroprotection: early synaptic reinforcement, mid-phase metabolic optimization, and late-phase suppression of chronic neuroinflammation. These findings establish IF as a potent modulator of synaptic resilience in VaD, acting through coordinated preservation of synaptic structure, inhibition of inflammatory synapse loss, and metabolic reprogramming. Our results highlight IF’s potential as a non-pharmacological strategy to combat vascular cognitive impairment by targeting the synaptic vulnerability underlying dementia progression.