Metabolic therapeutic targets in Alzheimer's disease

Alzheimer's disease (AD) is increasingly recognized as a disorder marked not only by amyloid-β and tau pathology, but also by profound disturbances in brain energy metabolism that arise early in disease progression. Accumulating evidence indicates that impairments in glucose utilization, insulin signaling, and mitochondrial function precede neurodegeneration and contribute directly to synaptic failure and cognitive decline. This chapter presents a comprehensive overview of Alzheimer's disease through the lens of metabolic dysfunction, highlighting disrupted neuronal bioenergetics as a central and unifying feature of pathogenesis. We examine key metabolic pathways implicated in AD, including cerebral glucose hypometabolism, brain insulin resistance, impaired glycolysis, mitochondrial oxidative phosphorylation deficits, oxidative stress, and altered mitochondrial dynamics. The chapter further discusses therapeutic strategies aimed at restoring metabolic homeostasis, such as insulin sensitization, enhancement of glucose transport, activation of mitochondrial biogenesis, modulation of the electron transport chain, and the use of mitochondria-targeted antioxidants. In parallel, alternative energy approaches-including ketone metabolism, fatty acid oxidation, and pentose phosphate pathway activation-are explored as promising avenues to bypass glucose-dependent energy deficits and reinforce neuronal resilience. Emerging directions in metabolic therapeutics are also highlighted, including combination treatment strategies, NAD⁺-sirtuin and AMPK signaling, and the expanding role of the gut microbiome-brain metabolism axis. By integrating insights from experimental models, neuroimaging studies, and clinical trials, this chapter underscores the potential of metabolic interventions to enable early, disease-modifying strategies for Alzheimer's disease.