Abstract

A common form of dementia, especially among the elderly, is Alzheimer’s disease. Neurodegeneration and progressive cognitive decline are its hallmarks. The exact cause of Alzheimer’s disease is still unknown, despite numerous studies. Several theories have been proposed, including tau protein hyper-phosphorylation and A amyloid deposition in the brain. This survey article investigates the possible pathogenesis of Alzheimer’s illness, zeroing in on the impacts of disturbances in the degrees of vitamin B12, folate, and homocysteine, as well as the effect of oral microorganisms causing periodontitis and insulin opposition, and their relationship to Alzheimer’s. High homocysteine levels and low folate and vitamin B12 levels have been linked to an increased risk of Alzheimer’s disease, according to research. The article also looks into the connection between oral bacteria and Alzheimer’s disease, specifically dental infections and periodontitis, which contribute to the inflammatory processes in Alzheimer’s patients’ nervous systems.