The Effect of Chronic Inflammation and Oxidative Stress on Alzheimer's Disease Progression: A Systematic Review

Alzheimer's Disease (AD) is known to be the most common type of dementia among older adults. It is characterized by a gradual decline in cognitive abilities, particularly the deterioration of short-term memory. The hallmark neuropathology of AD is the accumulation of neurofibrillary tau tangles (NFTs), which consist of hyperphosphorylated tau protein, as well as extracellular beta-amyloid plaques in the brain. Evidence suggests that AD is not solely tied to neurological mechanisms, and that other factors, such as inflammation, can affect disease progression, including systemic inflammation seen in metabolic syndrome and oxidative stress. We performed a literature review by searching databases and conducting a manual search of studies regarding the relationship between AD, inflammation, and oxidative stress, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After meticulous scrutiny and the application of inclusion and exclusion criteria to clinically relevant papers, 14 studies were deemed relevant for this review regarding the effect of inflammation and oxidative stress in relation to AD and its progression. The findings conclude that there is new evidence supporting the theory that chronic inflammation plays a significant role in the progression of the disease, which could allow for future advancements in treatments, diagnostics, and preventive tools for its management. These advancements could include the implementation and use of biomarkers for inflammation, the use of algorithms to stratify the disease's grade, and the use of mineral supplements like zinc. Furthermore, the management of underlying conditions has been shown to be beneficial in slowing the progression of AD.