Lipids are vital constituents of cell membranes and have been shown essential for synaptic formation and remodeling. These processes are crucial for learning, formation of memories and neuronal repair, all of which are progressively impaired during normal and pathological aging, especially in dementias of the Alzheimer''s disease (AD) type. Across the globe, interest in research on the interconnections between the lipidic system and AD is growing. Based on pathologic and genetic findings, this book explores the possible roles of paraoxonase 1 in AD, an antioxidant enzyme found on lipoprotein particles transporting lipids to neurons. Of interest to scholars, the current book also provides a comprehensive up-to-date review of the role of brain lipid metabolism in the pathogenesis of AD.