This book discusses the mechanism and therapeutic strategies of phytochemicals against brain ageing. It discusses the underlying anti-oxidative and anti-inflammatory mechanisms of the phytochemicals and the implications of these compounds in the prevention and treatment of geriatric diseases. It discusses the potential role of the highly complex interactive network between the gut and the brain in neurodegenerative diseases such as Parkinson’s disease (PD), and Alzheimer’s disease. The chapters provide insight into the mechanisms involved in brain ageing and the mechanism of actions of the phytochemicals that might be crucial in developing effective new therapies against brain ageing. The chapter also presents the mechanisms of action of phytoconstituents, bioavailabilities, and their effects on neuroinflammation. The chapters also examine the phytochemicals protection of neurons via targeting oxidative stress, mitochondrial dysfunction, neurotrophic factor deficit, apoptosis, and abnormal protein accumulation. This book aims to provide comprehensive and cutting-edge information on the potential neuroprotective role of phytochemicals on the brain and neurological disorders to researchers, neuroscientists, clinical nutritionists, and physicians.