Dementia remains one of the greatest constraints on human longevity. For decades, it has been understood primarily as a disease of dying brain cells—an inevitable consequence of ageing. That view is now being transformed. Emerging evidence shows that dementia is, in large part, a disorder of brain cell repair and maintenance, not simply cell death. Crucially, this process begins early in life, long before symptoms appear. This re-framing changes everything: it suggests that dementia may not be an unavoidable fate of old age, but a preventable condition. In this new paradigm, longevity and mental clarity can coexist—offering a far more hopeful future for ageing well. Dr. Steve Allder is a Consultant Neurologist at Re:Cognition Health and a trailblazer in the evolving landscape of brain health. With over two decades of experience, he is recognised for his expertise across the full spectrum of neurological disorders including dementia, migraine, neurological pain, traumatic brain injury (TBI) and functional neurological disorders (FND). He leads advanced clinical and medicolegal services spanning civilian, military and sports-related neurological injury, and is at the forefront of integrating neuroscience, psychiatry and technology to deliver better outcomes. A passionate advocate for innovation, Dr Allder is the Principal Investigator on several global trials in Parkinson’s disease and has led pioneering research in collaboration with King’s College Hospital, the Aston Brain Centre and the University of York. His work is reshaping how we diagnose and treat conditions like mild TBI, using neuro-computational models and sophisticated imaging techniques such as MEG and high-resolution MRI. A founding member of the FND Society, Dr Allder has contributed extensively to building new clinical frameworks for complex neurological care. With dozens of publications and global collaborations, he remains committed to advancing early detection and treatment strategies for cognitive disorders and chronic neurological conditions. A former NHS neurologist with a background in acute care and neuro-otology, Dr Allder combines clinical depth, academic rigour and a visionary approach to understanding and treating the injured, and ageing, brain. This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at https://www.ted.com/tedx