Introduction
This book provides a comprehensive and mechanistic overview of how exposure to toxic metals contributes to the onset and progression of neurodegenerative diseases. It integrates evidence from molecular biology, toxicology, neuroscience, and epidemiology to explain how both essential metals (e.g., iron, copper, zinc) and non-essential toxic metals (e.g., lead, mercury, cadmium, arsenic) influence brain health.
A central theme of the book is that while metals are crucial for normal neuronal function—supporting enzymatic activity, neurotransmission, and cellular homeostasis—imbalances or excessive accumulation in the brain become pathogenic. The text emphasizes that metal dysregulation disrupts key cellular processes, including mitochondrial function, redox balance, and protein folding, ultimately leading to neuronal injury.
Mechanistically, the book highlights several converging pathways through which metals drive neurodegeneration:
• Oxidative stress and reactive oxygen species (ROS) generation, leading to lipid, protein, and DNA damage
• Mitochondrial dysfunction, impairing energy metabolism and promoting apoptosis
• Protein misfolding and aggregation, contributing to hallmark pathologies such as amyloid plaques, tau tangles, and α-synuclein accumulation
• Neuroinflammation, involving activation of microglia and astrocytes
• Disruption of neurotransmission and synaptic integrity, resulting in cognitive and motor deficits
The book also explores how chronic and low-dose exposure to metals can produce latent and progressive neurotoxicity, meaning that damage may accumulate silently over time and manifest later in life as diseases such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis.
Importantly, it discusses the interaction between genetic susceptibility and environmental exposure, suggesting that metals can exacerbate existing vulnerabilities in neuronal systems. The role of the blood–brain barrier and metal transport systems in regulating brain metal homeostasis is also examined.
Finally, the book addresses therapeutic and preventive strategies, including metal chelation, antioxidant approaches, and restoring metal homeostasis, while emphasizing the need for further research to fully understand disease-specific mechanisms and improve clinical interventions.
In essence, the book positions neurotoxic metals as critical environmental and biological factors that act through interconnected molecular pathways to drive progressive neurodegeneration, offering insights that are vital for both understanding disease mechanisms and developing targeted therapies.