Neurodegenerative diseases of protein misfolding affect humans and animals. In humans, these diseases include Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Western Pacific amyotrophic lateral sclerosis and Parkinsonism-dementia complex (ALS/PDC). Mineral exposure may be important in the pathogenesis of protein misfolding cascades. The possible association of bentonite, montmorillonite, and mineral risk factors with Alzheimer’s disease, Parkinson’s disease, ALS, and Western Pacific ALS/PDC is analyzed and discussed.