Calcium and Aluminium in the Chamorro Diet: Unlikely Causes of Alzheimer-Type Neurofibrillary Degeneration on Guam

Abstract

The 15 small islands of the Marianas comprise an archipelago that stretches northwards from Guam to Japan. For more than a century, the indigenous population of the Mariana Islands has been susceptible to a progressive fatal paralysis, beginning in adult life. This disorder is a neurodegenerative disease that the Marian people call Lytico-Bodig and which Kurland and colleagues termed the amyotrophical lateral sclerosis/parkinsonism-dementia complex of Guam (ALS/PDC) (Elizan et al. 1966). Initially, aggregations of ALS/PDC in certain Chamorro families suggested that the disease might be inherited (Kurland and Mulder 1954). However, a steady decline in the annual incidence of ALS/PDC since the early 1960s, and its occurrence among non-Chamorro immigrants to Guam indicate that the cause is environmental, and associated with a long latency from the initial exposure to the causative agent or agents and development of the disease (Reed et al. 1975; Garruto et al. 1985; Plato et al. 1986). There are two other foci of ALS/PDC, one in the Kii Peninsula of Japan (Shiraki and Yase 1975) and the other in western New Guinea (Gajdusek 1963). Because these three locales are geographically, ethnically and culturally distinct, investigators have sought shared factors which could explain the presumed common aetiology and pathogenesis of the disease in these different regions of the world.