Amyloid Beta Revisited: A Versatile Immune Polypeptide

Alzheimer's disease affects about fifty million people worldwide. Its main symptoms are the formation of amyloid deposits and of neurofibrillary tangles, and cognition loss. To date, no clear etiology for this disease could be identified. Metal ions have been shown to accumulate in amyloid deposits. Moreover, multiple infections have been shown to be risk factors for the development of Alzheimer's and other dementia, with vaccines playing protective roles. I will here elaborate on the likelihood that Amyloid b is not a toxic molecule, but a protective protein fragment, targeted both against infections and metals. A combination of chemical and biological exposures, with metals playing a key role, would thus be key factors in the triggering of Alzheimer's disease.