title: Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain.
abstract: Neurofibrillary tangles (NFT) and β-amyloid plaques are the neurological hallmarks of both Alzheimer's disease and an unusual paralytic illness suffered by Chamorro villagers on the Pacific island of Guam. Many Chamorros with the disease suffer dementia, and in some villages one-quarter of the adults perished from the disease. Like Alzheimer's, the causal factors of Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) are poorly understood. In replicated experiments, we found that chronic dietary exposure to a cyanobacterial toxin present in the traditional Chamorro diet, β-N-methylamino-l-alanine (BMAA), triggers the formation of both NFT and β-amyloid deposits similar in structure and density to those found in brain tissues of Chamorros who died with ALS/PDC. Vervets (Chlorocebus sabaeus) fed for 140 days with BMAA-dosed fruit developed NFT and sparse β-amyloid deposits in the brain. Co-administration of the dietary amino acid l-serine with l-BMAA significantly reduced the density of NFT. These findings indicate that while chronic exposure to the environmental toxin BMAA can trigger neurodegeneration in vulnerable individuals, increasing the amount of l-serine in the diet can reduce the risk.
authors.affiliation: Institute for Ethnomedicine, Jackson Hole, WY, USA paul@ethnomedicine.org.
authors.forename: Paul Alan
authors.initials: PA
authors.lastname: Cox
authors.affiliation: Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Davis
authors.affiliation: Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA.
authors.forename: Deborah C
authors.initials: DC
authors.lastname: Mash
authors.affiliation: Institute for Ethnomedicine, Jackson Hole, WY, USA.
authors.forename: James S
authors.initials: JS
authors.lastname: Metcalf
authors.affiliation: Institute for Ethnomedicine, Jackson Hole, WY, USA.
authors.forename: Sandra Anne
authors.initials: SA
authors.lastname: Banack
mesh_terms: D000599:Amino Acids, Diamino / Q000737:chemistry / Q000633:toxicity*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000690:Amyotrophic Lateral Sclerosis / Q000139:chemically induced* / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D000818:Animals; D001921:Brain / Q000187:drug effects*; D002522:Chlorocebus aethiops; D000087522:Cyanobacteria Toxins; D005506:Food Contamination; D006141:Guam; D006801:Humans; D016874:Neurofibrillary Tangles / Q000473:pathology*; D018517:Plant Roots / Q000382:microbiology; D044382:Population Groups; D012694:Serine / Q000494:pharmacology
chemical_list: D000599:Amino Acids, Diamino; D016229:Amyloid beta-Peptides; D000087522:Cyanobacteria Toxins; C001824:beta-N-methylamino-L-alanine; D012694:Serine
keywords: Alzheimer's; BMAA; amyotrophic lateral sclerosis; cyanobacteria; l-serine; tau