The Chamorro people once had an incidence rate of ALS-parkinsonism dementia complex that was 50 to 100 times higher than the rate of ALS elsewhere. The decline in the incidence of ALS/PDC among the Chamorro mirrored the decline of the population of flying foxes (a type of bat), by the 1960s and 1970s.
Researchers report in the August 12 issue of Neurology that skin tissues of the flying foxes contained elevated quantities of BMAA (-methylamino-L-alanine), a non-protein amino acid that has shown to kill neurons in cell culture, and is believed to be a possible cause of ALS/PDC.
Once readily available and consumed by the Chamorro, native flying foxes in Guam are now an endangered species. Therefore researchers Paul Alan Cox, PhD, and Sandra A. Banack, PhD, at the Institute for Ethnobotany, National Tropical Botanical Garden in Kauai, Hawaii, turned to bat skin specimens from Guam now housed at the Museum of Vertebrate Zoology at the University of California at Berkeley, to measure the concentration of BMAA.
The skins contained a high concentration of BMAA ranging from 1,287 ug/g to 7,502 ug/g. For comparison, the researchers also analyzed cycad plant seeds for their toxicity because they were an important part of the diets of both the flying foxes and the Chamorro. Although cycad seeds contain BMAA, the concentrations of the neurotoxin in processed cycad flour is believed to be too low to be toxic, and therefore their consumption was not associated with immediate ill effects. Compared to the high conce
Contact: Marilee Reu
American Academy of Neurology