Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338
April 05, 2005
Scientists Find Link Between Bacteria, Neurological Disorders
A University of Guelph scientist is part of an international research team that has found a link between a common type of bacteria found worldwide and neurological disorders such as Alzheimer’s, Parkinson’s and Lou Gehrig’s disease.
Susan Murch, a research associate in Guelph’s Department of Plant Agriculture, is part of a research team whose findings were published in this week’s Proceedings of the National Academy of Sciences.
The group, led by Paul Alan Cox from the U.S. Institute for Ethnomedicine, does not claim to have pinpointed the cause of neurological diseases in humans. But it did find a neurotoxic amino acid, beta-methylamino-L-alanine (BMAA) — believed to lead to a complex of neurological diseases in humans — in tissues of the indigenous people of Guam and in tissues of Canadian Alzheimer’s patients.
Until recently, the amino acid BMAA was known only to exist in cycads, plants that resemble small palm trees and grow only in warm parts of the world. Cycad seeds are eaten by some indigenous people, including the Chamorro of Guam. The Chamorro have experienced an epidemic of a progressive neurodegenerative disease that scientists refer to as the amyotrophic lateral sclerosis/Parkinsonism-dementia complex (ALS/PDC). In the 1950’s ALS/PDC was 100 times more prevalent in Guam than other similar diseases elsewhere in the world, but the rate has since been declining.
But Murch and the other researchers now report that BMAA is also produced by diverse species of cyanobacteria, or blue-green algae, common in oceans, lakes and soils around the world. BMAA was found in 95 per cent of blue-green algae that they tested.
“This study indicates that human exposure to BMAA may be possible in many places throughout the world,” Murch said.
She said links between toxins produced by cyanobacteria and neurological disorders need to be studied more closely, including everything from toxicity studies to large-scale population screening. The researchers are also suggesting that cyanobacterial contamination of drinking water should be closely monitored.
Work by Murch and other members of the research team is also featured this week in a New Yorker article by Jonathan Weiner about neurological diseases.