By Nicholas Preston (UW-Madison)
A new publication contributes additional evidence for the connection between naturally-occurring neurotoxins, produced by cyanobacteria, and neurodegeneration in vulnerable humans (Pablo and others 2009).
Cyanobacteria, sometimes described as blue-green algae, are ubiquitous in freshwater, marine and terrestrial systems, where they produce the neurotoxic amino acid b-N-methylamino-l-alanine (BMAA) as a chemical defense against predators.
A new publication contributes additional evidence for the connection between naturally-occurring neurotoxins, produced by cyanobacteria, and neurodegeneration in vulnerable humans (Pablo and others 2009).
Cyanobacteria, sometimes described as blue-green algae, are ubiquitous in freshwater, marine and terrestrial systems, where they produce the neurotoxic amino acid b-N-methylamino-l-alanine (BMAA) as a chemical defense against predators.
The co-occurrence of BMAA in brain tissue from patients with Alzheimer's, Lou Gehrig's, and Huntington's disease, suggests the BMAA in the environment may trigger the onset of these diseases (Papapetropoulos 2007, Pablo and others 2009). There is controversy over the connection, stemming from early work on cyanobacteria in the diet of the Chamorro people of Guam and elevated incidence of neurodegenerative disease (Cox and others 2003). Indeed, the debate continues as to whether the pathway for the toxin in Guam involves contaminated water, tortillas or biomagnification in flying foxes (Borenstein and others 2009).
In a recent interview with the Boston Globe, Paul Cox, a botanist at the Institute for Ethnomedicine and one of Time's "Heroes of Medicine," urged caution, particularly in light of the discovery of an increased occurrence of Lou Gehrig's among people living near lakes with cyanobacterial blooms in New Hampshire. Cox emphasized that the disease involves both environmental triggers and genetic pre-disposition.
Harmful algal blooms, such as those of cyanobacteria, are often attributed to anthropogenic eutrophication--nutrient enrichment of aquatic ecosystems by humans (Smith and Schindler 2009). Phosphorus availability limits algal growth in many lakes, such that additional inputs from fertilizers and detergents can stimulate blooms.
Cyanobacteria, in particular, are able to take advantage of phosphorus inputs as they can fix atmospheric nitrogen, thereby satisfying their metabolic needs and allowing them to out-compete other algal species that do not have a mechanism for fixing nitrogen. These anthropogenic inputs of phosphorus can persist for decades through internal nutrient cycles, posing long-term ramifications for public health.
The Center for Disease Control provides additional information on cyanobacteria, including precautionary recommendations.
Harmful algal blooms, such as those of cyanobacteria, are often attributed to anthropogenic eutrophication--nutrient enrichment of aquatic ecosystems by humans (Smith and Schindler 2009). Phosphorus availability limits algal growth in many lakes, such that additional inputs from fertilizers and detergents can stimulate blooms.
Cyanobacteria, in particular, are able to take advantage of phosphorus inputs as they can fix atmospheric nitrogen, thereby satisfying their metabolic needs and allowing them to out-compete other algal species that do not have a mechanism for fixing nitrogen. These anthropogenic inputs of phosphorus can persist for decades through internal nutrient cycles, posing long-term ramifications for public health.
The Center for Disease Control provides additional information on cyanobacteria, including precautionary recommendations.