Was Lou Gehrig's ALS Caused by Drinking Water?
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Much work remains to be done, but the scientists working on Cox and Banack’s hypothesis believe that normal metabolic processes should allow most people to metabolize and excrete small amounts of BMAA. But some individuals don’t metabolize or excrete BMAA, which could allow it to accumulate in their nerve cells. And that, if Cox and his team are right, could lead to ALS and other neurodegenerative diseases.
Based on recent discoveries, Phase II clinical trials are underway to see if a zinc-based drug could remove BMAA from the body and slow the progression of ALS, bringing hope to victims of a disease that has given them little reason for optimism.
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While Banack shows me how researchers at the institute test for BMAA using a machine called a triple quadrupole mass spectrometer, my mind wanders to how I might be exposed to the toxin — in drinking water, seafood, milk from cows eating pastures irrigated with pond-scum-laden water, spirulina in my protein shakes. I ask about blue-green algae supplements. “Our official policy is that we do not test them,” she says, choosing her words carefully. She refers me to a 2008 paper by Dan Dietrich from the International Symposium on Cyanobacterial Harmful Algal Blooms; he found large quantities of BMAA in commercially sold supplements, including ones containing spirulina and Aphanizomenon flos–aquae.
Cox and Banack have tested, but not yet published, data on several food items. “We are very interested in shellfish as a possible route of exposure, because an oyster can filter 4 to 8 liters of water a minute. They’re amazing indicators of waterborne toxins. They’re like canaries in the mine shaft,” says Cox. “The danger, if there is one, is in consuming shellfish from cyanobacterially contaminated habitats. But if you’re eating from a pristine habitat, you are OK.” I point out that people usually don’t know what kind of water their seafood comes from. Cox suggests that warnings could help. The government already warns people to avoid eating fish caught in mine-tailing areas and to avoid shellfish at certain times of year because of toxins; similar warnings could work for areas with cyanobacterial blooms or high BMAA levels.
In 2009, Larry Brand, a marine biologist at the University of Miami, published a study showing extreme BMAA levels in bottom-feeding species off Florida’s coast, where a massive cyanobacterial bloom exists. Pink shrimp, blue crabs, and species that feed on the ocean floor had the highest levels; people eat some of those species. Brand and Deborah Mash have since found BMAA in the brains of dolphins as well as in fins of several shark species, organisms at the top of the food chain. Meanwhile, European researchers have documented biomagnification of BMAA in Baltic Sea aquatic life.
“As the dose goes up, our data suggests that incidence [of ALS] also goes up,” says Cox. “If people are consuming a BMAA-rich diet, there’s more chance they are going to fall ill. People need to be very careful about the water they’re drinking.” Neurologist Elijah Stommel of Dartmouth-Hitchcock Medical Center has linked clusters of ALS cases in the same zip code, or even the same street or building, to exposure to cyanobacteria-contaminated lakes in New Hampshire, Vermont, and Maine. Stommel is building a geographic database of ALS cases in the northeastern U.S.; it already includes more than 800 cases.
Do standard water-treatment methods remove BMAA? Only one study has been conducted so far. A graduate student who works with microbiologist Tim Downing at Nelson Mandela Metropolitan University Summerstrand campus in Port Elizabeth, South Africa, found that standard water-treatment methods, including sand filtration, powdered activated carbon (a bit like what’s found in a Brita filter), and chlorination, were particularly successful at removing BMAA. Flocculation, sometimes called coagulation, in which particles are allowed to settle and then made to cluster so that they can be separated from drinking water, was not as effective.