Sharks are among the most threatened of marine species worldwide due to unsustainable overfishing. They are primarily killed for their fins to fuel the growing demand for shark fin soup, which is an Asia delicacy. A new study by University of Miami (UM) scientists in the journal Marine Drugs has discovered high concentrations of BMAA in shark fins, a neurotoxin linked to neurodegenerative diseases in humans including Alzheimer’s and Lou Gehrig Disease (ALS). The study suggests that consumption of shark fin soup and cartilage pills may pose a significant health risk for degenerative brain diseases.
In a new study by University of Miami marine biologist Neil Hammerschlag and Deborah Mash, M.D., uncover an alarming accumulation of BMAA neurotoxins in shark fins, which may pose a serious threat to shark fin consumers. (C
Seven species of shark were tested for this study: blacknose, blacktip, bonnethead, bull, great hammerhead, lemon, and nurse sharks. Samples were collected from live animals in waters throughout South Florida.
“The concentrations of BMAA in the samples are a cause for concern, not only in shark fin soup, but also in dietary supplements and other forms ingested by humans,” says study co-author Prof. Deborah Mash, Director of the UM Miami Brain Endowment Bank. The Bank supports basic and clinical research and holds one of the world’s largest collection of postmortem human brains encompassing a wide range of neurological disorders. In 2009, Mash and her co-authors published a study in the journal Acta Neurological Scandinavica, demonstrating that patients dying with diagnoses of Alzheimer’s Disease and ALS had unusually high levels of BMAA in their brains, up to 256 ng/mg, whereas normal healthy aged people had no BMAA or only trace quantities of the toxin present. “BMAA was first linked to neurodegenerative diseases in Guam, which resulted in the progressive loss of structure and function of neurons.”
The shark study found a similar range and even higher BMAA in the fins tested, levels of between 144 and 1836 ng/mg of BMAA, which overlapped the levels measured in the brains of the Alzheimer’s and ALS victims. Coincidentally, this level fits with the BMAA levels in fruit bats examined by Paul Cox in Guam, animals which concentrate BMAA from their diet of cycad seeds. He linked ingestion of fruit bats to the severe ALS/Parkinsonism dementia that afflicted local indigenous people.
“Not only does this work provide important information on one probable route of human exposure to BMAA, it may lead to a lowering of the demand for shark fin soup and consumption of shark products, which will aid ocean conservation efforts,” added Hammerschlag.
The project was funded through a donation from the Herbert W. Hoover Foundation. Established in 1990, the foundation takes a leadership role in supporting unique opportunities that provide solutions to issues related to the community, education, and the environment.
The above story is reprinted from materials provided by University of Miami, Rosenstiel School of Marine and Atmospheric Science, via Newswise.
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- Kiyo Mondo, Neil Hammerschlag, Margaret Basile, John Pablo, Sandra A. Banack, Deborah C. Mash. Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA) in Shark Fins. Marine Drugs, 2012; 10 (2): 509 DOI: 10.3390/md10020509