Shark Fins, Meat Should Never Be Eaten: High Concentration of Neurotoxins Found in Sharks

A new study suggests that the restrictions imposed in consuming sharks fins and meats are not only there for shark conservation, but also to protect the health of the consumers.

The study, published in the journal Toxins, revealed that fins and muscles of sharks could contain high concentrations of toxins linked to neurodegenerative diseases in humans.

"Since sharks are predators, living higher up in the food web, their tissues tend to accumulate and concentrate toxins, which may not only pose a threat to shark health, but also put human consumers of shark parts at a health risk," explained Neil Hammerschlag, a research assistant professor at the UM Rosenstiel School and UM Abess Center for Ecosystem Science and Policy and lead author of the study, in a press release.

For the study, the researchers collected fin and muscle tissue samples from 10 shark species living in the Pacific and Atlantic Oceans. Among the 55 samples analyzed, high levels of β-N-methylamino-L-alanine (BMAA) were detected in 48 samples. Additionally, high levels of mercury were also detected in all the samples.

BMMA is believed to be associated with the development of neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis (ALS). On the other hand, Mercury could affect the central and peripheral nervous systems leading to possible neurological and behavioral disorders. The toxins are very dangerous on their own. However, the researchers warned that the being exposed to both of them at the same time could produce synergistic toxic impacts.

Shark fins and meats are widely consumed in Asia and Asian communities worldwide. Its cartilages are also being used as ingredient for dietary supplements consumed globally.

Due to their exotic taste and uses in traditional Chinese medicines, excessive capture and trade of sharks caused their global population to plummet down. About 64 shark species were considered to be Endangered in the International Union for Conservation of Nature (IUCN) Red List, including the great hammer head shark and speartooth shark.