Do you wonder if there are any parasites in the fresh fish you're about to eat? How about in your sushi or sashimi? A recent study found that almost all tuna (53 skipjack tuna) caught recently off the cost of southern Brazil contained parasites.
While it is unknown what is in the tuna that you may be about to eat, the researchers say that cooking the fish kills all parasites. Parasites are also killed during canning. By the way, it is unknown what the fish from other parts of the world may contain.
From Science Alert: Scientists Find Parasites in Almost Every Fish From a Recent Tuna Haul – 96% Were Infected
A fatty tuna that is often used for sashimi or canning may be swimming with parasites more often than not.
When scientists at the Federal University of Santa Catarina in southern Brazil analyzed 53 locally caught fish, they found nearly all were contaminated by worms.
The tuna species analyzed in the study is known as skipjack, oceanic bonito, or katsuo (Katsuwonus pelamis), depending on where you are in the world, and it has high commercial value.
Tuna sold for consumption is usually carefully examined by seafood processors and sushi chefs, and visible parasites are thankfully removed. But the truth is that some tiny creatures inevitably sneak past our defenses .Indeed, parasitologists in the United States are studying worms hidden in expired cans of fish to track parasite numbers.
That said, if eaten in raw or undercooked fish, some species can latch onto the human intestinal wall and cause gastrointestinal symptoms such as abdominal pain, vomiting, nausea, or diarrhea.
Even if these parasites don't make someone sick, though, finding a worm in a can of tuna is enough to turn some consumers away.
At this point, it's impossible to say whether this many parasitic worms in tuna is normal.
On average, they explained, we have gone from finding less than one worm in every 100 caught fish to more than one worm in every single host caught.
More research needs to be done tracking parasites, not only off the coast of Brazil, but in other key fishing regions around the world, to better understand how they are faring in a rapidly changing world.