Parasites in Your Sushi: Should You Be Concerned? How to Protect Yourself

Stefan Krasowski of Rapid Travel Chai and I used to meet for lunch at a local restaurant in the Atlanta area where you can eat as much sushi as you want from the buffet for one price. We would get in line, choose the sushi that we wanted to eat, place them on our plates, head back to the table, and discuss weblogs, miles, points and travel. I personally enjoyed the sushi and always left very satisfied. I do miss those lunch meetings…

…but then I came across this discussion on FlyerTalk pertaining to parasites found in sushi, which suggests that the problem may be more common than one might think. The Internet is fraught with stories and videos about how parasites have taken over the bodies of their hosts once ingested — such as this article with an unverified video and this article about a Chinese man whose scans purportedly revealed an infestation of tapeworms throughout his body.

Should you be concerned that parasites in your sushi could happen to you? What can you do to protect yourself?

“Your chances of becoming infected with a parasite in a U.S. sushi bar are so low that it could reasonably be dismissed as an issue in our modern times”, assures Ross Christensen in this article. “Sushi in other countries is still at risk, but many of these other countries are picking up our ‘Freeze the parasites to death’ program. Even sushi bars in Japan, with their obsession of the freshest seafood possible, are becoming safer to eat at.

“So for all of the paranoid, hypochondriac, and doom saying folks who are scared to eat sushi in fear that their body will become the next great rave party for the squirmy wiggly critters, I’m sorry to tell you that America’s professional sushi bars are secured by some of the best bouncers since Patrick Swayze watched over ‘Roadhouse.’”

According to this article, “The health risk from parasites is far less than the risk from ‘unseen’ illness causing bacteria which are present in almost all foods.” It continues on to say that “there should be caution in consuming raw fish because some species of fish can contain these harmful worms. Eating raw, lightly cured, or insufficiently cooked infected fish can transfer the live worms to humans. Most of these parasites cannot adapt to human hosts. Often, if an infected fish is eaten, the parasites may be digested with no ill effects. Adequate freezing or cooking fish will kill any parasites that may be present. Raw fish (such as sushi or sashimi) or foods made with raw fish (such as ceviche) are more likely to contain parasites or bacteria than foods made from cooked fish, so it’s important to cook fish thoroughly (at least 145°F for 15 seconds) or use commercially frozen seafood in raw dishes.”

If a parasite is present in a fish, you have several options:

  • Remove the parasite, examine the fish for others, and cook the fish, as thorough cooking kills all parasites
  • Notify the store where you bought the fish so that the store can carefully inspect remaining fish
  • Depending on the return policy of the particular store, you may wish to return or exchange the unused portion


The following seven tips are designed to help you increase your odds of enjoying your sushi while decreasing your risk of a stomach ache caused by parasites, as according to this article written by Colleen M. Story at RenegadeHealth:

  1. Saltwater fish: Saltwater fish are less likely to be infected than fresh-water fish. Choose albacore, Atlantic cod, rockfish, eel, flounder, grouper, halibut, Pacific bluefin tuna, and swordfish to raise your odds of avoiding parasites. Freshwater fish like catfish, trout, and sturgeon have a slightly higher risk of infection.
  2. Wasabi: Use your wasabi — it naturally kills parasites.
  3. What ocean? Choose fish from the Atlantic Ocean over those from the Pacific Ocean — the Pacific has a higher population and can spread more parasites.
  4. Farmed may be better: If you’re going for raw fish, choose farmed over wild-caught. Farmed fish are raised in controlled environments and rarely have parasites. (Check the source on farmed salmon—see our post for more. Some organic farmed salmon is safe, but others are full of contaminants.)
  5. Choose tuna: They are so rarely infected by parasites that the FDA doesn’t even require them to be frozen to kill parasites, though most manufacturers freeze them anyway. Tuna are fast-moving fish and are rarely in areas where parasites spread. Note, however, that they may be higher in mercury and other metals than other types of fish. Ahi and bigeye Tuna are usually the highest in mercury. Canned, chunk light is one of the lowest in mercury of all tuna types.
  6. Ask for “sashimi grade” fish: These fish go through all of the FDA measures to guarantee safety. They are inspected and found to be at least very low in parasites, and then are frozen to the point that parasites cannot survive.
  7. Ask for young fish: They have been around for less time than older fish, and will be less likely to have contracted parasites.


A response from a doctor to a concerned reader with questions yielded this reply:

Anisakiasis is a parasitic disease contracted from infected seafood which is eaten raw or marinated. This is a type of round worm which can be picked up from eating sashimi, sushi, and ceviche.

Symptoms are variable and can range from an acute syndrome with nausea and vomiting, abdominal pain or diarrhea within 12 hours of eating infected seafood to other problems which can last weeks to months. Anisakiasis can mimic other diseases, such as acute appendicitis, stomach tumors, and inflammatory bowel disease.

This author has seen one case in 14 years in which the worm migrated completely through the small bowel wall causing an acute abdomen and necessitated a laparotomy with resection of the affected segment of intestine.

In other words, the parasite should be more concerned than you if you accidentally ingest it; and you stand a better chance of being sick from bacteria than from parasites.

However, you might want to be especially careful about eating spicy tuna sushi, which was linked to a Salmonella outbreak in 20 states back in 2012 and had reportedly sickened a total of 425 people in 28 states and the District of Columbia — and 55 of those people were hospitalized, according to the Centers for Disease Control and Prevention in Atlanta.

Nakaochi Scrape — used in the preparation of some spicy tuna sushi — is “tuna backmeat that is scraped from the bones of tuna and may be used in sushi, sashimi, ceviche, and similar dishes.” This sounds eerily similar to the “pink slime” scandal where questionable parts of a cow are processed and used to create — I think this is one of the most creative euphemisms — “lean fine textured beef.” However — unlike “lean fine textured beef”, which is reportedly making a comeback due to rising beef prices — spicy tuna is not treated with ammonia or citric acid.

Know where you eat your sushi. Reputable chefs will only use sushi-grade ingredients, and no self-respecting sushi chef will use sub-par ingredients — even if they are not considered sushi-grade quality. Research reputable reviews of the restaurants to which you intend to consume sushi, and — while there is no guarantee you will get a completely truthful answer — ask the proprietors of the restaurants if they use fish “scrapings” for their sushi. If you are unusually queasy and averse to the possibility of eating the product in question, avoid eating spicy tuna sushi altogether and consume the wide variety of other kinds of sushi available — although I would have to say that I personally believe that is too extreme.

If you really want to take the proper precautions of not consuming tuna “scrapings” and you know your way around the kitchen, purchase some raw tuna at a reputable market, grind the fish yourself at home and create your own fresh spicy tuna sushi. You can customize it to your taste, and you might even save money. However, keep in mind that many freezers in homes are not cold enough to affect any parasites which might be residing in the raw fish.

As for me, I have eaten in many sushi establishments from Atlanta to Québec to Tokyo; consumed sushi at parties and events; as well as eaten sushi which was prepared and packaged in supermarkets — and I never contracted an illness, became nauseous, or even felt bad. If I have as many tapeworms in my body as Los Angeles has cars clogging its highways, I certainly do not know about it. They could be partying it up for all I care; or perhaps — more likely — there are none in my body at all…

…so go ahead and enjoy your sushi; and extra points for you if you use wasabi. However, it probably would not be a bad idea to give each piece of sushi which you are about to eat a quick inspection to ensure that no parasites are present.

Hey, Stefan — when are you going to be available to dine on sushi for lunch again at our usual restaurant?!?…

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