Yes, sashimi can contain parasites. Raw fish naturally harbors several types of parasitic organisms, and eating it without proper preparation carries a real risk of infection. The most common culprit is a roundworm called Anisakis simplex, which accounts for roughly 88% of parasitic infections from raw fish. That said, the sashimi served at reputable restaurants has almost always been frozen to temperatures that kill parasites before it ever reaches your plate.
Which Parasites Live in Raw Fish
The parasite you’re most likely to encounter in sashimi is Anisakis, a small roundworm (about 2 cm long) that lives in the guts and flesh of marine fish and squid. A related roundworm, Pseudoterranova, is the second most common. Both belong to the same family and cause a condition called anisakiasis when swallowed alive.
Fish tapeworm (Diphyllobothrium) is another concern, particularly with salmon and other fish that spend part of their life in freshwater. Unlike the roundworms, tapeworm infections can become chronic, sometimes lasting months and causing vitamin B12 deficiency. Several types of liver and intestinal flukes also show up in raw fish, though these are more common in parts of Asia and the Middle East. Raw squid and eel carry Anisakis larvae as well.
How Often People Actually Get Infected
Japan, where raw fish consumption is highest, sees the most cases by far. A 2022 study using health insurance data estimated roughly 19,700 cases of anisakiasis per year in Japan, a number more than 40 times higher than what official food poisoning statistics had been reporting. Spain, where marinated raw anchovies are popular, sees an estimated 7,700 to 8,320 annual cases. In the United States, infections are much rarer, likely because of stricter freezing practices in the commercial supply chain.
Most infections involve larvae found in the stomach, where they burrow into the lining and cause intense pain within hours of eating contaminated fish. A smaller number of larvae make it into the intestines, where symptoms can take days to appear and are harder to diagnose.
What an Infection Feels Like
Anisakiasis typically hits fast. Within one to two hours of eating infected fish, you may experience sudden, severe stomach pain, nausea, and vomiting. Some people describe it as the worst abdominal pain they’ve ever had. If the larvae reach the intestines instead, symptoms show up later (sometimes up to two weeks) and can include diarrhea and cramping that mimics appendicitis or a bowel obstruction.
In some cases, the body mounts an allergic response to the larvae even after they die. This can cause hives and, rarely, a serious allergic reaction. Tapeworm infections, by contrast, are often mild or completely silent for weeks. The first sign might be abdominal discomfort, diarrhea, or fatigue from gradual B12 depletion.
The good news: most roundworm infections resolve on their own because the larvae can’t survive long in the human body. When treatment is needed, a doctor can usually pull the worm out with an endoscope. Surgery is reserved for rare complications like bowel obstruction.
How Freezing Makes Sashimi Safe
Freezing is the primary safety measure that separates a dangerous piece of raw fish from a safe one. The FDA recommends one of three freezing protocols for any fish intended to be eaten raw:
- Standard freezing: held at -4°F (-20°C) or below for 7 days
- Blast freezing, option one: frozen to -31°F (-35°C) until solid, then held at that temperature for 15 hours
- Blast freezing, option two: frozen to -31°F (-35°C) until solid, then stored at -4°F (-20°C) for 24 hours
All three methods reliably kill every parasite species found in fish. The EU has similar requirements, mandating that raw fish products be frozen to at least -20°C for 24 hours or -35°C for 15 hours before sale. Under the FDA Food Code, restaurants serving raw fish must either source it from a supplier that has already performed this freezing step or freeze it on-site and keep records proving they did so.
Why Your Home Freezer May Not Be Enough
If you’re buying fish to prepare sashimi at home, your kitchen freezer is probably not cold enough. Most household freezers operate around -18°C (0°F), which falls short of the -20°C (-4°F) minimum that regulations require. Research has shown that some Anisakis larvae survive freezing at -15°C and -18°C, temperatures that are well within the range of many domestic freezers. Home freezers also cool food more slowly than commercial blast freezers, giving parasites more time at survivable temperatures.
This means buying a whole fish from a market and freezing it yourself is not a reliable way to make it safe for raw consumption. If you want to make sashimi at home, look for fish that has already been commercially frozen to the proper specifications. Some fishmongers and specialty markets sell fish specifically labeled for raw consumption that has undergone this process.
What “Sushi Grade” Actually Means
There is no legal definition for the terms “sushi grade” or “sashimi grade” in the United States. No federal agency regulates or certifies those labels. They are marketing terms used by fish sellers to indicate that, in their judgment, the fish is high enough quality to eat raw. In practice, reputable suppliers use these labels on fish that has been frozen according to FDA guidelines, but nothing legally requires them to do so.
The FDA Food Code does make one notable exception to its freezing requirements: certain large species of tuna (such as bluefin, yellowfin, and bigeye) are exempt. These deep-ocean fish have a lower parasite risk than most other species, and freezing can degrade the texture of tuna more noticeably. Farmed fish fed parasite-free feed, certain types of shellfish, and fish eggs are also exempt.
Which Fish Carry More Risk
Salmon is one of the higher-risk species for parasites in sashimi because it spends part of its life in freshwater, where it picks up both roundworm larvae and tapeworm larvae. Wild-caught Pacific salmon is especially prone to Anisakis. This is why virtually all salmon served raw in restaurants has been commercially frozen first, even in Japan.
Squid also carries Anisakis larvae and has been linked to documented infections. Mackerel, herring, cod, and anchovies are other commonly infected species. Tuna, particularly the large open-ocean species, carries significantly lower parasite risk, which is why it’s one of the few fish that regulations allow to be served raw without prior freezing. Farmed fish raised on processed feed in controlled environments also tend to have minimal parasite exposure, though the risk is not zero.
The bottom line: raw fish does carry parasites in the wild, but the commercial freezing process used by restaurants and reputable suppliers is extremely effective at eliminating them. Your biggest variable is where you’re eating and how the fish was handled before it reached you.