Everything You Need To Know About Raw Fish

If you enjoy sushi, sashimi, or any other dish containing raw fish, it’s essential to be aware of the potential dangers.

While eating raw fish may seem like a risky proposition, there are ways to minimize the risk and still enjoy your favorite dishes.

Potential Risks From Raw Fish

The two main types of infection that may result from eating raw fish are bacterial infections and parasitic infections.

Bacterial Infections

Harmful bacteria that have been found in raw fish include:

  • E. Coli
  • Staphylococcus aureus
  • Salmonella spp.
  • Listeria spp.
  • Vibrio spp.
  • Clostridium spp.

These infections are not too common and are typically due to poor food handling practices. Still, people with weaker immune systems or are otherwise at high-risk (older adults, young children, people living with HIV, pregnant women) are advised to avoid raw fish.

Symptoms of bacterial food poisoning include:

  • upset stomach
  • nausea
  • diarrhea
  • vomiting

If you experience bloody diarrhea, high fever (102+°F), or frequent vomiting after eating raw fish, seek medical attention as soon as possible.

Parasitic Infections

Parasites are even less common than bacterial or viral infections but still can happen, especially in areas where raw foods are a big part of the common cuisine.

The most common types of parasites that can be found in raw fish:

  • roundworms
  • tapeworms
  • liver flukes

Sometimes, a parasitic infection may not cause noticeable symptoms right away, but it can grow and lead to more severe problems over time.

For example, tapeworm infections often present with only mild fatigue and discomfort, but the tapeworm could steal vital nutrients from your body and lead to a vitamin deficiency.

Diseases associated with roundworm infections can be more severe, causing:

  • stomach pain,
  • vomiting
  • appetite loss
  • fever
  • swelling
  • itching
  • rashes or skin lesions

If you experience any of these symptoms after eating raw fish or are concerned about a possible infection, see a doctor immediately.

Toxic Pollutants

Some fish may also contain harmful toxins (persistent organic pollutants) such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl esters (PBDEs).

High intake of these pollutants may increase your risk of chronic diseases such as cancer and type 2 diabetes.

Cooking appears to reduce the presence of these toxins, though it may not eliminate them completely.

Eating Raw Fish Safely

With all this in mind, there are still ways you can eat raw fish while minimizing the risk of infection.

  • Buy fish from a reputable source.
  • Only eat fish that has been frozen (-4°F for a week will kill parasites, but be aware that household freezers may not be cold enough).
  • Inspect fish for unusual color, smell, or texture.
  • Even on ice or refrigerated, fresh fish only stays fresh for a few days. Generally, the sooner you can eat it, the better.
  • Don’t leave it out of the refrigerator for more than an hour. At room temperature, bacteria can multiply quickly.
  • Avoid cross-contamination. Use separate cutting boards, plates, and utensils for raw fish and other foods.
  • Wash your hands thoroughly with soap and water before and after handling raw fish.

When in doubt, throw it out. If you’re not sure if the fish is fresh or if it has been properly handled, don’t take the risk.