Is Eating Raw Fish Safe and Healthy?

raw fish

For a variety of reasons, cooking fish before eating it is more convenient than giving it raw.

The most important thing is that cooking kills germs and parasites that can make you sick.

Still, some people like the way raw fish feels and tastes better. When it’s part of sushi or sashimi, Japanese people love it the most.

But is raw fish really safe? This article assesses the potential drawbacks and advantages.

Types of Raw Fish Dishes

More and more people are eating raw fish meals. Here are a few examples:

  • Sushi: Sushi is a type of Japanese cuisine that combines cooked, vinegared rice with a variety of other ingredients, including raw fish.
  • Sashimi: Another Japanese dish is sashimi, which is thinly sliced raw meat or fish.
  • Poke: In Hawaii, poke is a traditional salad consisting of seasoned raw fish chunks mixed with vegetables.
  • Ceviche: The famous Latin American dish ceviche features lightly marinated seafood. Typically, it involves curing raw fish in lemon or lime juice.
  • Carpaccio: A popular dish in Italy, this dish consists of thinly sliced or pounded raw beef. The term may also refer to similar dishes made with other types of raw meat or fish.
  • Koi pla: Southeast Asian food Finely chopped raw fish, lime juice, fish sauce, garlic, chilies, herbs, and vegetables combine to make koi pla.
  • Soused herring: Soused herring is a popular dish in the Netherlands. The dish consists of marinated raw herring.
  • Gravlax: Nordic cuisine produces gravlax, a dish of raw salmon cured in dill, sugar, and salt. People used to eat it with mustard sauce in the past.

These meals are extremely important to the way people eat around the world.

Infections with parasites from raw fish

A parasite is an animal or plant that takes food from another living thing, called the host, but doesn’t give anything in return.

Some parasites don’t show any clear signs right away, but many of them can do a lot of damage over time.

In many tropical countries, parasitic infections in people are a big health risk. Drinking contaminated water or eating undercooked food, such as raw fish, can spread many parasitic infections.

You can lower this risk, though, by only getting raw fish from restaurants or suppliers you know and trust and that have handled and cooked it properly.

Here is a list of some of the most common parasitic diseases that people can get from eating raw or undercooked fish.

Flukes in the liver

The sickness that liver flukes cause is called opisthorchiasis. Liver flukes are classified as flatworm parasites. Most infections happen in warm parts of Asia, Africa, South America, and Eastern Europe.

Opisthorchiasis affects about 17 million people around the world, with most of them living in Southeast Asia, according to researchers.

Adult liver flukes live in sick people and other mammals and feed on blood. They could lead to a bigger liver, an infection in the bile duct, swelling in the gallbladder, gallstones, and even liver cancer.

Eating raw or improperly cooked fish appears to be the primary cause of opisthorchiasis, and unwashed hands, unclean work surfaces, and unclean cooking tools can exacerbate the condition.


People contract fish tapeworms when they consume raw or undercooked freshwater fish or sea fish that spawn in freshwater rivers. One of these is salmon.

They are the biggest parasites that are known to affect people. They can grow up to 49 feet (15 meters) long. Scientists think that up to 20 million people around the world may have caught them.

Most of the time, fish tapeworms don’t make you sick, but they can sometimes cause a sickness called diphyllobothriasis.

Most of the time, diphyllobothriasis only causes mild signs like tiredness, stomach pain, diarrhea, or constipation.

Tapeworms may also take a lot of nutrients, especially vitamin B12, from their host’s gut. This could make vitamin B12 levels low or cause a shortage.


Parasitic roundworms can cause the illness Anisakiasis. Some fish, such as salmon, spend some or all of their lives in the water, where these worms grow.

Places like Scandinavia, Japan, the Netherlands, and South America, where people frequently eat fish raw, lightly pickled, or salted, are where infections are most common.

Unlike many other parasites that fish spread, Anisakis roundworms can only survive in humans for a brief period of time.

When they attempt to burrow into the intestinal wall, they become trapped and ultimately die. This could set off a strong immune response that causes swelling, stomach pain, and throwing up.

Another thing that can happen is an immune response, even if the worms are already dead when the fish is eaten.

Another group of parasitic roundworms may cause the disease known as gnathostomiasis.

In Southeast Asia, Latin America, India, and South Africa, you can find these worms in fish, chicken, and frogs that are raw or not cooked all the way through. It is rare outside of Asia, though.

Stomach pain, vomiting, loss of hunger, and fever are the main signs. It could sometimes lead to sores, rashes, itching, and swelling on the skin.

The illness could be very bad for many organs, depending on where in the host’s body the parasitic larvae go.

Bacterial Infections

Another reason to cook fish is food poisoning. Having an upset stomach, feeling sick, throwing up, or having diarrhea are the major signs of food poisoning.

Raw fish can harbor potentially dangerous bacteria such as Listeria, Vibrio, Clostridium, and Salmonella.

According to a US study, 10% of imported raw seafood and 3% of US-grown raw seafood contained Salmonella.

But for healthy people, eating raw fish doesn’t pose much of a risk of getting sick.

People with weak immune systems are more likely to get sick, like the elderly, young children, and people living with HIV. People in these high-risk groups should stay away from fish and meat that are still raw.

Additionally, doctors frequently advise pregnant women against eating raw fish due to the risk of Listeria infection, which can kill the unborn child.

About 12 out of every 100,000 pregnant women in the US get sick right now.

Contain Higher Amounts of Pollutants

Persistent organic pollutants (POPs) are toxic chemicals produced in factories, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl esters (PBDEs).

POPs are known to build up in fish, especially farmed fish like salmon. The main cause appears to be the use of toxic fish food.

A lot of these pollutants in the body have been linked to long-term diseases like cancer and type 2 diabetes.

One study found that cooked salmon contained about 26% fewer POPs than raw salmon of the same type.

Heavy metals that are bad for your health, like mercury, are another issue. Another study found that cooked fish had 50–60% less bioaccessible mercury than raw fish. While cooking, fish pieces lose fat, which may explain this.

Cooking fish may reduce the likelihood of some contaminants entering your body, but it may not affect all of them.

Benefits of Eating Raw Fish

Eating raw fish is good for you in some ways. Firstly, raw fish lacks the harmful chemicals formed during frying or cooking. For instance, cooking fish over high heat may result in varying levels of heterocyclic amines. Observational studies have linked a high intake of heterocyclic amines to a higher chance of getting cancer.

Second, cooking fish in oil may lower the amount of good omega-3 fatty acids, such as EPA and DHA. Cooking fish, to put it simply, may make some of its nutritional value worse.

Raw fish is also good for you in ways that are unrelated to its health. It saves time not to have to cook, and enjoying raw fish dishes helps keep cultural differences alive.

How to Eat Raw Fish Without Getting Sick

If you like the way raw fish tastes and feels, there are a few things you can do to lower your risk of getting parasitic and bacterial diseases.

  • Only frozen fish is suitable for consumption: To kill bugs, freeze fish for a week at -4°F (-20°C) or for 15 hours at -31°F (-35°C). But remember that not all home freezers will get cold enough.
  • Check your fish: Many bugs are hard to see, so checking the fish before eating it may not be enough.
  • Buy from trustworthy sellers: When you buy fish, make sure you get it from restaurants or fish shops that you know will store and handle it properly.
  • Buy fish that has been kept cold: Only buy fish that has been kept cold or that is on a thick bed of ice under a cover.
  • Make sure it smells good: If the fish smells too salty or sour, don’t eat it.
  • You shouldn’t keep fresh fish for too long: If you don’t freeze it, put it on ice in the fridge and eat it within a few days.
  • Don’t leave the fish out for too long: Never leave fish out of the fridge for more than two or three hours. When it’s at room temperature, bacteria grow very fast.
  • Wash your hands: To avoid spreading germs to other foods, wash your hands after handling raw fish.
  • Clean up your kitchen and cooking equipment: To keep germs from spreading, you should also clean the work areas and tools you use in the kitchen.

While freezing doesn’t kill germs, it can slow their multiplying.

Fish that has been marinated, brined, or cold-smoked may have fewer parasites and bacteria on it, but these methods are not 100% effective at keeping you from getting sick.

The bottom line

There is a bigger chance of getting parasitic infections and food poisoning when you eat raw fish. You can, however, reduce the risk by following a few simple rules

First, make sure you only buy fish from reputable stores.

Additionally, you should have frozen the raw fish first. Freeze the fish at -4°F (-20°C) for a week to eliminate all bugs.

For two days, thawed fish should be kept on ice in the fridge and eaten.

By following these tips, you can eat raw fish at home or in public places without putting your health at great risk.

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