Doctors Warn: These 4 Foods Can Carry Parasites — But You Don’t Have to Stop Eating Them

Parasites in food sound terrifying, especially when you see close-up images of worms inside fish or seafood. Viral posts often take this fear even further, claiming that certain foods are “loaded with parasites” and that you should stop eating them immediately.

But the reality is more nuanced.

Some foods can carry parasites when they are raw or undercooked, particularly certain fish, freshwater seafood, and meats. However, that does not mean these foods are inherently dangerous or that everyone who eats them will become infected.

In many cases, proper cooking, freezing under appropriate conditions, safe food handling, and choosing products from reputable sources can dramatically reduce the risk.

Here are four categories of food that deserve extra attention when it comes to foodborne parasites.

1. Raw or Undercooked Fish

Raw fish is one of the foods most commonly associated with foodborne parasites.

Certain marine fish can carry Anisakis, a type of parasitic roundworm. Humans can become infected when they eat raw or insufficiently cooked fish containing viable larvae.

This is one reason dishes such as raw fish, ceviche, and certain types of sushi require careful sourcing and preparation.

Anisakis infection can cause symptoms such as:

• Severe abdominal pain
• Nausea
• Vomiting
• Diarrhea
• Occasionally allergic reactions

Symptoms can sometimes begin relatively soon after eating infected fish.

However, this doesn't mean you need to eliminate fish from your diet.

Cooking fish thoroughly kills parasites.

For people who choose to eat raw fish, commercial freezing processes designed for parasite control can also be important. However, simply placing fish in an ordinary home freezer should not automatically be assumed to make every fish safe for raw consumption, because household freezers and freezing times may not meet validated parasite-destruction requirements.

2. Freshwater Fish

Freshwater fish deserve particular attention because certain species can carry parasites capable of infecting humans.

Depending on the region and fish species, these can include parasites associated with liver fluke infections and other foodborne parasitic diseases.

The risk is especially relevant when freshwater fish are eaten:

Raw, lightly cooked, fermented, salted, or otherwise prepared without a reliable parasite-killing step.

Traditional dishes can be delicious, but preparation methods that don't adequately kill parasites may carry risks.

Thorough cooking is one of the simplest ways to reduce that risk.

If you regularly eat raw or undercooked freshwater fish, particularly fish caught locally rather than purchased from a regulated commercial source, it's worth understanding the parasite risks specific to your region.

3. Crab and Other Crustaceans

The crab shown in the image is another food category that can be associated with parasites when it is raw or inadequately cooked.

Certain freshwater crabs and crayfish can transmit Paragonimus, commonly known as lung flukes.

People can become infected after consuming infected crustaceans that are raw or insufficiently cooked.

Paragonimus infection can affect the lungs and may cause symptoms such as:

• Persistent cough
• Chest discomfort
• Fever
• Fatigue
• Coughing up blood in some cases

In some situations, the infection can affect other organs as well.

The important distinction is that properly cooked crab and crayfish are not equivalent to raw or undercooked crustaceans.

You don't need to panic when you see crab on your dinner plate.

The key question is:

Was it properly cooked?

4. Raw or Undercooked Pork

Pork is another food that has historically been associated with several parasites.

One well-known example is Trichinella, a parasitic roundworm that can cause trichinellosis when people eat infected meat that is raw or undercooked.

Modern commercial pork production has greatly reduced the risk in many countries, but infection remains possible, particularly with wild game or meat from less-regulated sources.

Symptoms of trichinellosis can include:

Nausea, diarrhea, abdominal discomfort, fever, muscle pain, weakness, and swelling around the eyes.

Severe infections can cause serious complications.

The safest approach is straightforward:

Cook pork and wild game thoroughly and use a food thermometer rather than relying only on the color of the meat.

Wild boar and other game animals deserve particular caution because parasite prevalence can differ substantially from that of commercially raised livestock.

Are the Worms in the Picture Really Parasites?

This is an important point when looking at viral health images.

A photograph showing a worm-like object inside fish or seafood does not, by itself, prove that it is a dangerous human parasite.

Fish can contain naturally occurring organisms, connective tissues, blood vessels, or parasites that vary by species.

Some visible parasites may be unpleasant to look at but may not be capable of infecting humans.

That's why it's risky to diagnose a parasite from a social-media photograph.

The exact species, host, geographic location, preparation method, and cooking history all matter.

You Don't Need to Stop Eating These Foods

This is perhaps the biggest misunderstanding created by the headline.

Fish, crab, pork, and other animal foods can all be part of a healthy diet.

Fish, for example, can provide:

High-quality protein, omega-3 fatty acids, vitamin D, vitamin B12, selenium, iodine, and other nutrients.

The issue isn't that these foods are inherently “dirty” or “full of worms.”

The issue is how they are sourced, handled, stored, and prepared.

In other words:

Food safety matters more than fear.

Cooking Is One of Your Best Defenses

Heat can kill many foodborne parasites.

When cooking meat or seafood, using a food thermometer is more reliable than judging doneness by appearance alone.

Different foods have different safe cooking requirements, so follow reputable food-safety guidance for the specific food you're preparing.

Avoid assuming that:

• Lemon juice kills every parasite
• Vinegar makes raw fish safe
• Salt completely eliminates parasite risk
• Alcohol “sterilizes” seafood
• Marinating automatically makes meat safe

Some traditional preparation methods may reduce certain risks, but they should not be treated as universal substitutes for proper cooking or validated freezing procedures.

What About Sushi?

Sushi is a good example of why context matters.

Commercially prepared sushi can be safe when appropriate fish are sourced and handled according to food-safety standards.

For fish intended to be eaten raw, parasite-control freezing procedures may be used depending on the species, source, and applicable regulations.

But there is a difference between professionally prepared raw fish and catching a fish yourself and assuming that freezing it overnight in your home freezer makes it safe to eat raw.

If you're preparing raw fish at home, understand the specific parasite-control requirements for that species and preparation.

Who Should Be Especially Careful?

Everyone should practice food safety, but certain people face greater consequences from foodborne infections.

Extra caution is appropriate for:

Pregnant people, young children, older adults, and people with weakened immune systems or certain chronic medical conditions.

These groups may be more vulnerable to complications from infections.

For them, avoiding raw or undercooked animal foods may be especially important depending on the specific food and medical circumstances.

What Happens If You Suspect a Parasite Infection?

Don't panic.

Many gastrointestinal symptoms after eating are caused by bacteria, viruses, food intolerance, or other conditions rather than parasites.

However, if you develop persistent symptoms after eating potentially contaminated food—especially prolonged abdominal pain, diarrhea, fever, unexplained weight loss, persistent cough, or other unusual symptoms—talk with a healthcare professional.

Tell them what you ate, when you ate it, whether it was raw or undercooked, and whether the food came from a restaurant, store, or your own catch.

That information can help guide testing and treatment.

The Bottom Line

Yes, certain foods can carry parasites.

Raw or undercooked fish, freshwater fish, freshwater crustaceans such as some crab and crayfish, and undercooked pork or wild game are examples where parasite exposure can be a concern.

But the viral message that these foods are simply “loaded with parasites” and must be avoided is misleading.

The real lesson is much more practical: