Dangers of Eating Raw Fish

​Have you ever suspected that something is wrong with your raw seafood?  Do you know that raw fish is a source of bacteria, and it is essential to know these dangers, especially when indulging in sushi?

Dangers of Eating Raw Fish
By Pierre Mouchette | Bits-n-Pieces

The Dangers of Eating Raw Fish
While dishes such as sushi and ceviche have been served and enjoyed for generations, you should be aware of several scary things potentially hiding in them before you indulge.  Raw fish can become infected with various types of bacteria and worms or have a higher concentration of dangerous chemicals and microplastics.
The following are the most common bacteria and infections that raw fish tend to harbor:
E. Coli.  A strain of bacteria that could be hiding in raw fish.  Although most are harmless and cause mild symptoms of fatigue, diarrhea, and abdominal cramps, some strains of the bacteria can cause kidney failure and death.
Listeria.  A bacteria strain that can be found in raw seafood and fish.  It is most likely to infect individuals with weak or developing immune systems.  These include children, pregnant women, and the elderly.  Symptoms range from flu-like symptoms to loss of balance and convulsions.
Salmonella.  Raw fish can contain harmful bacteria, including salmonella, which can cause diarrhea, cramps, vomiting, headache, and fever.  Salmonella is the classic “food poisoning” bacteria, as it is one of the most common bacterial infections that causes the preceding symptoms.
Vibrio vulnificus.  It is an aggressive bacteria found in raw seafood (particularly oysters) and is the leading cause of death related to seafood consumption in the U.S.  Most infected individuals develop sepsis and severe cellulitis.  Researchers state that the fatality rate per case is between 30 and 40 percent, even with quick diagnosis and aggressive therapy. 
Liver Fluke.  Are a group of parasitic flatworms that reside in infected animals' livers.  Consuming raw seafood with liver flukes can lead to opisthorchiasis, which causes bile duct infections, gallbladder inflammation, gallstones, and liver cancer.  Globally, 17 million people suffer from opisthorchiasis, primarily due to consuming raw fish and unclean kitchen surfaces.
Roundworms.  These are parasites found in freshwater and some saltwater fish.  While they cannot live in humans for a long time, they can cause an immune response when they attempt to attach themselves to the intestinal wall, causing inflammation, pain, and vomiting.
Tapeworms.  These worms infect seafood breeds that spawn in freshwater, like salmon.  They can reach up to 49 feet and cause diphyllobothriasis, resulting in fatigue, diarrhea, or constipation.  The majority of the time, there are no symptoms of tapeworms.
Mercury.  All fish today contain some toxic mercury, with larger fish such as tuna having higher levels.  Research studies show that mercury levels can be up to 60 percent lower in cooked fish than in raw fish.  Mercury is highly toxic and accumulative (it builds up in the body over time), causing problems such as irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and even death.
Pollutants.  Farmed fish, in particular, will likely accumulate toxic pollutants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl esters (PBDEs).  These pollutants have been shown to cause various diseases, including cancer.  Cooking seafood reduces the risk of ingesting these toxins.
 
How to Detect a Bad Fish.
Of course, if you are an avid sushi or sashimi-lover, this is not to say you should never touch your favorite dish again.  Understanding the dangers of raw fish consumption is essential to recognize symptoms if you become infected and be informed enough to make good seafood choices.
Identifying an unsafe fish before you eat it is most important.  While you should always buy frozen fish if you are going to eat it raw, there are some clues to look for to help identify harmful fish in markets and grocery stores.

• Smell - a telltale indicator of harmful fish.  Keep walking if you smell ammonia, a “fishy” smell, or anything gag-inducing.  Fresh fish should always smell like the ocean and nothing more.
  
  
• Skin - the flesh of an unfrozen fish should be firm and spring back when you touch it.
  
  
• Eyes and Gills - if you purchase a whole fish, the eyes should be clear and not red or bulging.  The gills should also be red; any other color signifies aging.
  
  
• Slime - fish that has or is about to go bad will have a coating of slimy moisture over it and feel slippery when touched.

 
If you are going raw, buy cold and wild.
Consuming wild fish can reduce exposure to chemicals like mercury, so avoid farmed fish whenever possible.  Buy fish that is or has been frozen because the freezing process effectively kills parasites and worms.  If you are uncertain if a fish was previously frozen, place it in your freezer at home for at least seven days before consuming it, and ensure to thaw it slowly (for quality).  The one exception is pelagic fish like tuna (pelagic means they do not live close to the bottom or near the shore and are not bottom feeders).  Pelagic fish are most often consumed raw (without freezing first) because they do not possess parasites that are dangerous to humans.