There are several practical reasons people cook fish before eating it, rather than simply serving it raw. Most importantly, cooking kills bacteria and parasites that can cause disease. Nevertheless, some people prefer the texture and taste of raw fish. It is especially popular in Japan as part of dishes like sushi and sashimi. But how safe is raw fish?
These are 5 reasons you must never eat raw fish.
Parasitic Infections from Raw Fish
A parasite is a plant or animal that feeds off another living organism, known as the host, without offering any benefits in return. While some parasites do not cause any obvious acute symptoms, many may cause serious harm over the long term.
Parasitic infections in humans are a major health problem in many tropical countries. Many of them are transmitted by infected drinking water or improperly cooked food, including raw fish.
However, you can minimize this risk by buying raw fish from trusted restaurants or suppliers that have properly handled and prepared it.
Below is an overview of some of the main parasitic diseases that can be transmitted to humans after eating raw or undercooked fish.
Liver flukes are a family of parasitic flatworms that cause a disease known as opisthorchiasis. Infections are most common in tropical regions of Asia, Africa, South America and Eastern Europe. Researchers estimate that around 17 million people worldwide, most in Southeast Asia, are affected by opisthorchiasis.
Adult liver flukes reside in the livers of infected humans and other mammals, where they feed on blood. They may cause an enlarged liver, bile duct infection, gallbladder inflammation, gallstones and liver cancer.
The main cause of opisthorchiasis seems to be consuming raw or improperly cooked fish. Unwashed hands and dirty food preparation surfaces and kitchen utensils also play a role.
Salmon Sushi NigiriFish tapeworms are transmitted to people who eat raw or undercooked freshwater fish or sea fish that spawn in freshwater rivers. This includes salmon.
They are the largest parasite known to infect humans, reaching a length of up to 49 feet (15 meters). Scientists estimate that up to 20 million people may be infected worldwide. While fish tapeworms often don’t cause symptoms, they may cause a disease known as diphyllobothriasis.
The symptoms of diphyllobothriasis are usually mild and include fatigue, stomach discomfort, diarrhea or constipation.
Tapeworms may also steal substantial amounts of nutrients from the host’s gut, especially vitamin B12. This may contribute to low vitamin B12 levels or deficiency.