Although studies by industry groups and organisations like the American National Academy of Sciences conclude that "most seafood available is wholesome and unlikely to cause illness," eating raw food - any kind - is considerably riskier than eating cooked foods.
What the experts have to say
Doris Hicks, a seafood specialist, says there are legitimate concerns about the potential health hazards of favourites like raw clams, oysters and mussels.
While there are no guarantees, a healthy adult should be able to eat carefully prepared raw seafood, experts like Hicks say. But it's riskier for those with many medical conditions ranging from diabetes to liver disease.
"Most common food-borne illnesses are caused by a combination of bacteria occurring naturally in the environment and food-handling errors made in commercial settings or at home," Hicks says.
She adds that you need to be careful with raw delicacies like sushi (pieces of raw fish with rice and other ingredients), sashimi (chunks of raw fish) and seviche (fish and spices marinated in lime juice). "Marinating seafood will not destroy either parasites or bacteria," Hicks says - it's no safer than eating the fish raw.
Pollution's the problem
The big problem with raw shellfish, the US Food and Drug Administration says, is bacterial or viral contamination caused by pollution. While shellfish raised in aquafarms or carefully monitored open waters are generally safe, a contaminated clam, mussel or oyster can lay low even a vigorous adult.
Symptoms, though not life-threatening for the healthy, can range from mild intestinal disorders to acute gastroenteritis, a severe inflammation of the lining of the stomach and intestines characterised by nausea, diarrhoea and pain.
Severe consequences for some
But contaminated raw seafood can have severe and potentially fatal consequences for some. Those at high risk include people with liver disorders, iron imbalances, diabetes, gastrointestinal disorders, or weakened immune systems caused by diseases like Aids and cancer.
Heavy drinkers should also be cautious. They risk serious consequences if infected with the bacterium Vibrio vulnificus, which occurs naturally in marine waters and is often found in raw seafood. People with liver disease, which is common among alcoholics, are 200 times more likely to die from this bacterium than those without liver disease, the agency says.
Hicks also says contaminated raw seafood is a potential danger for the very young and very old, as well as pregnant women. "The biggest factor is the state of your health," she says. - (HealthScoutNews)