Hooked on Seafood: Seafood Safety

by Food and Drug Administration (FDA)

What food is nutritious, wholesome, tender, easy to digest, and yet subject to a bad press?

The answer: seafood.

Yes, despite its growing popularity in a country in which counting cholesterol has become almost as important as counting calories, seafood has often been pictured in the media as unsafe. Last year, for example, editorial writers for the New York Times, Washington Post, Atlanta Constitution, and the Dallas Morning News all quoted statistics claiming that eating fish was 25 times more likely to make you ill than dining on beef and 16 times more likely than downing poultry or pork. Both CBS TV's "This Morning" program and TV station WABC in New York City repeated those statistics in features on fish safety.

The editorial writers and the TV producers also called for new legislation to provide more government inspection of fish so that we'd be better able to keep down our seafood.

All of which caused then Acting FDA Commissioner James S. Benson to tell the New York Times in a letter to the editor: "You have been severely misled."

Supporting Benson was a report last January from the National Academy of Sciences. Completing a two-year study of seafood safety, the academy concluded: "Most seafoods available to the U.S. public are wholesome and unlikely to cause illness in the consumer."

The statistics used by the editorial writers applied to "outbreaks" of illnesses reported to the national Centers for Disease Control in Atlanta, Ga., the federal agency responsible for collecting and analyzing health statistics. (An outbreak is two or more illnesses linked to a common source.) The news people failed to pick up the distinction between outbreaks and illnesses, and failed to appreciate that CDC only tabulated those incidents reported voluntarily by state and local health authorities. These authorities tend to report only major incidents, such as outbreaks involving two or more people.

To get a truer picture of the safety of seafood, FDA's Center for Food Safety and Applied Nutrition, in cooperation with CDC, did a risk assessment study. It showed one illness per 2 million servings for seafood when raw or partially cooked molluscan shellfish (principally mussels, clams and oysters) were excluded from the calculations. (In comparison, the risk assessment for chicken is about one illness for every 25,000 servings.)

Beware Raw Mollusks

Now add raw mollusks to the statistical stew and, as Hamlet said: "Ay, there's the rub." According to the FDA risk assessment, the chance of illness for seafood overall with the raw shellfish jumps to something like one in 250,000 servings. That's still 10 times safer than eating chicken, but the agency figures that those raw oysters, clams and mussels — so savored by gourmets — account for a whopping 85 percent of all the illnesses caused by eating seafood.

Mollusks are troublemakers because they cannot move and have to feed by filtering water through their shells, pulling out nutrients in the process. In so doing, they also pick up and store harmful bacteria and viruses that can cause a string of illnesses. When people eat these pathogen-packed shellfish raw they ingest the viruses and bacteria.

Or, as Anthony Guarino, director of FDA's fishery research branch on Dauphin Island, Ala., asks: "What other animal do we eat, digestive tract and all, without cooking it first?"

These mollusks have long been consumed raw by humans, and no doubt they have made people ill throughout history. However, the threat they pose today may be greater because of increased pollution of the waters in which they live. Mollusks are usually found in estuaries, which is where rivers and seas meet. And estuaries these days are more likely to be closer to cities and thus more apt to be polluted than offshore waters.

FDA's risk assessment study concluded that one out of every 2,000 servings of raw mollusks is likely to make someone ill. For that reason, these shelled creatures could stand a little more press attention. Not enough people realize the danger in eating them uncooked, particularly when they are taken from warmer waters or held and shipped at warmer temperatures, above 38 degrees Fahrenheit. The warmer the temperature, the quicker the bacteria multiply.

Two states — Louisiana and California — now require warning notices about eating raw oysters at places where they are sold. In Louisiana the following notice is required:

WARNING: CONSUMPTION OF RAW OYSTERS CAN CAUSE SERIOUS ILLNESS IN PERSONS WITH LIVER, STOMACH, BLOOD OR IMMUNE SYSTEM DISORDERS. FOR MORE INFORMATION, CONSULT YOUR PHYSICIAN.

A similar notice is required on the tags of sacks or containers of unshucked oysters. The California warning language is much the same. That state specifies that retail establishments must display the notice in signs, menu warnings, table tents, or "other visible warnings at point of sale ...."

Oysters taken from the Gulf of Mexico, particularly from March through October, may contain a naturally occurring pathogen called Vibrio vulnificus, which is particularly pernicious to persons with liver disease, such as heavy drinkers. Cancer patients, people with iron metabolism disorders, and those with weakened immune systems (such as AIDS victims) may also be vulnerable. The risks are high. The fatality rate for at-risk individuals who become infected is more than 50 percent, with death usually occurring within two days.

While raw or undercooked shellfish continues to pose problems, the fact that, overall, seafood is a safe and nutritious part of the diet means that it's likely Americans will continue to put more seafood on their forks in the coming years. Indeed, the National Fisheries Institute, a trade organization, has set a goal of 20 pounds per citizen by the year 2000. Seafood consumption in 1989 was figured at 15.9 pounds per person, not including recreationally caught fish (which adds another 3 to 4 pounds per person). That was an increase in consumption of commercially caught fish of 25 percent since 1980. These increases occurred while beef and pork consumption declined (poultry eating also gained). All of which probably reflects health concerns of consumers.

About the Author

www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.