Doesn't Shellfish Have a Ton of Cholesterol?

Actually, no. Shellfish's cholesterol level is not as health threatening as once believed.

There are a few reasons why shellfish may have a bad reputation when it comes to cholesterol. First, shellfish contain a variety of sterols, a group of chemical compounds that includes cholesterol. Previously, scientists could not distinguish among the different sterols and all were labeled as cholesterol. As a result, the amount of cholesterol in shellfish was overestimated. In reality, shellfish contain less cholesterol than meat or poultry.

Not Much Fat, Though

Bad Company

The company that shellfish keep, however, can be a problem. Shellfish are often served with melted butter or a mayonnaise-based tartar sauce. And shellfish are frequently battered and deep fried. Both actions can turn a low-fat dish into a high-fat bomb by increasing the total fat and the saturated fat. Instead, try steaming shellfish and serving with lemon and spices.

What Makes a Fish a Shellfish?

It is as simple as it sounds—shellfish are sea creatures that have a shell of some kind. There are two basic categories:

Crustaceans—They have elongated bodies with jointed, soft shell. These include crabs, crayfish, lobster, and shrimp.

Mollusks—These have soft bodies covered by a shell of one or more pieces. Mollusks are divided into three categories:

• Univalves—a single shell and a single muscle; includes abalone and snail
• Bivalves—two shells hinged together by a strong muscle; includes clam, scallop, mussel, and oyster
• Cephalopods—tentacles attached to the head and an ink sac; includes octopus and squid

Shellfish Allergies

Shellfish are one of the most common allergens, and the allergy is rarely outgrown. Reactions usually appear within two hours after ingesting shellfish, inhaling cooking vapors, or handling shellfish, but can be delayed as long as 24 hours. Common symptoms include:

Shellfish Poisoning

What About Mercury?

Considerable concern has grown about mercury levels in fish. This is a problem with some shellfish too. Although shellfish do not usually approach the mercury levels of the worst fish offenders (such as swordfish and shark), lobster has as much mercury as canned white tuna, and scallops and crab have about a sixth as much. Mussels vary in mercury content depending on their origin. Shrimp and oysters have little to no mercury content.

Guidelines for Cooking Shellfish

Seafood should be cooked so that the internal temperature is 145°F (63ºC). You will also know when seafood is cooked by doing the following:

• Fish—Cut through the side of the fish and open it up to expose the flesh. The inside should be opaque and separate easily.
• Shrimp and lobster—When cooked, the flesh should be pearly-opaque.
• Scallops—The flesh should look milky white/opaque and firm.
• Clams, mussels, oysters—When the shells open, they are done. Throw out any ones that do not open.

Nutritional Info

g = grams; mg = milligrams