Fish and shellfish are usually considered healthier alternatives to red meats, but they still have their caveats. For instance, shellfish in particular contain varying amounts of cholesterol. Although shellfish has been a no-no for people who're watching their cholesterol intake, you might be surprised to learn that shellfish doesn't contain as much cholesterol as you think. If you're concerned about your cholesterol, fish or shellfish intake, consult your doctor or a registered dietitian.
Types
Crab, lobsters, oysters, shrimp, crayfish, abalones, clams, mussels and scallops are among the seafood in the category of shellfish, says the University of Pittsburgh Medical Center. Unlike shellfish, other types of fish don't typically contain much cholesterol, according to MayoClinic.com. In fact, most fatty cold-water fish contain no cholesterol and "healthy" types of fats instead. These types of fish include salmon, herring and mackerel, among others, MayoClinic.com notes.
Misconceptions
Although many people believe that all shellfish contain large amounts of cholesterol, this isn't true, says the University of Pittsburgh Medical Center. Shellfish and seafood do contain dietary cholesterol, which is considered a "harmful" type of fat, MayoClinic.com notes. But cholesterol is only one small component of the similar chemical compounds called sterols in shellfish. Shellfish actually contain smaller amounts of cholesterol than chicken and meats.
Amounts
Among the different types of shellfish, lobster and Dungeness crab contain the largest amount of cholesterol, with about 142.5 milligrams of cholesterol in each lobster and 96 milligrams in each whole crab, says the University of Pittsburgh Medical Center. Abalone and Alaskan king crab are next in line, with about 72 milligrams of cholesterol in 3 ounces of abalone or one crab leg. About 1 ounce of squid contains 66 milligrams of cholesterol, four large shrimp have 42.5 milligrams of cholesterol, 20 small clams have 34 milligrams, eight pieces of crayfish have 29 milligrams, one medium-sized Pacific oyster has 25 milligrams and six medium-sized Eastern oysters have 21 milligrams. Scallops and mussels are among the shellfish that have the lowest cholesterol content. The general recommended daily intake of dietary cholesterol is no more than 300 milligrams per day, MayoClinic.com notes.
Significance
Although lobster and oysters contain small amounts, shellfish in general have no saturated fat, according to the University of Pittsburgh Medical Center. Shellfish are also fairly low in fat in general and in calories, while providing rich sources of protein and potassium. Meanwhile, most other types of fish are considered healthier alternatives to meats and poultry, providing polyunsaturated fats known as omega-3 fatty acids. Omega-3s are "healthy" fats found in the highest amounts in cold-water fatty fish like salmon, herring and mackerel, MayoClinic.com says. Also found in sardines, black cod, albacore tuna and anchovies, omega-3 fatty acids are essential to your overall health, states the University of Michigan Health System. In fact, the omega-3s found in fish may help in treating a wide variety of medical conditions, particularly arthritis, Crohn's disease, cardiovascular diseases and mental-health problems.
Warning
The real danger in eating shellfish is not so much the cholesterol content, but instead may be the potential for an allergic reaction. In fact, shellfish are the most common food allergies, notes the University of Pittsburgh Medical Center. Some people are so extremely sensitive to shellfish that they can have a severe allergic reaction from just handling shellfish or breathing in the steam from cooking them. You can also get shellfish poisoning, which occurs due to a toxin that the shellfish ingested along with plankton, and this most commonly happens from eating mussels and clams. Mercury is a concern in most fish, including shellfish. Also, keep in mind that even fish rich in omega-3s that contain no saturated fat or cholesterol can still harm your overall health when you eat excessive amounts, MayoClinic.com warns. All types of fats can provide large amounts of calories.
