Nutritional Value of Scallops

Whether you are a big fan of the shelled "fish" or new to the tasty treat, scallops' nutrition may surprise you. Breaded and deep fried, steamed or served ceviche style, these morsels from the sea pack a big protein punch with a hint of healthy fats.

According to the U.S. National Oceanic and Atmospheric Administration Fisheries department, scallops are bivalve creatures like clams and oysters with two shells held together by an abductor muscle, the part commonly eaten in the United States.

There are many benefits of scallops as not only a nutritious but also environmentally-conscious seafood because they are not at-risk for overfishing like many other species.

There are more than 10,000 identified species of bivalve, and they populate areas of both fresh and saltwater, all over the world. Bivalves have been vital to humans throughout history.

The healthy fats and protein in scallops have been important in the human diet. Scallop and other bivalve shells have also been used as decoration for bodies and homes and even as currency, according to a paper by Paul Bunje at the University of California Museum of Paleontology at Berkeley.

Because bivalves filter the water around them, they are impacted by chemicals or waterborne microorganisms like bacteria or viruses that could cause illness, says the U.S. Environmental Protection Agency. You should check your state, territory or tribal advisories for any recommendations on seafood limitations or source bodies of water to avoid.

Read more: Which Fish Has the Highest and Lowest Mercury Levels?

Scallops are a good source of protein as well as healthy fats like omega-3 fatty acids. Bivalves also get a small percentage of their calories from carbohydrates, based on nutritional data from the U.S. Food and Drug Administration (FDA).

Six large or 14 small scallops, approximately 125 grams according to the U.S. Department of Agriculture (USDA), contains 140 calories and a number of other macro and micronutrients, including:

• 25 grams of protein
• 1 gram of fat
• 6 grams of carbohydrates
• 14 percent of the recommended daily amount of iron

Read more: Here's What Serving Sizes of Meat and Seafood Actually Look Like

Steam or bake scallops until opaque milky white and firm to the touch, according to the U.S. Department of Health Dietary Guidelines for Americans. Eat scallops steamed, rather than breaded and fried, to keep the healthy fats high and the sodium and saturated fats low.

Scallops could be an issue for some older men, says Dr. Helen Delichatsios, assistant professor of medicine at Harvard Medical school, on the Harvard Health blog.

Shellfish like lobster, shrimp, crab, scallops, mussels, clams, squid or octopus is often prepared with a great deal of sodium, which can be a health concern for many. Even without added salt, many types of "fish without fins" have high levels of sodium, potassium and other substances, like purines which can trigger gout attacks.

The Dietary Guidelines for Americans recommends eating a wide variety of protein sources, including at least 225 grams (approximately 8 ounces) of seafood each week. Aim for an average consumption of 250 milligrams per day of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two types of fish-derived omega-3 fatty acids.

This dietary guideline in particular is associated with reduced cardiac deaths among healthy adults and improved infant health outcomes when followed during pregnancy or breastfeeding. Pregnant people should eat 225 to 340 grams of seafood (8 to 12 ounces) from a variety of sources high in EPA and DHA, while low in contaminants like methyl mercury.

Read more: O-mazing Omega: The Benefits of Omega-3, -6, and -9 Fish Oils

While scallops' nutrition profile makes them an excellent source of fatty acids, check with your doctor and watch fishing advisories for information about mercury and other contaminants. Low-mercury alternatives to more risky bivalves include anchovies, herring, salmon, sardines, shad and trout. Enjoy a wide variety of seafood with most meals including low-mercury options.

According to a January 2012 literature review in Advances in Nutrition, EPA and DHA are vital to a number of health processes, including fetal development, cardiovascular function, the inflammatory process, cognition and healthy aging. In addition to marine animals, these fatty acids can be found in seaweed and other aquatic plants. There are few other vegetarian sources of EPA and DHA.

While land animals and plants have their own fatty acid, α-linolenic acid (ALA), is present in flax and other nuts and seeds. Advances in Nutrition reports that it has not been shown in studies to have the same health benefits as EPA and DHA in long-term studies. The body can turn some ALA into EPA and DHA, but only a very small percent, making marine sources vital.

A low intake of EPA and DHA compared to saturated fats in American diets, says Advances in Nutrition, "is thought to be associated with increased inflammatory processes as well as poor fetal development, general cardiovascular health, and risk of the development of Alzheimer's disease." Most people do not meet the recommended daily intake of these fatty acids.

Your scallops' nutrition benefits go beyond their fatty acids. That 125 gram serving of scallops doesn't just contain half a day's worth of protein! In those six large scallops you will also find, according to the USDA:

• 46.3 milligrams of magnesium, 11 percent of the recommended daily value (DV)
• 532.5 milligrams of phosphorus, 43 percent of the DV
• 1.9 milligrams of zinc, 18 percent of the DV
• 27.1 micrograms of selenium, 49 percent of the DV
• 2.7 micrograms of vitamin B12, 112 percent of the DV
• 128.4 milligrams of choline, 25 percent of the DV
• Trace amounts of calcium, iron, potassium, copper and manganese
• Trace amounts of vitamins B1, B2, B3, B5, B6, B9 and retinol

Each of these vitamins and minerals play a vital role in your body's physiological processes. According to the U.S. National Library of Medicine, magnesium is necessary for the functioning of your nerves and muscles, including your heart, as well as your immune system and bone strength.

Phosphorus is also important for the heart and other muscles, as well as in the maintenance of bones and teeth, kidney function and nerve signaling. Zinc is vital for making energy and new cells, while selenium is used to make certain proteins which help prevent cell damage from everything from cancer to heavy metals.

The B vitamins are required for a host of the body's everyday needs. Vitamin B12 in particular is necessary for the production of red blood cells to central nervous system functioning. The brain relies on choline for its normal function. Scallops, as a source of these vital nutrients, can be a good seafood choice in a healthy, balanced diet.