Clams come in many types, but the biggest distinction is between hardshell clams and softshell clams. If you are buying live clams, look for hardshell clams with closed shells or shells that close when you touch them; a live softshell clam should move when you touch its body. You can keep live clams in the refrigerator for up to two days and shucked clams for up to four days.
A 3-ounce serving of clams contains 126 calories, 43 percent of the daily value of protein and sodium, 19 percent of the DV of cholesterol, 3 percent of the DV of fat, 1 percent of the DV of carbohydrates, a negligible amount of saturated fat and no fiber.
Protein constitutes 69 percent of clams' calories. During metabolism, the body breaks down proteins into amino acids. Amino acids are integral to manufacturing, repairing and maintaining cells and to fetal and childhood growth and development. The body produces many amino acids, but one type, essential amino acids, are not produced by the body and must be eaten. Clams are a rich source of essential amino acids.
Omega-3 Fatty Acids
Clams are not a significant source of fat, but they do contain certain types of polyunsaturated fats known as omega-3 fatty acids, or fish oils. Omega-3 fatty acids are essential fats the body can't produce, so the only way to get them is to eat them. Omega-3 fatty acids help reduce inflammation and reduce the risks of heart disease, certain types of cancers and arthritis. They may also play a role in cognitive and behavioral health. If a pregnant or lactating mother doesn't consume enough fatty acids, her child may develop an essential fat deficiency, which can lead to vision and nerve damage.
A 3-ounce serving of clams provides 4,123 percent of the adult recommended dietary allowance for vitamin B-12 for both men and women. Vitamin B-12 is integral to red blood cell formation, neurological health and DNA synthesis. It may also play a role in reducing the risks of coronary artery disease, dementia and age-related cognitive decline. A serving of clams supplies 165 percent of the adult male RDA for iron and 132 percent of the RDA for women. Iron helps take oxygen from the lungs into the bloodstream and finally to cells, and also helps with cell growth and differentiation. The Office of Dietary Supplements reports that up to 80 percent of the world's population may suffer from mild to severe iron deficiency. Clams also offer 116 percent of the RDA for selenium for both men and women, a mineral that combines with protein to form antioxidant selenoproteins. Selenoproteins help prevent cellular damage from free radicals that can lead to cancer and coronary artery disease.
A combination of warm ocean surface temperatures, high nutrient content, low salinity and calm waters can produce a phenomenon known as "red tides." Red tides are large toxic algae blooms. Clams can become contaminated with the toxins, which are harmful to humans, causing tingling in the lips, tongue, face, neck and fingertips; headaches; dizziness; nausea and, ultimately, death if you consume enough of the toxins. If you harvest your own clams, never harvest them from reddish-brown water or in areas with posted warning signs. Contact your physician or a poison control center or go immediately to an emergency room if you believe you've ingested contaminated clams.
- Epicurious Food Dictionary: Clam
- USDA National Nutrient Database: Mollusks, Clam, Mixed Species, Cooked, Moist Heat
- University of Maryland Medical Center: Protein in Diet - All Information
- University of Maryland Medical Center: Omega-3 Fatty Acids
- Office of Dietary Supplements: Vitamin B12
- Office of Dietary Supplements: Iron
- Office of Dietary Supplements: Selenium
- Massachusetts Department of Health and Human Services: Red Tide Fact Sheet
Christine Gray began writing professionally in 1997, when a trade publishing company hired her as an assistant editor. She wrote her first screenplay in 1998 and has been covering health and nutrition since 2009. Gray graduated with a Bachelor of Arts in English literature from the University of Michigan.