Though they cover 70 percent of the Earth’s surface and are full of life, oceans are also a deep mystery — about 95 percent of them remain unexplored. But the 5 percent we do know about is home to vibrant coral reefs, underwater volcanoes and countless plants and animals. King crabs, oysters and shrimp, and even shell-less animals such as octopus and squid are all considered shellfish, and doctors agree their nutritional benefits are worth diving into.
“Shellfish contain vitamins A and D, and the minerals potassium and selenium, which help protect our bodies from certain cancers and chronic diseases,” says Dr. Graham Colditz, associate director of prevention and control at Siteman Cancer Center. “Vitamin A and selenium are considered to be antioxidants, which can reduce inflammation in the body by getting rid of damaged cells. Sometimes those damaged cells can turn into cancer, so eating enough antioxidants is extremely important. They also boost your immune system.” Meanwhile, vitamin D and potassium build strong bones and reduce the risk of osteoporosis.
Shellfish are full of omega-3 fatty acids, a compound that your body can get only from certain foods. Omega-3s may also help reduce inflammation, and they keep cholesterol and triglycerides in check — a crucially important function, Dr. Colditz explains. “Triglycerides indicate the amount of fat in our blood. There are some fats that are worse for the heart than others, and keeping triglycerides low cuts down on the cardiovascular type of chronic disease development,” he says. “There’s also an impact on heart disease. That’s historically the biggest killer of middle-age and adult populations. High triglycerides can trigger a cascade of bad outcomes.”
Midsummer is the ideal time to enjoy shellfish. They are light, low-fat options for meals and a great way to cut down on red meat — particularly when the humidity is cranked to 11, and hot dogs and hamburgers are starting to get repetitive. “For people who’ve not historically included shellfish in their diets at all, it’s worth trying different options,” Dr. Colditz says. “It’s the same with increasing vegetables: Don’t think there’s just one way to cook or prepare them. There are many different ways to add spice, or to change the flavor or texture. Being open to that is the key to attaining an overall healthy diet.” But be mindful of how shellfish is prepared. Calories add up quickly when lobster is dunked in butter and shrimp is breaded and deep fried.
Mollusca is the biggest and most diverse phylum in the marine world, one that contains aquatic invertebrates from giant squids to slugs. Clams are a part of this phylum, too. These bivalves spend most of their lives in relatively shallow water and use a muscular appendage to burrow and pull their way through the sand. North Americans are probably most familiar with quahogs, the species that includes littleneck clams (great steamed or eaten raw) and half-pound quahogs themselves. Large clams have a tougher texture than small ones, so they’re best when cooked, stuffed or used in chowder.
When they’re not busy picking out World Cup winners or stealthily escaping from aquariums, these squiggly cephalopods (yep, still considered shellfish!) live in bodies of saltwater all over the globe. They’re also a fundamental part of many cooking traditions. In northwest Spain they’re known as pulpo, boiled and served with olive oil and paprika. Octopus pops up in Latin and South American ceviche; it’s used in sushi (called tako), and it’s the main ingredient in a spicy Korean stir-fry dish known as nakji-bokkeum. Properly tenderized in the hands of a skilled chef, octopus is a must-try delicacy.
Crabs make their homes in nooks and crannies in all of Earth’s oceans, many tropical rivers and swamps, and even on land for good measure. Their meat is known for its sweet taste and melt-in-your-mouth texture. In North America, crabs vary greatly in size, from the Bering Sea’s massive king crab (of Deadliest Catch fame) to the much smaller Jonah crab, found up and down the continent’s Atlantic coast. Though it seems like they can live anywhere, certain species are being overharvested; The Monterey Bay Aquarium Seafood Watch counts blue crabs from Chesapeake Bay among North America’s most sustainable options.
Typically oblong and dark in color, mussels can be found in both Midwestern rivers and in faraway seas. Like clams, they have a foot that helps them navigate their environment, and they also have byssal threads — strong fibers they use to latch on to underwater structures. These “beards” aren’t particularly appetizing, so remove them prior to cooking. Once the prep work is finished, they couldn’t be easier to make: Dump a few pounds into a pot, add some kind of liquid (wine, broth, beer), cover with a lid and steam until they open — about five minutes will do. To find the freshest ones at the seafood counter, look for mussels that are tightly closed and have uncracked shells.
Though synonymous with the disc of meat they contain, scallops — those gorgeous fan-shaped seashells — are pretty incredible creatures. They have eyes, a refined nervous system, and they use jet propulsion to motor around the ocean. They’re found throughout the world in religious art, mythology, heraldry and kitschy souvenir shops. Scallops are a sustainable (if expensive) choice for meals, and they’re a snap to cook: Sear them in an oiled pan for just a few minutes on each side, and they’re ready to eat.
In Good Taste is brought to you in partnership with Siteman Cancer Center. Watch for more healthy, seasonal cooking ideas each month.