Shellfish isn’t just tasty, it’s good for you too. It’s high in iron, which transports oxygen around your body and vitamin B12, which helps turn food into energy. Oysters and clams are a good source of zinc, which supports your immune system. Shellfish does have around 50 mg of cholesterol per 3-ounce serving. But cardiologists agree that saturated fat is more detrimental to blood cholesterol levels than dietary cholesterol. And most shellfish offer some omega-3s, one of the types of fat that can actually improve your cholesterol. Unlike larger seafood species, shellfish are low on the food chain, so they don’t accumulate harmful contaminants like mercury.
Ask at the fish counter what’s freshest. And use your nose: shellfish should smell like the sea and nothing else. Shells of fresh oysters, clams and mussels should be either tightly closed or just slightly opened. If they’re open and you tap them, they should close. If they don’t close, they’re not alive. Don’t buy them. Make sure your fishmonger displays the National Shellfish Sanitation Program (NSSP) tags. This program oversees commercial shellfish and certifies that they are harvested from waters that are safe. Wild shellfish gathered by amateurs is not regulated by the NSSP.
There’s an old adage that says you should only eat shellfish in months with the letter “R” in them, as in, September through April, because the water temperatures are colder during those months. But that bit of kitchen wisdom is outdated because monitoring ensures that shellfish are not harvested during toxic algae blooms, which can occur in warmer waters.
Remember that fresh shellfish are alive, so you don’t want to smother them in a sealed plastic bag. Place clams, mussels and oysters in a bowl covered with a wet clean towel. Put a few ice cubes on the towel so that it stays damp and keep the bowl in the coldest part of the refrigerator, which is usually on the bottom, in the back. Drain off any water that accumulates in the bowl. Use within a day or two.
Pregnant women, children and the elderly. Eating shellfish raw can also be risky for people with certain medical conditions. Check with your doctor. Cooking shellfish kills any pathogens that could be in it. (Of course, anyone with a shellfish allergy should avoid it in any form.)