Fish contains 17 to 25 percent protein and is generally a good source of B vitamins, especially niacin, B12, and B6. Fatty fish are good sources of vitamins A and D. The small, soft, edible bones of fresh sardines and smelts and canned bone-in fish like salmon are valuable sources of calcium. Saltwater fish also contain minerals, including iron, iodine, phosphorus, and selenium. Fish is low in cholesterol (50 to 90 milligrams per 100 grams).
• Omega-3s: Omega-3s are types of healthful polyunsaturated fat. They help improve cardiovascular health by controlling cholesterol and reducing blood pressure. They’ve also been linked to brain function and mental health benefits such as lowered rates of depression and dementia. Darker-fleshed fish that swim in cold, open waters, such as tuna, herring, and mackerel, store fat in their flesh and are high in omega-3s. Freshwater fish from cold waters, like lake herring, lake trout, salmon, and whitefish, are also high in omega-3s. In general, white-fleshed fish, such as cod, tilapia, or flounder, are low in all types of fat, including omega-3s. That’s because they store fat in their livers (as in cod-liver oil). What about omega-3 supplements? You can take them to obtain some of the benefits, but they don’t contain all the other nutrients in fish.
• Dietary recommendations: Although the Dietary Guidelines for Americans do not make specific recommendations regarding seafood, other public health organizations, like the American Heart Association and American Dietetic Association, recommend two servings weekly because seafood is a quality protein source that is high in “good” fats.
• Proper Portions: A 6-ounce fish fillet is about the size of the contents of a can of tuna when raw. When cooked, it will weigh about 4.5 ounces. Allow 12 ounces per portion uncooked for whole fish, 10 ounces for pan-dressed (headless) fish, 8 ounces for bone-in fish steaks.
At the market
• Choose a quality fish market: Choose a fish market with knowledgeable salespeople. Fish should be displayed attractively and surrounded by plenty of clean crushed ice.
• Be flexible: The best approach to buying and eating fish is to aim for variety. You’ll consume fish of varying omega-3 levels and from a variety of sources without over-dependence on one. Let freshness be your guide. It’s easy to substitute one fish for another (see Types of Fish), so if the mahimahi looks and smells fresher than the pompano, buy it instead.
• Handle properly: When shopping, ask for your fish to be packed with a separate bag of crushed ice to keep it cold. Refrigerate whole fish up to two days; fillets and steaks one to two days. Place the fish in a plastic bag, then top with a zip-top plastic bag filled with ice. Thaw frozen fish in the refrigerator. To defrost safely and quickly in one to two hours, place the fish in a sealed plastic bag in a bowl of cold water, changing the water often.
Ways to Save
• Know your local fish. “When local fish are abundant, the price goes down and the quality goes up,” says Joe Lasprogata, buyer for Philadelphia seafood wholesaler Samuels & Son. In the East, try Atlantic black sea bass and weakfish; Gulf amberjack and black drum in the South; Great Lakes Coho salmon and smelts in the midwest; Pacific sardines and albacore tuna on the West Coast.
• Try whole fish. Whole fish shrink less than fillets when cooking, giving you more value for your per-pound price. Whiting, croaker, porgy, and Pacific rockfish can be great values. Also, consider summer flounder (sometimes called fluke), red snapper, farmed striped bass, and Arctic char.
• Consider canned. Canned fish is an excellent budget-friendly option. It can also be a nutritious one, particularly varieties like canned tuna and salmon that are low in sodium and rich in omega-3s. Keep them―along with flavorful sardines and anchovies―on hand for fish cakes and salads.
For more money-saving tips, check out Fish on a Budget.
How to buy the best
Whole fresh fish
• Look for shiny skin; tightly adhering scales; bright, clear eyes; firm, taut flesh that springs back when pressed; and a moist, flat tail.
• Gills should be cherry-red, not brownish.
• Saltwater fish should smell briny; freshwater fish should smell like a clean pond.
Fresh fillets, steaks
• When buying white-fleshed fish, choose translucent-looking fillets with a pinkish tint.
• When buying any color fish, the flesh should appear dense without any gaps between layers.
• If the fish is wrapped in plastic, the package should contain little to no liquid.
• Ask the fishmonger to remove any pin bones, which run crosswise to the backbone.
• Look for shiny, rock-hard frozen fish with no white freezer-burn spots, frost, or ice crystals.
• Choose well-sealed packages from the bottom of freezer case that are at most three months old.