Salmon fillet sprinkled with herbs and garlic on a cutting board

Seafood can sometimes be controversial when it comes to weighing the health benefits and risks. It’s known that seafood can be a good source of protein and Omega-3 fatty acids. However, it can also be associated with unhealthy levels of mercury and other contaminants.

Jay Gibson, clinical dietitian at UC Davis Health, cooks and eats seafood on a regular basis and believes it plays an important role in our diet. In this blog, he offers some nutritional facts and advice for buying, cooking and eating seafood.

What are the benefits of eating seafood?

It's recommended that most people eat about 8 oz. of seafood each week, according to the USDA Center for Nutrition Policy and Promotion.

Here are some of the health benefits for seafood:

  • Good source of protein
  • Fewer calories from fat as compared to meats. (Seafood typically has 5% to 20% calories from fat, while beef has between 30% and 60% calories from fat.)
  • Many beneficial vitamins and minerals, like B-complex vitamins, vitamins A and D, selenium (antioxidant), zinc and iodine
  • Omega-3 fatty acids

Health benefits associated with higher Omega-3 fatty acid intake:

  • Heart health
    • Reduces risk of heart disease
    • Protects against heart attack and sudden death
    • Lowers triglyceride levels
  • Improves eyes and visual activity
  • For pregnant women: increases length of gestation and birth weight
  • Helps build brain structure and is important in fetal and early childhood development
  • Helps build muscles and tissues
  • Reduces inflammation

Variety of shellfish on a plate

What are the risks of eating seafood?

Eating seafood can mean consuming some levels of mercury. This can have damaging effects in the development of the brain, kidneys and nervous system. Pregnant women and young children need to be especially careful to avoid high-mercury fish. The FDA and EPA have guidelines on which fish to eat, and how often to eat them, based on mercury levels.

Other contaminants of concern are polychlorinated biphenyls (PCBs). Although they were banned in 1979, remnants are still found throughout the world. They can accumulate in fat and other organs in fish and animals that eat fish.

Bottom-feeding fish and larger predators caught in contaminated waters contain higher levels of PCBs. Studies show that farmed salmon have more PCBs than wild salmon because of the food they’re typically fed.

What kinds of seafood should you buy?

Variety of raw fish in a glass case at the store

Buy seafood from a reputable source and those that are packaged immediately after being caught. Many commercial fishing boats have packaging centers on the boats to ensure fish stays fresh.

Try to choose a variety of fish that are lower in mercury, such as anchovy, catfish, herring, scallops and canned tuna. Fish like marlin, swordfish and sharks contain higher levels of mercury.

The Monterey Bay Aquarium Seafood Watch program has a list of eco-friendly seafood choices. Some items in the “Best Choices” category include catfish, clams, mussels, oysters, scallops and trout. Seafood you should avoid include halibut, sardines, sharks and bluefin tuna.

What should you look for when buying fish?

Again, make sure to only buy fish from a reputable source. Federal law requires retailers to list the country of origins and whether seafood is wild-caught or farm-raised. When looking to buy at a store or market, take note of how employees handle the fish.

Whole fish should have clear and bulging eyes, red gills, and intact (not torn or ragged) fins. Fish flesh should feel firm, cold, wet, and slippery, but not sticky. Fresh fish should smell like the ocean, not fishy.

How should you handle and cook seafood for the most health benefits?

Seafood should typically be refrigerated at a temperature below 40°F. For frozen fish, it’s best to thaw out overnight in the refrigerator. Just like chicken or meat, wash your hands, utensils and surfaces after handling fish to reduce the spread of bacteria.

Seafood cooks pretty quickly. When baking, heat the oven to 400°F for most fish and cook to an internal termpature of 145°F. A rule of thumb is to cook 10 minutes per inch of thickness.

An easy way to know when fish is cooked is when it turns an opaque color and easily flakes with a fork. For clams and mussels, cook until the shells open. Shrimp, crab, lobster and scallops should be cooked until they're opaque and firm.

Other methods for cooking seafood include broiling, poaching, steaming, sautéing and grilling. Frying fish destroys some beneficial nutrients, and fried fish is higher in fat and calories.

Some healthy ways to add flavor to your fish include: olive oil, pepper, lemon juice, herbs and spices such as parsley, garlic, onions, and moderate amounts of salt.

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