WebMD's Top 10 Ways To Make Seafood Safe
By Elaine Magee, MPH, RD
WebMD Weight Loss Clinic - Expert Column
You know that fish is good for you. It's low in saturated fat, rich in protein, and contains the omega-3 fatty acids thought to do all sorts of wonderful things for your body, from helping to protect your heart to easing depression to soothing arthritic joints. Fish consumption in general is thought to reduce the risk of heart attack and strokes and is believed to boost brain function in infants. In fact, it's important for pregnant women to get some seafood because some of the nutrients it contributes are important to fetal brain development.
But you read the news, and you're not about to turn to fish when it might be contaminated with unsafe levels of PCB and mercury! Never fear, the WebMD Weight Loss Clinic is here to help you navigate those fishy waters. Read on.
All About PCBs
PCBs, or polychlorinated biphenyls, were used as insulators in transformers and were banned in the 1970s.
The bad news: Despite the ban, PCBs still exist in our environment and tend to accumulate in animal fat. You'll find PCBs in many places -- in higher-fat beef, full-fat dairy products, the skin of chicken, fatty fish, and larger, older predatory fish.
Recently farm-fed salmon hit the news when the Environmental Working Group (EWG), a watchdog organization, did a study of 10 farmed salmon fillets and found that the PCB levels of the salmon were 16 times higher than in fresh salmon, 4 times higher than in beef, and 3.4 times higher than in other seafood.
But if you think fish has the market cornered on PCBs, think again. A chicken breast has about the same amount and butter has 2 1/2 times the PCBs found in farmed salmon, according to the same Environmental Working Group. PCB contamination is also possible when eating red meat, poultry, eggs, and dairy products, according to the EPA.
And here's the long term perspective: The future looks brighter for fish and PCBs. Levels of PCBs in food have decreased 90% over the past 30 years, according to Terry Troxell, director of the FDA's Office of Plants and Dairy Foods and Beverages.
All About Mercury
Mercury is a well-known neurological and kidney toxin. It exists naturally in the environment, but more is released into the air, land, and water when we burn trash, dump sewage on cropland, and when our factories burn fossil fuel. Mercury has made its way into the fish part of the food chain because it is found in water. The bigger fish, such as pike, bass, and very large tuna, seem to contain more mercury because they eat smaller fish and almost immediately inherit those fish's mercury stores.
The bad news: Because eating fish that contains mercury can damage the nervous systems of unborn babies and may pose a risk to young children, The FDA has written an advisory for pregnant women. Pregnant women can safely eat 12 ounces of cooked fish per week, as long as it's from the lower-mercury species. Which fish have the most mercury? Shark, tilefish, king mackerel, and swordfish tend to top the list.
The good news: One of our most popular fishes -- canned tuna -- contains lower levels of mercury than other types. But that's where the good news ends. The Environmental Working Group advises pregnant women to eat no more than 6 ounces (about one can's worth) of tuna per month -- mainly because this fish is eaten so frequently in America.
Now, how do you put this information into practice? Follow these 10 tips to make sure your fish consumption is within safe guidelines:
- Eating a variety of fish and seafood is a smart way to go. By eating different species of fish, you are spreading out your risk of consuming environmental contaminants that might be in any one of those species. When you have a choice, try to avoid the larger fish that are on the list of higher-mercury types: shark, tilefish, king mackerel, and swordfish.
- Eat wild or canned salmon instead of farmed salmon when you have a choice, and consider eating no more than 8 ounces of farmed salmon per month, according to a recent report from the Environmental Working Group. (But don't get the idea that wild salmon is completely PCB-free; it, too, should be consumed in moderation.)
- Trim any visible fat from your fish before cooking (since PCBs are stored in fish fat) and cook your fish with a method where the fat can drip away while it cooks (grilling, broiling or baking).
- Stick to cooked (not raw) clams, oysters, mussels, scallops, and other mollusks. These filter-feeding fishes can carry waterborne bacteria, viruses, or toxins that can cause severe gastrointestinal problems if they are eaten raw or uncooked. Oysters and clams should be boiled for at least 3 minutes or steamed for 4-6 minutes to destroy harmful microorganisms.
- If you are a big sushi fan (or if you like sashimi or ceviche dishes), make sure the restaurant you go to is a reliable source for sushi and that they use only ocean-dwelling fish in their raw dishes.
- Raw seafood should be kept well chilled, at refrigerator temperatures, even while defrosting.
- Be extra cautious that raw fish juices don't contaminate other foods, especially those eaten raw. All utensils and surfaces used to prepare raw seafood should be thoroughly washed with hot soapy water as soon as possible.
- Remember that the FDA considers up to 1 part per million of mercury in fish to be safe. On average, the goods in the U.S. seafood market contain less than 0.3 parts per million of mercury.
- The top 10 safer fishes to eat are: canned tuna, shrimp, pollock, salmon, cod, catfish, clams, flatfish, crabs, and scallops. According to the FDA, these generally contain less than 0.2 parts per million of methyl mercury.
- Buy your fish at fish outlets that sell lots of fish. That way you are more likely to get fish that hasn't been sitting around too long. And don't be afraid to ask the merchants which fish came in today. Look around. If the seafood counter has a bad smell and looks unclean, chances are their fish isn't the freshest. Buying frozen fish works well, too. Just put it immediately into the freezer if you aren't going to eat it within a day or two. If you're planning to cook the fish within a day or two, put it directly into the refrigerator to thaw (make sure it is in a container that doesn't allow raw fish juices to drip on other items in your refrigerator.)
How Much Fish to Eat?
The FDA recommends eating only one 7-ounce helping per week of large fish such as shark and swordfish, and no more than 14 ounces per week for seafood with lower levels of mercury.
They do however, warn pregnant women and women of childbearing age against eating shark, swordfish, king mackerel, and tilefish, suggesting that they have this type of fish no more than once a month. For other types of seafood, the FDA considers up to 12 ounces of cooked fish per week a safe amount.
The Environmental Working Group advises pregnant women to eat no more than 6 ounces of tuna per month. They advise people to limit farmed salmon to no more than 8 ounces a month, or eat wild or canned salmon instead.