Nothing Fishy About These Fish!

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.