Doctors, nutritionists and dietitians are unanimous that Americans as a whole need to eat more fish. The high-quality protein of fish is leaner than meat, and the fats in fish are heavy in healthy omega-3 fatty acids rather than the saturated fats in meat. However, many consumers are reluctant to increase their fish consumption because of the risk of mercury contamination.
About Mercury
Mercury is a contaminant found in both fresh and salt waters around the world. A limited quantity occurs naturally, but the majority stems from industrial pollution. Your body readily absorbs methyl mercury, the kind found in water, and stores it in your tissues. In small amounts this is not a major concern, since your body manages to cleanse itself in the course of a year or so. However, if you become pregnant or nurse while there is a high level of mercury in your system, it can cause your child long-lasting developmental damage.
Mercury and Fish
Methyl mercury in the water contaminates the food supply of various fish species and begins to concentrate in their tissues just as it does in yours. The older and larger a fish is, the more mercury it is likely to contain. Furthermore, large predators such as tuna, shark and king mackerel accumulate greater amounts of mercury because of their position at the top of the food chain. In short, researchers are able to estimate the safety of a given species by examining its food source and by physically testing the tissues of individual fish.
Seafoods Low in Mercury
There are several varieties of fish and shellfish that are naturally low in mercury. Molluscs, including clams, mussels and scallops, are all low-mercury options. So are crustaceans, with shrimp and crab classed as low-mercury and lobster as moderate. Fish that primarily prey on crustaceans or insects, including salmon, trout and char, also are low or moderate. A fourth safe choice is flat fish, including place, sole, skate, flounder and halibut, all of which have low to moderate mercury content. The herring family, including anchovies and sardines, are safe, and so are smaller members of the mackerel and tuna families.
Seafood and Health
The health benefits of eating seafood are clearly understood, and no authoritative source advises cutting it from your diet. Be selective in choosing your seafood and you'll still be able to enjoy it frequently. The Food and Drug Administration recommends two 6-oz. portions of low-mercury seafood each week, and no more than two higher-mercury seafood meals in a given month.
