Studies have shown the health benefits of omega-3 fatty acids found in fish such as mackerel, sardines, herring, lake trout, tuna, and salmon. These types of fish, referred to as "fatty fish," contain 2 particular kinds of omega-3 fatty acids—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
These nutrients are essential for healthy fetal development and may also have positive health benefits for infants, children, and adults. However, reports concerning high levels of certain toxins—especially mercury—have raised concerns about the safety of eating seafood. Mercury in the air falls into the ocean where fish live and go up the food chain, eventually accumulating in some fish and shellfish that feed on other marine creatures.
Recent studies conclude that the benefits of eating certain fish outweigh the risks, in most cases. Currently, the Food and Drug Administration (FDA) advises women who are pregnant, women who may become pregnant, nursing mothers, and young children to avoid eating shark, swordfish, king mackerel, and tilefish, and to limit consumption of albacore (white) tuna to 6 ounces per week. According to the FDA, five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.
Additional information about mercury and seafood is available at the EPA website.