Sleeping Like A Neurologically Impaired Baby: Holy Mackerel! Eat Herring Instead

Well, the experts have been flopping a bit on this issue but the basic gist is that there is mercury in the really healthy deep sea fish that have high levels of beneficial omega-3s in them. And since mercury's particularly damaging for small people, pregnant or nursing women and children have had to closely watch their fish intake. (Which is a bummer, since among other benefits it seems that a high intake of the DHA fatty acids in fish could account for better sleep in infants, no small feat.) There are handy lists of fish to avoid, mercury calculators like those here and here, and lists of fish that are safe to eat. Recently it seemed like the evidence weighed in favoring eating more fish over avoiding it for groups watching mercury exposure, but research showing that it's better to consume fish than not while pregnant may have been funded by -- surprise -- the fish industry. So we're back to the longstanding advice that women of childbearing/nursing age should eat 2 servings/week of fish and limit their consumption to specific species (the fish industry study recommended greater consumption without regard to species). One fish that's been hotly debated because it's a beloved kid sandwich food is tuna, which the research shows you should probably limit no matter the type (albacore vs. light).

Testing of fish oil has shown that most is not contaminated with mercury (your grandmother was right about that cod liver oil!) but since supplements aren't heavily regulated you have to choose brands carefully. American Heart has helpful guidelines on supplementing with fish oil.

In a parallel vein, lots of enviro organizations have lists of what's sustainably fished. This site helpfully lets you track down environmentally conscious restaurants serving sustainably harvested fish. And Environmental Defense has a downloadable pocket reference guide to enviro choices re sustainably fished species. But my favorite is the NRDC guide, which combines the mercury warnings with the sustainability info in their wallet card.

The bottom line? Avoid tuna, shark, tilefish (golden bass or snapper), swordfish, orange roughy, bluefish, and sea bass. Eat as much as you want of catfish, anchovies, clams, crabs, pollock, oysters, wild salmon (not farmed, which has PCBs), sardines, sole, herring, tilapia and trout. Also, try to eat lots of fish high in omega-3s like herring, sardines, oysters and salmon. Check out the lists for further fine-tuning of this advice, and try to eat a variety of the safe fish.