Fish is great food. A six-ounce portion ( about the size of a deck of cards ) is a complete serving of protein. When talking about serving sizes, it's important to remember that most Americans eat way too much, of everything. I want to remind you that a serving of grains ( rice or pasta or cereal ) is one-half cup and I never met anyone in this counrty who actually eats only one-half cup, of anything.
The issues with fish is that there are concerns about mercury. We all can benefit from the Omega-3 fatty acids in fish but the mercury can be very problematic for developing nervous systems ( fetuses and young children ). Mercury is found in the larger fishes, close to the top of the food chain. If you are pregnant or nursing, thinking of becoming pregnanct or feeding young children, it's important to get the methylmercury facts straight.
So, twelve ounces of seafood are permissable per week. There are four fishes to avoid completely due to higher mercury levels: shark, sworfish, tilefish and king mackerel, per the FDA and EPA. There are other sources that list fresh tuna, marlin, grouper, orange roughy, Chilean sea bass and Spanish mackerel to that avoid list, as well. Canned tuna fish should be obtained from a can labeled "light" ( not white albacore ).
There are quite a few sources out there to help you decide which fishes are safest and which are high on the mercury- alert lists. Try out nyc.gov/health and click- on the Health Topics tab. See cfsan.fda.gov and select mercury for the topic. Blueocean.org has helpful information and a means to immediately text FISHPHONE to get information while you are actually buying and eating. Technology, ain't it great?
Make sure the fish you choose is well- cooked: flakey all the way through and no glistening, wet center. No sushi, no sashimi, no tartar, no ceviche, no seared Ahi tuna when you are pregnant. That doesn't mean that you can't eat in Japanese restaurants, you know. Cooked "sushi" like California rolls is just fine. It's not the ethnic food, it's the raw fish that you need to avoid.
So don't be afraid of fish and don't forget to get those important Omega-3s. Think small, oily fishes and stay away from the big, meaty, steak- like fishes that take a long time to grow-up and have more time to absorb more mercury. Sardines anyone? Well, maybe salmon.