Fish is undoubtedly one of our most nutritious, varied sources of protein, and it’s especially good for cancer survivors — quick to cook, easy to digest, and full of B vitamins and important nutrients such as omega 3 oils. Yet despite all these benefits, the mere fishiness of fish – and the sheer mystery of what to buy and how to judge quality — can put people off from buying or cooking our water-borne bounty.
Our little guide aims to take the angst out of choosing seafood. If you aren’t ready to take the plunge, especially if you’re in treatment and don’t feel like cooking, canned fish is a great alternative to fresh to get the benefits. For the sake of the oceans’ future, whether buying canned or fresh always look for sustainably fished or farmed products. (See “Ann’s Tips” below for some helpful hints on checking for freshness.)
What Fish Should I Buy?
Cold Ocean Fish
These species have the most omega 3 oils, and come in all shapes and sizes, from tiny sardines to giant tuna.
- Small ocean fish: sardines, herring, mackerel, grey mullet. Sardines and herring are rich sources of omega 3. They can be eaten whole, bones included. Their fine, soft bones are an added source of calcium. Try them baked, pickled, canned, or grilled. If possible, grilling is best done on an outside barbecue to minimize the fishy smell. Fish are a safer option for grilling than red meat. They cook quickly and produce less fat during cooking, both factors that can reduce the production of carcinogens. Nonetheless, don’t eat grilled fish every day.
- Large ocean fish: salmon, tuna, arctic char, mahi-mahi, Chilean sea bass, sable. For big predator fish like tuna, avoid eating too much to keep unwanted levels of mercury out of your diet. Predator fish feed on smaller fish, and as they grow in size, mercury gradually builds up in their systems.
Most of the larger species can be bought in filets or steaks, and lend themselves to being grilled, poached, or baked. Poaching and baking have the least smell when cooking. The AICR recommends that before grilling thick fish steaks, marinate them in olive oil and herbs. Grill 4-5 minutes on each side.
Firm White Fish
- Halibut, sole, cod, pollock, haddock, grouper, swordfish, striped bass, catfish. These are lean, mild-flavored, and full of nutrients such as vitamins B6 and B12, and minerals like potassium and selenium. They are a good choice if you are new to cooking fish, as their firm flesh can stand a bit of overcooking and their taste isn’t overpowering. Roast or bake them in fillets or steaks, or use them in soups and stews like our Quick Fish Stew.
Flaky White Fish
- Flounder, black sea bass, red snapper, trout, sea trout, whiting, tilapia. Also lean, mild, and nutrient-rich, these are more delicate in texture. They mix especially well with vegetables. Cook fillets ‘en papillote, or roast the fish whole. Tilapia is not as nutritious as other fish, largely because it is typically over-farmed, which depletes it of nutrients. Tilapia is included in this list because it is an inexpensive and widely available source of lean protein, with two caveats: take care to only buy US farmed fish, and don’t eat it as a source of omega 3s.
- Mussels, clams, scallops, oysters, shrimp, crab, lobster. Alas, despite their delicious taste, these should be avoided during chemo, since shellfish that isn’t completely fresh can cause food poisoning. If you are on chemo, that “bad” mussel will send you straight to the emergency room.
Wait until you’re done with treatment, then go for it. Shellfish has essential minerals such as calcium, iron, zinc, and selenium, and many are also rich in vitamin B12. Their culinary possibilities are almost endless: Mussels and clams can be steamed with herbs and garlic and added to pasta or seafood soups; shrimp and scallops can be blended into salads, soups, or risottos; lobster is simple to boil, the crab can be made into cakes – we could go on and on.
Buying fresh fish is extremely important. Seek out a really good fishmonger or buy from your local greenmarket. A really fresh fish has bright, unsunken eyes, and shiny, lustrous scales, with the inside of the gills a deep red when you lift them up. It should have only a faint smell of fish. If it smells too fishy, the eyes are concave, or the gills are pale, you’re looking at a fish that has been too long out of water. When a fish has been packed in ice, the eyes can go cloudy, but if the inside of the gills is a deep red, it’s still okay to buy.
When buying fish fillets, if you’re not sure of your fish vendor, choose a whole fish you like the look of, and ask for it to be cleaned, scaled, and filleted for you.
Don’t eat shellfish such as mussels and clams if their shells are broken before cooking, throw them out, or if they don’t open during cooking.
is a great way to cook fish if your experience is limited. If your experience with cooking fish is limited or you’re unsure if you can handle fish aroma right now, you’ll appreciate cooking fish “en papillote,” or fish that is steamed in a sealed parchment paper package like in this Fish en Papillote or a spicier version of the same dish. For Asian-inspired fish dishes, try our Lemon Soy Baked Fish or our Fish with Tangerine Miso Sauce.