Beginning September 2004, U.S. supermarkets are required to label salmon as farmed or wild. Ask for line-caught Alaskan fish first. The healthiest populations and habitats exist in Alaska.
Fresh-caught, wild salmon is available nearly eight months of the year, with high quality "frozen at sea" (FAS) line-caught fish available during the interim.
Wild Alaskan Coho salmon, frozen at sea, is our first choice.
Wild Alaskan Chinook (also called King) salmon, fresh, is our second choice. Two caveats: Fresh "Atlantic" salmon is generally farm-raised—the name refers to the species, not the fish's origin. Avoid wild Chinook salmon from British Columbia; these fish were found to have the high levels of PBDE contamination.(October 10, 2004)
Canned salmon is also a good choice. All canned salmon is wild, plus it is less expensive than fresh or frozen. Check the label for its place of origin.
A draft advisory from the Food and Drug Administration and the Environmental Protection Agency containing new proposed guidelines on fish consumption was circulated at a meeting of the FDA's Food Advisory Committee December 10, 2003, in Washington, D.C. Recent FDA testing has indicated that canned albacore, known as white tuna, contains almost three times as much mercury as canned "light" tuna. The proposed advisory stated that although mercury levels in tuna vary, tuna steaks and canned albacore generally contain higher levels of mercury than canned light tuna. In the spring of 2004, the FDA issued recommendations that pregnant and nursing women, women of childbearing age and children limit their consumption of canned albacore tuna and tuna steaks to no more than 6 ounces per week and light tuna to no more than 12 ounces per week.
While albacore is a biological type of tuna, "light" tuna may be biologically classified as skipjack, bluefin, yellowfin, and tongol. All types except tongol may be labeled "chunk light" or "solid light", while only tongol may be labeled "chunk light". Our recommendation: when you choose to eat tuna, either purchase canned light tuna or if buying canned albacore, purchase water-packed premium Pacific Albacore from a reputable supplier who has had the mercury levels tested by an independent lab.
Choose water-packed tuna rather than oil-packed. The added oil used in canning mixes with some of the tuna's natural fat. When you drain oil-packed tuna, some of its omega 3 fatty acids also go down the drain. Since oil and water don't mix, water-packed tuna won't leach any of its precious omega-3s.
Specialty brands of Premium or "Gourmet" canned Pacific tuna provide the most omega-3 oils of all types of canned tuna. This is because these smaller, often family-owned tuna fisheries catch their tuna in the cold waters of the Pacific by hook and line trolling. As soon as a fish is hooked, it is brought aboard and fresh-frozen. Large commercial fisheries typically catch their tuna in the warmer waters of the Atlantic using "long lines" that lay deep in the water and are harvested only every 24 hours.
Specialty brand tuna is also processed differently. The larger commercial canneries, such as Starkist®, cook their fish twice. First, they bake the fish whole on a rack, which causes a loss of natural beneficial oils, but makes the fish easier to de-bone. After the bones are removed, the fish is put into the can—along with flavorings like vegetable broth, and additives such as pyrophosphate or hydrolyzed casein—and cooked again. Specialty tuna products are typically packed into the can raw and cooked only once, so all their natural juices and fats remain in the finished product.
Canned in water and drained, 6 ounces of light meat tuna typically provides a little less than .5 gram of omega-3 fatty acids, while light tuna canned in oil and drained provides a little more than 0.3 grams of omega-3.
In comparison, tested specialty brands of albacore have been found to contain up to 2.97 grams of omega 3 fats in a 100 gram (3.5 ounce) serving. For this reason, we suggest looking for suppliers of specialty canned albacore tuna that have their product regularly evaluated by an independent lab for mercury content. Canned albacore products can also be recommended if the level of mercury they contain is no more than 0.5ppm (parts per million, which is the same as 500ppb, parts per billion).
The canning process does not affect the mercury content of canned tuna; it is the type of fish that is canned that determines the level of mercury. Again, because of the data made public in the most recent FDA/EPA proposed advisory, we recommend choosing canned "light" tuna.
When it comes to fresh and frozen tuna, your best choice would be one of the species classified as "light" tuna: skipjack, bluefin, yellowfin, and tongol.
We would be comfortable recommending 1-2 servings per week for most healthy individuals who are not battling immediate health problems.
We recommend that pregnant women, nursing mothers and other individuals who are concerned about mercury levels in their diet exclude large fish like swordfish, king mackerel (ono), shark and tilefish.
Consumption of fresh or frozen tuna steaks should also be limited to no more than 6 ounces of one of species of tuna classified as "light" per week. For canned tuna, we suggest choosing "light" tuna and eating no more than 6 ounces once a week and possibly less if health problems are present. A pregnant or nursing mother who weighs less than 135 pounds should eat no more than 4-ounces of canned tuna per week.(February 1, 2004)
Children under six should eat less than one half a can of tuna (3 ounces) per week. Specific weekly limits for children under age six range from one ounce for a twenty pound child, to 3 ounces for a child weighing about sixty pounds.
When choosing other types fish, their mercury content is the main concern, and will vary with both the species of fish and where it was caught.
In addition to wild Pacific salmon, other fish species with low mercury content that are recommended by the Environmental Working Group and the U.S. Public Interest Group include flounder, haddock, shrimp, scallops, farm-raised trout and catfish.
We do not recommend farm-raised fish because they are much higher in fat than wild caught fish and contain much more omega-6 than omega-3 fats.
Because mercury contamination varies geographically, it's a good idea to learn about specific "Fish Advisories" that might exist for fish from the rivers or lakes where you live. You can get this information by contacting your local health department. On the Internet, you can also review information about these local fish advisories at the Department of Health Local Fish Advisory Website.
For our in-depth discussions of the issues surrounding the question of "What fish should I buy?", just click on the following links:
Is there any nutritional difference between wild-caught and farm-raised fish? Is one type better for me than the other?
Is canned tuna a good source of omega 3 fats? How much omega 3s can I expect to consume when eating canned tuna?
Should I be concerned about mercury in fish and what fish are safe to eat?
Is it true that pregnant women should not eat tuna or salmon due to the high mercury content of these foods?