A. Canned salmon, tuna, sardines, kippered herring, and other types of fish are pretty much on a par with fresh fish. They give you as much heart-healthy omega-3 fatty acids as fresh fish, and sometimes more.
Oily fish are fish that contain at least 10% fat, most of which are the healthier omega-3 oils. In Australia, the oiliest fish include: canned salmon and sardines, some varieties of canned tuna, salmon, gemfish, blue-eye trevalla, blue mackerel, oysters and arrow squid.
Now that's for salmon. Sardines contain significantly less mercury than salmon, so even if you had two standard-sized cans of sardines (~3 ounces / ~84 grams drained), that's still only ~6 ounces of a safer fish in terms of heavy metals. In fact, you could have 4–5 cans of sardines and still be safe!
Sardines
Sardines provide 2 grams of heart-healthy omega-3s per 3 ounce serving, which is one of the highest levels of omega-3 and the lowest levels of mercury of any fish.
It's generally safe for all population groups, including pregnant women, to consume 2-3 serves of any type of tuna or salmon a week, canned or fresh. Canned tuna usually has lower mercury levels than other tuna because tuna used for canning are smaller species that are caught when less than 1 year old.
Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish. Another commonly eaten fish, albacore ("white") tuna, has more mercury than canned light tuna.
A Harvard study found that consuming just one to two servings of sardines every week provides enough omega-3 fatty acids to reduce your chances of heart disease by more than one-third.
Still, small amounts of mercury can pose a risk to young children, unborn babies and the babies of nursing mothers, so the recommended servings of even low-mercury canned light tuna and salmon are no more than 2 to 3 servings per week of 3 to 4 ounces for folks who fall into those categories.
Canned fish is healthy all the way! With canned fish brimming with nutrients and the lining of the can being update by the canned food industry, there is no reason not to include this healthy food into your diet.
Commercially sold fish that may contain high levels of mercury include shark (flake), ray, swordfish, barramundi, gemfish, orange roughy, ling and southern bluefin tuna. In freshwater environments containing mercury, some species of fish may contain high levels of mercury.
It's packed with protein and is one of the healthiest canned fish you can eat. That's why making it a regular part of your diet is a good idea, especially if you want to give your body the benefit of some real protein power.
Most Aussie brands get a sustainability tick from Greenpeace. Look for pole- and-line-caught tuna, which are hooked one by one, avoiding by-catch. Think twice about yellowfin, which is generally less sustainable than skipjack. If the tin doesn't list the type of tuna, don't buy it.
Canned foods in particular usually contain high levels of sodium. One way to reduce your salt intake with canned food, like tuna for example, is washing. Studies show that rinsing reduces the amount of sodium in canned tuna by 80%.
Canned light tuna is in the “Best Choices” category and it is fine to eat 2 to 3 servings per week. We recommend that you eat a variety of fish. You may wish to try other affordable fish in the “Best Choices” category such as canned salmon or sardines, frozen fish, or fresh fish that are at a reduced price.
Oil vs Water
Tuna packed in water will contain fewer calories and less fat but also allows for the loss of omega 3 fatty acids to occur. Water-packed also dilutes the natural juices and flavors contained within the fish and can lead to a more rounded and less refined taste.
All types of canned salmon (pink, chum, coho and red sockeye) are nutritious choices. Choose canned salmon with the bones so that you get the most calcium. Look for the lower sodium (salt) versions.
Andrew Clarke, Associate Professor of Food Science at the University of Missouri-Columbia, "Fatty acids, such as omega-3s, are components of the oils and triglycerides, and therefore are not highly soluble in water. Rinsing [with water] is not likely to reduce omega-3s from the drained fish.
Water-packed sardines just won't have the same rich flavor and can taste a bit water-logged. Oil, however, locks in the fish's flavor and keeps each sardine super-moist. Opt for olive oil, rather than other oils, as its savory characteristics really complement the sardines.
Canned tuna tends to be high in salt (sodium). An average tin can have 0.5g of salt (300mg of sodium) per tin, which is high per 100g. High salt diets can cause high blood pressure and increase risk factors for a stroke.
Skipjack are the smallest of the major tuna species, while yellowfin are larger. So, the fact the canned tuna in Australian cupboards is likely to contain smaller species is already a bonus when it comes to reducing mercury risk.
Salmon, Wild-Caught (including canned)
Wild-caught salmon is low in contaminants, including mercury and lead. And some salmon, like pink and sockeye, from well-managed fisheries worldwide (particularly in Alaska), also tick the box for being lower in mercury and lead.