Ask Well: Canned vs. Fresh Fish
Q: Does canned fish like tuna and salmon have the same nutritional value as fresh fish?
The canned products are certainly cheaper, available and convenient.
A: Yes, fresh and canned fish have roughly the same nutritional value, according to experts and the United States Department of Agriculture’s National Nutrient Database. And whether to eat one over the other isn’t an obvious choice, because each has advantages and disadvantages, said Alice Lichtenstein, a professor at Tufts University’s Friedman School of Nutrition Science and Policy.
Canned tends to be cheaper and easier than fresh, with a longer shelf life. But it also tends to have more sodium than fresh, she said, and many people prefer the taste of fresh.
Canned fish is also more likely to be wild than farmed, said Kristin Kirkpatrick, a registered dietitian and manager of nutrition services at the Cleveland Clinic Wellness Institute; some types of farmed fish have been found to be high in pollutants. Plus, canned fish such as sardines generally provide more calcium, because the calcium-rich bones are softened by processing and therefore more likely to be eaten.
In terms of mercury levels, a particular concern for pregnant women, Dr. Lichtenstein said she suspected that canned fish like salmon probably contains less mercury than fresh, because smaller-size fish, which carry less mercury than larger ones, are more likely to end up in cans.
If you choose canned, fish canned in oil is more likely than fish packed in water to retain more omega-3 fatty acids, considered good brain food, Ms. Kirkpatrick said, because the oil helps keep the nutrients in the fish. Oil adds extra calories, but if packing in oil means someone will eat fish they wouldn’t otherwise, it’s worth it, Dr. Lichtenstein said.
“Bottom line,” Ms. Kirkpatrick said, “it’s important to get your omega-3s, and one of the easiest and most affordable ways to do that is to go canned. You won’t be skimping on nutrition.”
