I asked Tim in the livespill.
“@ld13 - two main negatives with canned stuff. I just read something last night about the protein scores for canned fish being way lower than their fresh counterparts. Second, anytime something has been dead for a long time it is likely to lose phytonutrients. Go deep sea fishing and have sushi/sashimi 5 minutes after you have caught a fish and you can taste the difference. Compare the color of canned peas to frozen or fresh ones, similar idea. When in doubt go for fresh and natural”
Now, I’m guessing the phytonutrients part doesn’t really apply since those are in plants…
As other people said, make sure the can doesn’t have a plastic lining (BPA). It’s pretty easy to find it without a lining. It’s also pretty easy to tell if the fish was wild caught or not as it will usually say, at least for salmon. I eat almost all canned fish just because it is cheaper, and you can’t really get some of it fresh or even frozen. I eat salmon, anchovies, sardines, and oysters. I’d be interested to learn about whether the non-salmon stuff is farm raised or wild caught, it if it really matters, especially for the oysters (they are nutritious as hell).