Is canned fish as good as fresh?

Fresh fish is expensive, intimidating, and goes off in two days. That combination is why most people who intend to eat more fish do not. Canned and frozen solve all three problems at once, and for the reasons fish is on the LP3 plate in the first place they give up almost nothing.

Take sardines, which are the best case. A can holds about twenty grams of protein, close to a gram of the long-chain omega-3s that are the point of eating oily fish, and, because the soft bones come with it, a useful share of a day's calcium. The omega-3s survive canning; they are fats, and canning does not remove fat. Per dollar, sardines and mackerel carry more omega-3 than anything else in my book, by a distance. Canned salmon works anywhere canned tuna does, and frozen fillets go from freezer to oven without thawing. If you satisfied the entire seafood recommendation with a can of sardines and a bag of frozen salmon, you would have done it correctly and spent very little.

How much: two to three servings a week, a serving about the size of your palm. That is about where national guidance lands: the Dietary Guidelines ask for at least eight ounces of seafood a week, the American Heart Association for one to two servings. Salmon is the default, farmed or wild. Sardines and mackerel are the omega-3 bargain. Cod, haddock and tilapia are excellent lean protein but low in omega-3; they count as protein, not as your oily fish. Shellfish are very lean, and mussels are absurdly cheap.

Why fish stays on a plate that leaves red meat off: in the largest study of vegetarian diets, 73,308 adults, the group that ate plants plus fish had the lowest mortality of any diet group, below the vegans. In a British cohort of 48,188, fish eaters had thirteen percent less heart disease than meat eaters and none of the extra stroke seen in the vegetarians. Both are observational. Both point the same way.

Two things to watch on the can. Salt: sardines and salmon are canned with it, so look for the no-salt-added versions or drain well, and rinse canned beans, which removes a good share of theirs. And tuna, the one fish to keep an eye on for mercury if you eat it often. Canned light tuna sits on the FDA's Best Choices list; albacore, the white tuna, is a Good Choice, one serving a week and no other fish from that list the same week.

Mercury more generally, without the panic. It accumulates up the food chain, so the concern is with large, long-lived predators, swordfish, shark, king mackerel, bigeye tuna, tilefish, and not with the small oily fish I am recommending. Sardines, salmon, cod and shellfish are all at the low end. For most adults eating two or three servings a week of those, it is a non-issue, and the weight of evidence is that the benefit of the fish outstrips the risk. The exception is real and specific: if you are pregnant, trying to be, nursing, or feeding young children, the FDA and EPA publish a chart of sixty-two fish sorted into three lists, it is revised periodically, and you should follow the current one rather than this paragraph. Notice why that advice exists. It was written because pregnant women were eating too little fish, not too much.

Chapter four of The LP3 Diet is the seafood chapter, and the recipes include two for sardines specifically because they convert people who were certain they hated them.