Fresh tuna is naturally low in sodium, with only about 45 mg per 100 grams of raw yellowfin. Canned tuna, however, tells a different story. The processing and added salt can push sodium levels several times higher, making the answer depend entirely on what form of tuna you’re eating.
Fresh Tuna vs. FDA Sodium Standards
The FDA allows a food to carry a “low sodium” label if it contains 140 mg or less per serving, and a “very low sodium” label at 35 mg or less. Raw yellowfin tuna comes in at roughly 45 mg of sodium per 100 grams, which puts it well within the low sodium range and just slightly above the very low sodium cutoff. For anyone watching their salt intake, a fresh tuna steak is one of the lowest-sodium protein sources you can find.
The American Heart Association recommends no more than 2,300 mg of sodium per day, with an ideal target of 1,500 mg for most adults. A typical 3-ounce portion of fresh tuna uses up only about 2% of that upper limit, leaving plenty of room in your daily budget.
How Canning Changes the Numbers
Canning introduces salt both as a preservative and a flavor enhancer. The difference is significant. One ounce of canned tuna packed in water contains about 70 mg of sodium. The same amount packed in oil jumps to around 118 mg. Scale that up to a standard 3-ounce serving and you’re looking at roughly 210 mg for water-packed tuna and over 350 mg for oil-packed.
A 3-ounce serving of regular canned tuna can reach about 320 mg of sodium, which is roughly seven times what the same amount of fresh tuna contains. That’s still not extreme for a single food, but it adds up quickly in a sandwich with bread, condiments, and pickles.
Some of that sodium also comes from processing additives like sodium acid pyrophosphate, which helps maintain the fish’s color and texture during canning. These additives contribute to the total sodium count on the nutrition label even beyond the salt itself.
Water-Packed vs. Oil-Packed Tuna
If sodium is your primary concern, water-packed canned tuna is the better choice. At about 70 mg per ounce compared to 118 mg for oil-packed, the gap is substantial. Over a full can, you could save 150 mg or more by choosing water over oil. The trade-off is a slightly drier texture, which most people compensate for by adding a small amount of olive oil or mixing the tuna into a salad.
No-Salt-Added Varieties
Several brands now sell canned tuna labeled “no salt added,” which brings the sodium content much closer to fresh tuna levels. These products skip the added salt during processing, so the only sodium present is what naturally occurs in the fish. If you’re on a sodium-restricted diet, these are worth seeking out in the canned fish aisle. Just check the nutrition label, since “no salt added” doesn’t always mean zero sodium. The fish still contains its natural sodium, typically in the range of 40 to 50 mg per serving.
How Tuna Compares to Other Proteins
Among canned proteins, tuna actually performs relatively well. A 3-ounce serving of canned chicken contains about 410 mg of sodium, nearly 100 mg more than the same serving of canned tuna. Canned salmon and other shelf-stable meats tend to fall in a similar range or higher.
Fresh proteins are a different comparison. Raw chicken breast, like raw tuna, is naturally low in sodium at roughly 50 to 75 mg per 100 grams before any seasoning. The sodium spike happens with processing, whether that’s canning, brining, curing, or adding sauces. So the real dividing line isn’t tuna versus other meats. It’s fresh versus processed.
Keeping Tuna Meals Low in Sodium
The tuna itself is only part of the equation. A classic tuna salad sandwich can climb past 800 mg of sodium once you factor in two slices of bread (around 200 to 300 mg), a tablespoon of mayonnaise (about 90 mg), and any pickles, mustard, or cheese on top. If you’re tracking sodium carefully, these additions often matter more than which type of tuna you chose.
A few practical ways to keep the total down: use no-salt-added canned tuna or fresh tuna steaks, swap regular bread for low-sodium varieties, and season with lemon juice, black pepper, or herbs instead of salt-heavy condiments. Mixing canned tuna with avocado instead of mayonnaise cuts sodium while adding healthy fats. Draining and rinsing canned tuna before eating can also wash away some of the brine, reducing sodium by a modest but meaningful amount.