As National Seafood Month kicks off, a number of retailers and restaurants are unveiling significant discounts and promotions. These deals are set to further boost an already thriving sector, as recent market research indicates that the global seafood industry reached close to $360 billion in 2023 and is projected to exceed $800 billion by 2032.

Shrimp tops the list of seafood in the United States, followed by salmon and then tuna, according to the National Fisheries Institute. “The global demand for tuna is also rising,” highlights LeeAnn Weintraub, a registered dietitian and nutrition consultant in Los Angeles.

Although Japan and various European nations remain the leading tuna consumers, Americans still account for a considerable share—over a billion pounds of canned and pouched tuna are consumed annually in the U.S. Notably, when it comes to grocery shelf space, only coffee and sugar surpass the sales of canned tuna.

What exactly is tuna?

Tuna is a type of saltwater fish found in every ocean, including the Atlantic, Pacific, and Indian Oceans. While there are 15 types of tuna worldwide, Weintraub identifies the most common varieties in Western countries as albacore, bigeye, yellowfin, bluefin, and skipjack—the latter being the most widely sold type in the U.S., making up over 70% of the total tuna sold.

Many enjoy larger cuts of these varieties raw in poke bowls, sushi, or sashimi, but freshly caught tuna can also be prepared by searing, boiling, frying, baking, or broiling. The most commonly consumed form of tuna is canned tuna, which is already gutted, cleaned, precooked, filleted, and processed. “Canned tuna is favored due to its convenience, long shelf life, and affordability,” explains Jen Messer, a nutrition consultant and registered dietitian.

The most traditional way to enjoy canned tuna is in a tuna salad, which combines tuna with mayo and other ingredients like mustard, lemon juice, parsley, diced celery, diced onions, diced pickles, and seasonings such as salt, pepper, paprika, or garlic powder. Various versions of tuna salad can be used as a spread for sandwiches or as a component in casseroles or macaroni salad.

Is tuna healthy for you?

This high protein content, combined with its low calorie count—a five-ounce can contains just 80 calories—makes tuna “an excellent choice for weight management,” according to Messer. Additionally, it can help you feel satiated more effectively than many other food options and promote lean muscle mass development.

In addition to its vitamins, minerals, and protein, “tuna is also rich in omega-3 fatty acids,” adds Weintraub. Omega-3s are linked to improved symptoms of ADHD and depression, enhanced brain function, and reduced inflammation. These benefits, alongside the other nutrients found in tuna, “can help reduce the likelihood of heart disease, dementia, and vision issues,” she notes.

“Studies also suggest that consuming fish, including tuna, can lower the risk of colon and rectal cancer,” mentions Messer. This is one of the reasons “the Dietary Guidelines for Americans advocate for including fish in a healthy diet,” she points out.

Is it safe to eat tuna daily?

However, there are important considerations to avoid consuming too much tuna—in particular, being mindful of additional ingredients like mayonnaise, which can be high in saturated fat and calories.

Canned tuna can be quite high in sodium, containing about 280 milligrams—or roughly 12% of the recommended daily intake—in just one can. Diets high in sodium can raise the risk of heart disease, kidney problems, and stomach cancer.

Mercury levels are another concern, especially for pregnant or breastfeeding women, as elevated mercury can be detrimental to developing nervous systems. “Generally, larger tuna species such as yellowfin and bigeye contain higher mercury levels due to bioaccumulation,” warns Messer. This bioaccumulation occurs when larger fish consume smaller fish that carry mercury, “leading to increased mercury concentrations in larger species,” she adds.

Therefore, “regularly eating substantial amounts of these tunas (and albacore, which usually contains three times more mercury than canned light tuna) can heighten mercury exposure,” says Messer. To mitigate the risk, the Food and Drug Administration advises selecting skipjack or “light” tuna, particularly for young children and pregnant or breastfeeding women.