Ah, the lowly can of tuna how far it is has risen! Whether you spread it on a baguette, put a scoop on top of a fresh, crunchy green salad or slip it between a piece of cheese and a slice of whole grain bread for a tuna melt, there are few things a can of tuna cant do.

In the age of the coronavirus pandemics shelter-in-place mandates, canned tuna is especially relevant. Because it comes in a can and is packed with omega-3 fatty acids and protein, its one of the few healthy food staples that you can grab at the grocery store in bulk and let sit in your pantry until you need it. This means fewer trips to the grocery store, which is always a plus these days.

If a stroll down the canned fish aisle leaves you scratching your head, though, we dont blame you: The number of tuna options out there is overwhelming. Theres tuna in olive oil, tuna in water, chunk light tuna, yellowfin tuna the list goes on and on.

So, which tuna choices are healthiest? Lets take a look.

First things first: How much tuna is too much tuna?

While fish is generally lauded as an excellent source of protein and healthy fat, it also contains mercury, which can be toxic for the body in large quantities. According to nutritionist Tamar Samuels , founder of All Great Nutrition and co-founder of Culina Health , fish and seafood tend to be higher in mercury than other foods because mercury emissions released into the air from coal-fired power plants and other industrial sources settle into the ocean, thus affecting fish.

The U.S. Food and Drug Administration and Environmental Protection Agency recommend limiting intake of high-mercury fish and seafood (including tuna and other large predatory fish like shark, swordfish, tilefish and king mackerel) to no more than six ounces a week, and one can of tuna is typically five ounces, Samuels told HuffPost.

If youre pregnant, that recommendation is even lower. Because high mercury levels can have a negative impact on developing fetuses, the Environmental Working Group suggests pregnant women consume 25% less high-mercury fish than the FDA and EPA recommendation.