Tuna is a high quality protein with almost no fat. It contains all essential amino acids required by the body for growth and maintenance of lean muscle tissue. And canned tuna can be a good source of heart-healthy Omega-3 fatty acids.
At the same time, tuna contains mercury. Note that canned tuna fish has less mercury than tuna steaks, and light canned tuna has less mercury than white canned tuna (Albacore). Nevertheless, in March 2004, the FDA recommended that women who are pregnant or nursing, planning to become pregnant, or feeding a young child limit the amount of fish they eat and eat fish with low levels of mercury.
The Environmental Protection Agency provides guidelines on how much canned tuna it is safe to eat. Roughly speaking, the guidelines recommend one 6 oz. can of light tuna a week for those weighing less than 110 pounds and two cans a week for the rest of us.
Bottom line - tuna, like most things, is good in moderation and not good in excess. Since tuna is so tasty, economical and healthy when eaten in moderation, I've included recipes that make one can of tuna go a long way.