Over the last decade, there has been a growing debate concerning the consumption of tuna from a box or can. The primary concern has been centered on the results of tests that revealed the mercury levels in fish, including tuna, is on the rise. While this is true, it is immensely important to put this information into its proper context. While mercury is toxic to the human body, it would have to be consumed at a consistent level on a regular basis for it to have long term effects.
According to a recent article by Eating Well, recent reports that six percent of canned light tuna that were tested and analyzed had as much mercury in it as a regular can of albacore was somewhat misleading. The article suggests that many failed to consider that 94 percent of the light tuna tested had less than one-third of the mercury content of the average can of albacore tuna. The article also revealed that the mercury content in most canned or boxed tuna is so small that the only ones that would be at risk are small children and infants. This is one reason that pregnant and nursing mothers are advised to limit their tuna consumption.
In 2004, the FDA issued a warning that suggested that the mothers of childbearing age and young children limit their tuna consumption to 12 ounces of fish with low mercury content, such as canned light tuna, shrimp and scallops. The warning also advised this same group to limit the consumption of high mercury fish to six ounces per week. Finally, the warning suggested completely avoiding high mercury swordfish, shark, tile fish and king mackerel. The purpose of this warning was to help this particular group maximize its omega-3 intake without increasing its exposure to mercury, which can have the opposite impact of the omega-3 fatty acids in fish, subsequently thwarting the healthy development of the nervous system.
It is worth noting that Prevention.com lists canned tuna as one of the healthy foods that can backfire when too much of it is consumed within a given period. Because of the mercury levels in canned tuna, what is otherwise a healthy, low-calorie go-to, can actually have a reverse effect, when it is consumed in larger quantities. In addition to the negative impact that mercury can have on the development of the central nervous system, it can also have a negative impact on a person’s vision, speech and hearing. Prevention.com suggests that a person, regardless of age, should limit their consumption of canned or boxed tuna to three to five cans per week maximum. They also suggest to swap out tuna on other days for fish that have lower mercury levels, such as shrimp, mercury and Pollock.
While the consumption of boxed and canned tuna should be monitored and managed, it is still safe to eat in low doses; however, young children and women who are childbearing age, should still use caution.