How Much Canned Tuna Is Safe To Eat?

Americans don't eat as much tuna as they used to, but they still eat a lot—hundreds of millions of pounds each year, in fact—and Consumer Reports thinks that might be too much.

Consumer Reports released an article on Thursday, asking the Food and Drug Administration to reconsider its new recommendations for weekly tuna consumption. Among the many suggestions, which included asking pregnant women that they eat no tuna at all, the consumer advocacy organization is pushing for significant cutbacks in the amount of canned tuna Americans eat. The problem, according to the organization, is that tuna contains more mercury than the government agency is letting on.

“We’re particularly concerned about canned tuna, which is second only to shrimp as the most commonly eaten seafood in the U.S.,” the report said. "Given its popularity and its mercury content, canned tuna accounts for 28 percent of Americans’exposure to mercury, according to an analysis by an EPA researcher published in 2007‘‘."

The organization isn't merely concerned about the packaged foodstuff—it has committed to a series of specific recommendations for canned tuna consumption, which is charted above. Albacore tuna, which has been found to contain more mercury, should be eaten very infrequently—someone weighing 150 pounds should eat no more than a can of albacore tuna per week, by Consumer Reports' estimates. Light tuna, on the other hand, can be eaten a bit more frivolously—the organization suggests no more than 13 ounces per week, or just under three cans.

Despite Consumer Reports' plea, there is still much debate about how much mercury tuna actually absorbs, and whether what mercury it does contain poses any serious harm to humans. The FDA, for its part, has defended its recommendations, which encourage the consumption of tuna, even among pregnant women and children. The National Fisheries Institute, which represents seafood companies and restaurants has also taken serious issue with the warnings about tuna. "Minimal research would have presented reporters literally hundreds of independent seafood studies from the FDA to the World Health Organization that clearly demonstrate the net benefit gained from eating seafood, like tuna,” the Institute told the Washington Post on Thursday.

Roberto A. Ferdman is a reporter for Wonkblog covering food policy, consumer business, and Latin American economics. He was previously a staff writer at Quartz.