Is Tuna Surprise Damaging Your Child's Brain?

The Mercury Policy Project says even small amounts of tuna—especially albacore—could be doing harm to kids.
Have kids? You might want to opt for peanut butter instead of tuna when it comes to lunch. (Photo: JEWEL SAMAD/Getty Images)
Sep 19, 2012· 2 MIN READ
Clare Leschin-Hoar's stories on seafood and food politics have appeared in Scientific American, Eating Well and elsewhere.

Sorry, Charlie. Children should not eat albacore tuna, says environmental group Mercury Policy Project, in what’s sure to be a contested report issued today.

You heard us. No tuna salad sandwiches, no tuna casserole, and forget about that gooey tuna melt, unless you’re making it with light tuna, and even then, don’t serve it up to your munchkin more than once a month.

Why? Because the group says mercury levels in albacore tuna, still well below FDA guidelines, are high enough to impact the brain of a young child.

“What we are concerned about in “Tuna Surprise” is the much subtler risk of barely noticeable but significant effects on the brain development, learning ability, etc. that may be occurring in kids with blood mercury levels greater than 5 ug/L,” Edward Groth, the study’s author, tells TakePart.

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The group tested 59 samples of canned tuna sold to schools and used in USDA-subsiized school lunch programs and found average mercury levels that ranged from 0.118 parts per million (ppm), to 0.560 ppm. Since 2004, FDA guidelines for methylmercury found in tuna were set at no more than 1 ppm with a safety margin of x10. The Vermont-based Mercury Policy Project’s own testing for mercury in tuna mostly mirrors that done by the FDA itself, with results falling far below the 1 ppm limit.

To be clear, the study is not talking about mercury poisoning. As Groth says, they’re raising the issue of subtle effects on brain development, but the report may leave parents scratching their heads on what they should do, particularly since tuna is an affordable, important source of protein for many families, and one loaded with essential fatty acids. Indeed, the report says there is no “bright line between safe and unsafe exposures,” and that “the majority of U.S. children currently fall well within this [safe] consumption level.”

So why the fire alarm? Groth says the current FDA definition of safety is out of date, since more recent studies have show adverse effects can occur at levels previously considered safe. Industry experts have been pressuring the FDA to update their mercury consumption guidelines for several years, yet an FDA draft report on the risk and benefit assessment of fish consumption has languished in the agency since 2009.

Gavin Gibbons, spokesman for the National Fisheries Institute, says the Mercury Policy Project report is doing a disservice to public health.

“Even the USDA dietary guidelines say Americans don’t eat enough seafood,” he says. “So you’re targeting a population that doesn’t eat enough seafood to begin with, and you’re using what is essentially a fake food safety scare to perpetuate a myth.”

As we reported earlier this spring, if we’re looking at the health benefits of seafood, what we know is that Americans aren’t eating enough fish, and the Mercury Policy Project report says most Americans eat only about 100 grams of tuna—less than four ounces a month.

The worry, they say, applies to children under 55 pounds who eat tuna more than once a week, and more so for children who eat tuna every day—a very tiny fraction of the population.

So should the study send you to your child’s school cafeteria demanding that tuna be thrown out of the school lunch program? Not necessarily. Tim Fitzgerald, the scientist who developed seafood contaminant guidelines for the Environmental Defense Fund, says the key here is not to focus on albacore and mercury, but to encourage children to change up the kind of seafood they’re consuming.

“There needs to be a variety of low-mercury choices available to kids at school, like salmon, sardines and shrimp. If this report helps schools expand the variety of seafood they offer, then that’s a good thing,” he tells TakePart.