As a dietitian, I had the same reaction to this as if I had read "kids are eating too many fruits and vegetables" or "kids are playing outside too much".
Tuna, like other ocean fish, is a nutrition powerhouse. A single serving packs lean protein and omega-3s, both essential for normal development, into less than 150 calories. And as an added bonus, tuna is convenient, widely available, and affordable. Is there really a trend toward tiny tuna lovers and, if so, does this warrant concern or accolades?
The Mercury Policy Project report is not a peer-reviewed study or review of studies, so its claims require a closer look.
Claim #1:"Canned tuna is the largest source of methylmercury in the US diet, contributing 32 percent of the total, and is a major source of mercury for children."
A closer look: For this claim to be meaningful, the amount of mercury in kids' diets would need to be concerning. Or at least close to concerning. Or at least measurable. The latest scientific data shows that, among children, the "average blood mercury levels for 2005-2008 were not reported because the proportion of results below the limit of detection was too high to provide a valid result." So, not only is the level of mercury in kids' diets not problematic, it's not detectable.
Claim #2:"Canned tuna is served in many school lunch programs."
A closer look: The list of United States Department of Agriculture foods available to schools includes over 40 beef, chicken, pork, and turkey options, but only two kinds of fish, catfish and Alaskan pollock. Foods on this list account for about 15-20 percent of foods served with school lunch. Among the remainder of offerings, tuna is not a very common option, according to the School Nutrition Association. Their 2012 Back to School Trends Report asked about the most popular lunch and breakfast choices in schools and tuna was not on the list.
So what is the entire Mercury Policy Project report about too much tuna in school lunches based on? The lead author, Ned Groth, was interviewed by Food Chemical News, which reported:
"Additionally, there are some questions to be asked about the report. Groth admits his organization didn't conduct a survey to find out how commonly tuna is served in schools, adding that he's heard 'anecdotal' references to the frequency of tuna served in lunches of a friend's grandson in New Jersey."
Claim #3:"Children should not eat albacore tuna."
A closer look: Essentially all seafood contains traces of mercury and has since the beginning of time. Though Mercury Policy Project's report is called "Tuna Surprise," the average mercury levels found were expected. Chunk light tuna, light skipjack tuna, and albacore tuna all contained average mercury levels at least 40 percent lower than the
There was little to no consideration in the report for the other 999,999.44 or more parts per million of the fish - lean protein, omega-3s, selenium, etc. Of the three types of tuna looked at, albacore tuna is the richest source of omega-3s. Stripping it from kids' diets means stripping out those brain-building healthful fats too.
The bottom line: There is nothing to suggest kids are eating too much tuna or fish of any kind, and in fact the science shows they aren't eating enough. While we know the average level of mercury in kids' diets is not detectable, 90 percent of children do not meet the Academy of Nutrition and Dietetics suggested intake for fish-based omega-3s. The Mercury Policy Project report not only solves a problem that doesn't exist; by scaring people away from a relatively popular type of fish, tuna, this report may unfortunately contribute to the real risk, seafood- and omega-3-deficient diets.
Written by Jennifer McGuire, MS., RD
A registered dietitian with the National Fisheries Institute.