Mercury in Tuna Still a Concern, Consumer Reports Says

Kathleen Doheny

December 09, 2010

December 8, 2010 — Mercury levels in tuna remain too high, according to a new investigation by Consumer Reports.

"Mercury in tuna is still a problem,'' says Jean Halloran, director of food policy initiatives for Consumers Union, who was part of the team involved in the new report, issued today.

It will appear in the January issue of Consumer Reports.

"There has been concern about mercury in fish for quite a while," Halloran tells WebMD.  "There has been growing concern about tuna."

Consumer Reports found the average levels of mercury in white or albacore tuna have gone up since it scrutinized results in 2006 from FDA testing in 2002 and 2004 of mercury levels in canned tuna.

The seafood industry takes exception to the report. The new report is ''simply a retread of a 2006 report that does a disservice to its readers by using tried and true tactics to exaggerate concern," says Gavin  Gibbons, a spokesperson for the National Fisheries Institute in McLean, Va., who reviewed the report for WebMD.

Mercury in Tuna: New Findings

In the latest investigation, Consumer Reports sampled 42 cans and pouches of tuna, both white (also called albacore) and light, bought mostly in the New York metropolitan area or online.  An outside lab analyzed the samples.

White or albacore had more mercury than light, Halloran's team found.

Samples of white tuna had 0.217 to 0.774 parts per million (ppm) of mercury, averaging 0.427.

A woman of childbearing age who ate 2.5 ounces of any of the samples would be over the intake deemed safe by the Environmental Protection Agency (EPA), Consumer Reports says.

Samples of light tuna had less: 0.018 to 0.176 ppm, with an average of 0.071.

The previous FDA database found that 0.35 ppm was the average for white and 0.118 for light.

Mercury in Tuna: What to Do?

Consumer Reports has stricter recommendations than do the FDA and EPA.

The EPA and FDA recommend that women of childbearing age, pregnant or not, along with young children, avoid some fish and eat fish and shellfish that are lower in mercury. Among the fish to be avoided: shark, swordfish, king mackerel, and tilefish, all high in mercury. Mercury can accumulate in the body, and even low exposure has been linked in pregnant women and young children to problems in hearing, learning, and other conditions, Consumer Reports says.

For the lower-mercury fish, the EPA and FDA suggest women of childbearing age and young children limit their eating to up to 12 ounces (about two average meals) a week of fish and shellfish, including up to 6 ounces of white tuna.

The lower-mercury fish include shrimp, canned light tuna, salmon, pollock, and catfish, according to the EPA and FDA.

According to Halloran, Consumer Reports recommends that pregnant women avoid canned tuna and choose lower-mercury seafood instead. Women of childbearing age and young children especially should limit how much canned tuna they eat, Halloran says. Consumer Reports recommends:

  • Children weighing less than 45 pounds should eat no more than 4 ounces of light or 1.5 ounces of white tuna a week.

  • Children weighing more than 45 pounds should not eat more than 4 to 12.5 ounces of light or 1.5 to 4 ounces of white tuna, depending on their weight.

  • Women of childbearing age should limit tuna to 12.5 ounces of light or 4 ounces of white a week.

  • Older women and men should limit tuna to 14.5 ounces of light or 5 ounces of white a week, but if they eat fish more often should stick to low-mercury varieties.

Eating fish is healthy, the report stresses, as it provides protein, vitamin D, and omega-3 fatty acids. Omega-3s have been shown to reduce heart attack and stroke risk and may help prevent certain cancers, cognitive decline, and some eye diseases. During pregnancy, omega-3s help in developing the fetal brain and visual system, the authors write.

Industry Views on Mercury in Tuna

In a statement, Gibbons also says: "Consumer Reports' suggestion that pregnant women limit the amount of fish they eat, outside of the FDA's four fish to avoid, is reckless and has the potential to harm public health."

He mentions the risk of omega-3 deficiency.

He points to a variety of well-respected organizations that promote regular eating of seafood as healthy choices.

Tuna is the second most popular seafood in the U.S., according to a 2009 poll by the National Marine Fisheries Services. Per person, Americans ate 2.5 pounds of canned tuna last year. Shrimp was No. 1, with 4.1 pounds eaten per person.

Mercury in Tuna: What's Next?

Halloran says they're urging the FDA to do more testing and release more test data that she says they have in hand but have not released.

The FDA does have more information on seafood and mercury, says Douglas Karas, an FDA spokesman. "We do have more sampling that has not yet been formalized and published yet," he writes in an email.


Jean Halloran, director of food policy initiatives, Consumers Union.

Gavin Gibbons, spokesperson, National Fisheries Institute, McLean, Va.

Douglas Karas, spokesman, FDA.

FDA web site: "What You Need to Know About Mercury in Fish and Shellfish." "Top 10 Consumed Seafoods."


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