Health claims for tuna just keep getting fishier. The venerable consumer-advocacy group Consumers Union fires the latest salvo in the July issue of its Consumer Reports magazine. Fears that methylmercury, a neurotoxin, can damage a fetus's developing brain led the group to recommend a stringent rule for expectant moms: Lay off tuna entirely.
The magazine advises pregnant women not to eat canned tuna, regardless of whether it's chunk light or albacore. Light tuna is typically found to be lower in mercury than white tuna, aka albacore, so it's often recommended as a more palatable substitute for its more expensive cousin. "For a pregnant woman, even a short-term exposure to a high mercury level is something to be concerned about," says Jean Halloran, director of the Consumer Policy Institute at Consumers Union. "What mercury can do is interfere with nervous tissue connecting up. You dont want anything to interfere with the hardware of the brain being laid down properly. Its very much a precautionary measure. Were not saying if youve had a can of tuna fish while you were pregnant youve damaged your baby forever."
The new Consumers Union recommendation is based on the group's analysis of data from Food and Drug Administration tests, posted on the FDA's Web site. It's caused quite a stir because it's a departure from the FDA's own fish advisory, which the agency just reaffirmed early this month. The FDA says that women who might become pregnant, are pregnant, or are nursing can eat 12 ounces -- about two average meals -- of light tuna a week. It cautions women to eat half that amount of albacore.
Not surprisingly, the U.S. Tuna Foundation, an industry trade group, disputed Consumer Reports and denounced the magazine on its "Truth About Tuna" Web site, quoting the FDA guidelines. "In an era when heart disease is spiraling and obesity has become an epidemic, Consumer Reports [has] done a great disservice in discouraging canned tuna consumption through inaccurate and incomplete facts," argued Anne Forristall Luke, president of the U.S. Tuna Foundation.
Michael Bender, executive director of the Mercury Policy Project, cites USDA research in saying that canned tuna is "the most heavily consumed fish" by pregnant women and children. The United States is second only to Japan in feasting on the world's prolific tuna catch. There's so much concern about mercury in tuna that California's attorney general, Bill Lockyer, tried -- and failed -- to have warning labels about mercury put on cans of tuna. Whole Foods recently joined Safeway and Wild Oats supermarkets in posting government warnings in stores around the nation about mercury lurking in seafood.
Given the health warnings about tuna, say consumer advocates, it's troubling that the federal government is giving nursing mothers vouchers that can be redeemed for cans of tuna. The USDA's Food and Nutrition Service's Women, Infants and Children program, commonly known as WIC, feeds more than 8 million low-income women and children every month. Women who are pregnant, postpartum or breast-feeding, along with their infants and children up to age 5, are eligible. In addition to food vouchers for staples like milk, cheese and eggs, participants receive counseling on nutrition and breast feeding. The program's reach is so vast that it serves 45 percent of all babies born in the United States, a commentary on how many babies are born into poverty.
Nursing mothers who are exclusively breast feeding their infants in their first year can receive up to 26 ounces of canned tuna per month through WIC. Both albacore and light tuna are eligible, although some states, like Texas, exclude albacore. A nursing infant is not as vulnerable to the toxin as a developing fetus. That's because methylmercury does not pass as easily through breast milk as it does through the placenta and the bloodstream, according to Dr. Leo Trasande, the assistant director of the Mount Sinai School of Medicine's Center for Children's Health and the Environment in New York. Halloran from Consumers Union concurs. "For nursing mothers, the issue still exists, but its not as extreme," she says. "Mercury will end up excreted in mothers milk, but its not quite as direct as the passage in the bloodstream from stuff you eat."
Yet, Trasande stresses, there is still some risk to the developing infant's brain, and he recommends that all women of childbearing age -- whether pregnant, nursing or planning to become pregnant -- limit their tuna consumption to about one can per week, whether chunk light or albacore, as long as they're not being exposed to mercury from other fish sources, a recommendation that's more conservative than the FDA's. Consumer Reports offers that women of childbearing age who aren't pregnant eat no more than three cans of chunk light tuna per week or one can of albacore tuna.
Susan Acker, a USDA spokesperson, writes in an e-mail that the program is merely following the FDA's guidelines. She states that the "amount of tuna WIC makes available to exclusively breastfeeding women (26 ounces per month of canned white, light, dark or blended) is within recommended levels." She also says that WIC informs women about the risks of getting too much mercury in their diet by distributing the FDA's guidelines "What You Need to Know About Mercury in Fish and Shellfish" at thousands of WIC clinics. But that message doesn't always get through.
Susan Levin, a nutritionist at the Physicians Committee for Responsible Medicine, a nonprofit group that promotes the health benefits of vegetarian and vegan diets, did a two-week dietetic internship at a WIC office in Seattle in 2004. "They didn't do any education about mercury in fish, and Seattle is a pretty liberal place," she says. "I never saw them talk about the risks behind eating tuna."
Today, the foods offered in the WIC packages are under review, and albacore tuna may be on the chopping block. The National Academies' Institute of Medicine did an official review of WIC's food packages in April 2005, offering guidance on how they should be updated based on the latest nutritional information. It recommends that the program make salmon available to nursing moms as well as light tuna, and that albacore be excluded from the program altogether. The USDA has yet to implement the recommendations.
Some state WIC programs are taking matters into their own hands. Hawaii, which serves more than 30,000 women and children through WIC, persuaded the federal WIC program to allow it to offer canned salmon as well as light tuna -- it doesn't offer albacore at all -- to nursing mothers. Salmon, which eat lower on the food chain than tuna, typically accumulate much less mercury. The WIC program in Hawaii advises nursing mothers about mercury in fish, as well as gives mothers recipes for how to cook with canned salmon, since they may not be as familiar with ways to cook it. Then, the women can choose if they want vouchers for light tuna or salmon. Halloran from the Consumers Union approves of that option: "Almost all canned salmon is Alaska wild salmon. Canned salmon is a good substitute for tuna. It's extremely low in mercury."
Yet even the most aggressive public-health efforts can't get at the root of the real problem -- the pollution from coal-fired power plants that's causing more mercury to show up on our dinner plates.