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Throw it back? Eating too much tuna may mean exposure to unhealthy levels of mercury.
RODALE NEWS, WASHINGTON, DC—The evidence keeps piling up: For pregnant women, or women who could become pregnant, eating tuna is not a good idea.
But advice to stay away from tuna is inflammatory. So inflammatory that, even though the U.S. Food and Drug Administration (FDA) data shows that canned light tuna contains above-average mercury levels, the FDA currently says it’s OK for women of childbearing age (and young children) to eat it. Canned tuna remains the single largest source of mercury in the American diet.
THE DETAILS: Pressure from fishing industry lobbyists, the National Fisheries Institute (NFI), and particularly what was once called the National Tuna Foundation (now part of NFI), makes it very difficult for the agency to properly warn against the mercury levels in the popular fish.
It's not that the FDA hasn't had time to examine the facts about tuna and mercury. I've written about the hazards of mercury in fish since the early 1990s, and watched as the evidence has grown that mercury can cause cognitive impairment in children whose mothers ingested too much during pregnancy—including learning disabilities, motor skills impairment, and short-term memory loss. There is evidence now that safe-exposure levels for mercury are far lower than previously thought.
However, evidence has also accumulated that children of women who eat two or more servings of fish a week have better cognitive function than children of women who eat one serving or less. The FDA and the U.S. Environmental Protection Agency (EPA) have been working jointly on updating a 2004 consumer advisory about fish consumption, which could perhaps clarify the risks of mercury contamination and the benefits of eating fish. Edward Groth, PhD, an environmental health expert and retired senior scientist at Consumers Union, and Michael Bender, head of the Mercury Policy Project, have written to the FDA and EPA with what seems very sensible advice to include in the policy.
Groth and Bender base their suggestions on studies that have appeared since 2004. One is a 2005 study done in Boston, the first with American subjects, that shows that “maternal fish consumption during pregnancy can significantly benefit prenatal cognitive development, while exposure to methylmercury during gestation can significantly damage prenatal cognitive development." Additional evidence, based on an epidemiological study done in New York in 2008, shows the positive effects of fish consumption. The lead author of the Boston study, Emily Oken, MD, of the Harvard Medical School, wrote, “We observed the highest cognitive scores among offsprings of mothers with higher fish intake but lower mercury levels. Beneficial and adverse effects have now been associated with ordinary American levels of fish consumption and methylmercury exposure.”
When the agencies were asked what they planned to do with their 2004 advisory policy, both said essentially the same thing: They are aware of the issues Groth has brought up. The FDA stated, "We look forward to engaging our colleagues at EPA, and in the scientific and public-interest communities, to achieve a science-based resolution."
WHAT IT MEANS: While waiting for the updated policy, the public remains totally confused. Some people have stopped eating fish altogether. Others believe (as the industry does) that tuna is perfectly safe, and eat it frequently. Even some experts believe that the benefits of eating any fish, including tuna, outweigh the risks. Other groups, including Consumers Union, publisher of Consumer Reports, recommend that women of childbearing age and children skip tuna altogether.
Troll-caught albacore = lower mercury albacore
Articles concerning mercury in fish often overlook the difference between troll-caught and long-lined fish. And it's an important difference to those of us making a living catching tuna.
Many articles tend to oversimplify (leading to uninformative conclusions) or list the tuna types in a thick not-so-enlightening paragraph. Both of these approaches do little to help consumers make an informed decision on what kind of albacore to buy – while at the same time pass on incorrect information that hurts family fishing businesses like ours.
Challenges like off-shore corporations, cheap foreign labor, unsustainable fishing regulations outside US waters … they’re hitting our industry hard. But our jobs are made even harder when articles and news reports continue to muddy the waters concerning albacore and mercury. Troll-caught albacore and long-lined albacore do not have the same levels of mercury. Troll-caught albacore has lower mercury levels.
Writers and reporters can easily differentiate between types of albacore and mercury levels by asking two simple questions:
What species of tuna are you talking about?
Albacore tuna is actually one of several species of what we familiarly lump together as ‘tuna’. Often writers lump all tuna species together and cry, “mercury - stay away!” But this is like warning consumers to avoid the entire nightshade family because belladonna is poisonous, forgetting that the tomatoes we love to eat or the petunias we put into pretty flower baskets are part of the same family.
Once you’ve determined the fish you’re talking about is albacore tuna, it’s time to learn a little more.
How is the albacore tuna caught (and how can you tell)?
If it is caught by long-line, it will most likely not say so on the can. These albacore are caught on long long lines full of hooks that are left to sit deeper down in the ocean. Long-lining results in by-catch and fish with higher mercury levels. Some cans may say ‘line caught’, but unless it also states that it is U.S. in origin they most likely mean long-line.
Troll-caught albacore: these albacore are caught one-at-a-time by hook-and-line by people like my parents, who are at sea right now standing on the back deck of their boat waiting for the fish-on bell to ring. Their lures skitter near the surface of the ocean, attracting young albacore who have not had time to accumulate as much mercury in their bodies. Bycatch is almost nonexistent. The Marine Stewardship Council has rated our fishery sustainable.
How can you know if the albacore tuna is troll-caught?
1. Look for the MSC logo on the cans (ours will have them soon)
2. Look for the words ‘troll-caught’ or ‘caught one-at-a-time by hook-and-line’
3. Look for albacore caught by US fishermen
4. Look for a higher fat content in the fish
5. Look for albacore canned in micro (or custom) canneries
For more information:
On troll-fishing http://wildpacificseafood.com/EarthFriendly.html.
On mercury, selenium and a mercury/albacore study done specifically on troll-caught albacore (FDA studies do not factor in catch-methods) http://wildpacificseafood.com/GoodForYou.html
Feel free to email me if you have any other questions at Stephanie@WildPacificSeafood.com. If I can't help, I'll find someone who can. Accurate reporting about our industry is essential if this sustainable low-mercury fishery is to thrive. Thanks for taking the time to learn more.
Here's to great weather and safe fishing!
Stephanie
Light Vs. Albacore Confusion
I'm confused. In another article on this site (http://www.rodale.com/mercury-tuna?page=0%2C1, dated April 29, 2010) the following was stated:
To help you understand what you’re eating, here's a useful breakdown of tuna terminology, courtesy of the Monterey Bay Aquarium:
• Albacore. Albacore tuna is one of the safest fish you can eat, provided it's caught in the U.S. or British Columbia. This tuna is caught when it's younger and therefore has had less time to build up high levels of mercury, but albacore imported from other countries normally contains more mercury. So location is key. Canned albacore is always labeled "chunk white." You can buy American and Canadian albacore tuna from online sources including Heritage Foods USA, Pacific Fleet, MaryLu Seafoods, Wild Planet, and Wild Pacific Seafood.
• Chunk Light. Unlike "chunk white," "chunk light" tuna is a blend of different species and often includes meat from high-mercury bigeye tuna, along with less-contaminated yellowfin. It's best to avoid chunk light tuna. Instead, stock up on cans of American and Canadian albacore.
The current article lists canned albacore tuna as having high mercury levels and canned light tuna as having above average mercury levels. The articles seem to contradict each other. Am I missing something? Is the current article referring to non-USA sourced albacore?