by Craig Weatherby
We offer seafood that’s naturally low in mercury... and because predatory fish accumulate it as they grow, we sell only smaller tuna and halibut.
While we'll continue to offer only lower-mercury species, the evidence virtually proves that this policy is not essential to ensure safety.
Instead, a preponderance of the human and lab research shows that most seafood is safe for children and adults to consume as frequently as desired… and it demonstrates this in a compelling, mutually reinforcing fashion.
In fact, the only fish shown to pose any mercury-poisoning risk are the few, uncommonly consumed species that are high in mercury and low in selenium.
This small category only includes marine mammals (whales, seals), certain fresh-water fish, and a very few ocean fish (such as shark) that are not commonly consumed in America.
Consumer Reports goes off the rails... and hits child health
In the latest instance of counterproductive fear-mongering, the January, 2011 issue of Consumer Reports magazine offers dubious, potentially detrimental advice for young children and pregnant/nursing women.
Consumers Union (CU), the magazine’s publisher, tested 42 samples of canned tuna and found nothing new.
Then, while offering no evidence for their advice, they told children and pregnant women to eat less tuna than the U.S. government considers safe.
The U.S. FDA and EPA say that women of childbearing age and young children may eat up to 12 ounces a week of light (e.g., skipjack or tongol) tuna or other lower mercury seafood, including, within that limit, up to 6 ounces per week of white (albacore) tuna.
But Consumers Report advised pregnant women, “as a precaution”, to avoid eating tuna, and advised that children who weigh more than 45 pounds limit their weekly intake from 4 to 12.5 ounces of light tuna or from 1.5 to 4 ounces of white tuna, depending on their weight.
Consumers Report advises children who weigh less than 45 pounds to limit their weekly intake from 0 to 4 ounces of light tuna or from 0 to 1.5 ounces of white tuna, depending on their weight.
To be blunt, there is no scientific basis for this advice, which the best evidence suggests could impair children’s brain development.
And it makes no distinction between smaller, troll-caught albacore (like ours), whose mercury levels are similar to those in light tuna, which U.S. agencies and Consumer Reports consider the safer choice.
Magazine ignores overwhelming evidence for seafood safety
Consumers Report's misguided conclusion reflects apparent ignorance of the actual safety evidence and the selenium-mercury research that explains why almost all seafood is safe.
Publisher CU might respond that, to be cautious, young children and pregnant/nursing women can get omega-3s from low-mercury fish and/or from supplements.
That’s true, but tuna is America’s most popular fish and fish can and should replace the less healthful protein sources favored by kids, from baloney and chicken fingers to hot dogs and burgers.
No other protein source offers the proven benefits of fish and shellfish, while soy and standard, grain-fed meats and poultry exacerbate the pro-inflammatory, disease-promoting excess of omega-6 fats in the average American diet.
As CU acknowledges, “Fish are rich in protein, vitamin D, and omega-3 fatty acids. Omega-3s reduce the risk of heart attack and stroke and might also elevate mood and help prevent certain cancers, cognitive decline, and certain eye diseases. During pregnancy, omega-3s might help in developing the fetus’s brain and visual system.”
Echoing and supporting other compelling human research, the large, landmark ALSPAC study showed that the kids who ate the most fish of any kind enjoyed better brain performance than kids who ate the least fish (Hibbeln JR et al 2007).
We urge you to continuing reading, to learn why mercury fears are misguided… and we recommend the evidence-based rebuttal penned by John Sackton, president of the trade website, Seafoodnews.com.
Fishy fear-mongering is baseless and counterproductive
In 2008, a draft FDA report laid out the evidence from all of the best studies, and confirmed what we’ve been reporting: ocean fish and shellfish are safe (See “FDA Analysis Supports More Fish for Moms and Kids”).
And large, credible studies conducted by university and government researchers (e.g., in the Seychelles Islands and the UK) clearly show that children who eat fish-rich diets display better brain performance than kids who eat fish-poor diets and suffer no adverse effects (See “More-Fish-for-Moms Report Affirmed in Europe”).
The only studies showing any developmental harm from eating seafood (i.e., in the Faroe Islands and New Zealand) involved kids who ate mostly whale or shark meat… with seal meat being risky as well.
As the FDA analysis shows clearly, a key assertion in the Consumers Union press release is highly misleading:
“Some studies have linked even low-level mercury exposure in pregnant women and young children to subtle impairments in hearing, hand-eye coordination, and learning ability.”
In fact, only diets high in whale, seal, and shark—all of which are high in mercury (and PCBs, which affect development) but low in selenium—show any evidence of harm.
Differing study outcomes linked to vital mercury-selenium connection
The varying outcomes of studies that examine the impact of seafood on child development are almost certainly explained by the interactions between selenium and mercury in human bodies.
Marine mammals and shark contain significantly more mercury than selenium.
In contrast, almost all ocean fish contain substantially more selenium than mercury.
Why does this matter? Mercury is toxic for one primary reason… it binds to selenium, rendering that nutrient unavailable for its many essential roles in human health and metabolism.
Further, dietary mercury only becomes toxic when a person consumes more mercury than selenium.
As long as the body has enough “available” selenium (i.e., not bound to mercury), it suffers no harm from even relatively high levels of mercury.
The criminally ignored but scientifically compelling research on mercury-selenium interactions explains why the evidence supports the safety of tuna and almost all other seafood (except whale, seal, and shark).
This is how leading selenium-mercury researcher Nick Ralston Ph.D.—based at the University of North Dakota’s EPA-funded Energy & Environmental Research Center—put it in a 2010 evidence review:
“This may explain why studies of maternal populations exposed to foods that contain Hg [mercury] in molar excess of Se [selenium], such as shark or pilot whale meats, have found adverse child outcomes, but studies of populations exposed to MeHg [methylmercury] by eating Se-rich [selenium-rich] ocean fish observe improved child IQs instead of harm” (Ralston NV, Raymond LJ 2010).
Dr. Ralston noted one caveat: “However, since the Se [selenium] contents of freshwater fish are dependent on local soil Se [selenium] status, fish with high MeHg [methylmercury levels] from regions with poor Se [selenium] availability may be cause for concern”
To learn more about this research, and new safety-ranking system for seafood, see “Most Fish Rank as Very Safe on New, Selenium-Based Standard.”
Of course, any dietary factor—including pure water—can be toxic in extreme excess.
But even fish that is relatively high in mercury doesn’t appear to harm people unless that fish (or the person eating it) lacks sufficient selenium.
Sadly, this statement by CU ignores the repeated scientific findings on mercury-selenium interactions: “The body is slow to eliminate mercury so it can accumulate in people over time.”
In fact, if people have and continue consuming enough selenium from plant foods, seafood, and/or supplements, mercury accumulation from seafood is virtually irrelevant.
We have no quarrel with CU’s advice that women who are pregnant or might become pregnant, nursing mothers, and young children should choose lower-mercury ocean fish that are also rich in selenium and healthful omega-3s.
All of our offerings are low in mercury and offer ample selenium and omega-3s… with our tuna, sardines, mackerel, anchovies, and salmon also being very rich in vitamin D.
Choi AL, Budtz-Jørgensen E, Jørgensen PJ, Steuerwald U, Debes F, Weihe P, Grandjean P. Selenium as a potential protective factor against mercury developmental neurotoxicity. Environ Res. 2008 May;107(1):45-52. Epub 2007 Sep 12.
Consumer Reports Magazine (CR). Mercury in canned tuna still a concern. January 2011 issue. Accessed at http://www.consumerreports.org/cro/magazine-archive/2011/january/food/mercury-in-tuna/overview/index.htm
Consumers Union (CU). New Tests Reinforce Concerns about Mercury in Tuna. Dec. 12, 2010. Accessed at http://pressroom.consumerreports.org/pressroom/2010/12/my-entry.html
Hibbeln JR et al. 2007. Maternal seafood consumption in pregnancy and neurodevelopmental
Ralston NV, Blackwell JL 3rd, Raymond LJ. Importance of molar ratios in selenium-dependent protection against methylmercury toxicity. Biol Trace Elem Res. 2007 Dec;119(3):255-68.
Ralston NV, Ralston CR, Blackwell JL 3rd, Raymond LJ. Dietary and tissue selenium in relation to methylmercury toxicity. Neurotoxicology. 2008 Sep;29(5):802-11. Epub 2008 Aug 9.
Ralston NV, Raymond LJ. Dietary selenium's protective effects against methylmercury toxicity. Toxicology. 2010 Nov 28;278(1):112-23. Epub 2010 Jun 16. Review.
Ralston NV. Selenium health benefit values as seafood safety criteria. Ecohealth. 2008 Dec;5(4):442-55. Epub 2009 Apr 14.
outcomes in childhood (ALSPAC study): an observational cohort study. Lancet 369, 578–585.